Dynamic covalent chemistry of spiropyrans for synthesis of photoswitched photoinitiators and uses thereof

Abstract

The invention relates to spiropyrans and a method of making the same. In particular, the present invention provides a method of exchanging the indole and salicylaldehyde moieties of spiropyrans in a reversible reaction. The method is used for synthesizing two-color photoinitiators with specific substituents and substitution patterns, which improves two-color volume printing (two-color volume printing). In addition, the invention also discloses a method for locally polymerizing a starting material through two-color photopolymerization.

Description

TECHNICAL FIELD

[0001] The present invention relates to the dynamic covalent chemistry of spiropyrans and its applications. In particular, a method for the synthesis of spiropyrans via exchange reactions is provided. Thus, substitution patterns on spiropyrans can be realized synthetically for the first time. The provided spiropyrans contain specific substituents and substitution patterns and are used as dual color photoinitiators, thereby improving dual color volumetric printing (xolography). BACKGROUND

[0002] Spiropyrans and merocyanines as optical switch molecules

[0003] Definitions of optical switch molecules, photochromic structures and terms used in this field can be found in [Bouas-Laurent, Durr, Pure and Applied Chemistry, 2001, 73, 639-665]. In general, an optical switch molecule is a photochromic compound that is able to undergo a reversible structural change in at least one direction via a photochemical pathway. A typical example is the spiropyran / merocyanine system, as shown below: .

[0004] Colorless spiropyrans are the thermodynamically favored form and undergo a ring opening reaction upon irradiation with UV light to the metastable colored merocyanine form (positive photochromism). The merocyanine form can be a mixture of different isomers, where the bond between the five- and six-membered ring is in the E or Z configuration. Within this invention, the term merocyanine refers to one or more different E / Z isomers. The reverse reaction from merocyanine to spiropyrans can be performed either photochemically or thermally (T-type photochromism).

[0005] Spiropyrans are usually synthesized via condensation of salicylaldehyde and 2- methylenesindoline, which can be obtained by deprotonation of an indolenium salt. The spiropyrans can subsequently be functionalized, especially when it contains suitable functional groups: .

[0006] Direct functionalization of salicylaldehyde is limited due to the presence of free hydroxyl and free aldehyde groups. Salicylaldehyde does not have a direct protecting group. Salicylaldehyde is sensitive to nucleophiles, oxidation conditions, and reduction conditions. It is not possible to perform typical reactions such as halide-metal exchange of bromide with n-butyllithium because the hydroxyl group will deprotonate instead of the desired halide-metal exchange. Furthermore, the hydroxyl group has a strong directing effect and limits direct functionalization to the para position of the hydroxyl group. In addition, the aldehyde as a strong electron withdrawing group deactivates the aromatic system, thus only allowing very reactive reagents for direct functionalization, such as acetic anhydride with aluminum chloride in a Friedel-Crafts acylation reaction. It is not possible to perform other typical reactions such as reduction of the nitro group in the presence of the formyl group of salicylaldehyde because the formyl group will be reduced under similar conditions. Thus, functionalization of salicylaldehyde is limited.

[0007] Dynamic covalent chemistry

[0008] An overview on dynamic covalent chemistry and terminology and definitions can be found in [Yinghua Jin, Chao Yu, Ryan J. Denman, Wei Zhang, Chemical Society Reviews, 2013, 42, 6634-6654; Peter T. Corbett, Julien Leclaire, Laurent Vial, Kevin R. West, Jean-Luc Wietor, Jeremy K. M. Sanders, Sijbren Otto, Chemical Reviews, 2006, 106, 3652-3711; and Rowan et al., Angewandte Chemie International Edition, 2002, 41, 898-952]. Dynamic covalent chemistry describes reversible chemical reactions that are under equilibrium control. The final product distribution at the thermodynamic minimum depends on the relative stability of the final products. Applications of dynamic covalent chemistry can be found in many self-organizing systems such as host-guest interactions, covalent organic frameworks, dynamic combinatorial libraries, drug discovery, polymeric materials. For example, two imines can react in an exchange reaction. Therefore, imines have been widely applied in dynamic covalent chemistry: .

[0009] Currently, dynamic covalent chemistry is limited to a few reactions that are suitable for exchange. These reactions are mainly: aldol reactions, Diels-Alder reactions, metathesis reactions of carbon-carbon double and triple bonds, and exchange reactions of boronate and carboxylate esters, imines, aminals, disulfides, and boronic anhydrides. Importantly, dynamic covalent chemistry has not focused on spiropyrans.

[0010] Photoinitiator

[0011] An overview on photoinitiators and terminology and definitions can be found in [Green, Industrial Photoinitiators A Technical Guide, CRC Press, 2010; Fouassier and Lalevee, Photoinitiators Structures, Reactivity and Applications in Polymerization, Wiley VCH, 2021]. The curing of a material refers to the polymerization of monomers. Depending on the polymerization mechanism, several functional groups have been found to be suitable monomers, including but not limited to acrylates, methacrylates, thiol + alkene, epoxides, oxiranes, oxetanes or vinyl ethers. Photoinitiators initiate polymerization upon light irradiation. The polymerization reaction can proceed in a free radical, cationic, anionic or metal catalyzed way. Photoinitiators are either type 1, which are single compounds that are able to initiate polymerization, or type 2, which require a co-initiator. Type 1 photoinitiators are able to undergo homolytic (free radical) or heterolytic (cationic / anionic) bond cleavage to form reactive species. In subsequent secondary reactions, further species can be generated, which can lead to different polymerization properties, for example amine radicals are initially generated by homolytic bond cleavage, then abstract a hydrogen atom from the environment to form an amine and initiate base mediated polymerization. Type 2 photoinitiators are able to initiate polymerization by two different mechanisms, where the first is the abstraction of a hydrogen from a co-initiator, generating two radicals, and can generate further reactive species from subsequent reactions. The second mechanism is a photo-oxidation-reduction reaction, where an electron is transferred between the co-initiator and the photoinitiator. The photo-oxidation-reduction reaction can proceed by further proton transfer reactions to generate radicals or other subsequent reactions, resulting in further reactive species, such as acids, bases or radicals. Several structural units are known to initiate polymerization, and examples of the most important structural units are shown below.

[0012] .

[0013] Additive manufacturing / 3D printing

[0014] Additive manufacturing or 3D printing can be performed with a variety of techniques and materials and allows to manufacture custom parts. In contrast to injection molding, additive manufacturing enables the formation of more complex structures, saving material and offering the opportunity to the machine to build specialized parts with superior performance. However, most additive manufacturing techniques rely on a sequential layer-by-layer build. Thus, the object is sliced into many layers and printed layer by layer. This inevitably entails certain limitations, namely the need for support structures to prevent overhanging parts from falling apart. Usually, several mechanical steps are involved between the printing of the layers, which leads to long manufacturing times. The starting material for the printing has to be in a form that allows mechanical handling without destroying the object, which limits the starting material to certain powder sizes or viscosities.

[0015] To overcome the limitations of traditional additive manufacturing, volumetric printing has been proposed as a solution. In such a method, the resin is in a container and the solidification does not occur on the container walls but inside the volume by the action of light. This eliminates the need for support structures, allows the use of low and high viscosity resins, allows the formation of soft objects and is not affected by the inhibitory effect of oxygen or water on the surface.

[0016] To overcome the problems of two-photon polymerization and tomographic reconstruction, a two-color photoinitiating system has been developed (xolography). This requires a photoinitiator that, when irradiated with light of a first wavelength λ1, transforms from its thermodynamically stable ground state form A to a metastable ground state species B. When species B absorbs light of a second wavelength λ2, it is able to initiate a polymerization reaction through a form C. Form C is an excited state of B, which generates free radicals, cations or anions through further reactions with or without a co-initiator. In the sense of the present invention, the terms first wavelength, second wavelength and third wavelength can refer to wavelength ranges. For use in a volumetric printing method, the reverse reaction from B to A must be possible to avoid unwanted areas from hardening. The reverse reaction from B to A can be triggered by heat or by irradiation with a third wavelength λ3.

[0017] .

[0018] The above-described two-color volumetric printing technique is called xolography. A two-color photoinitiating system suitable for this method can be based on a spiropyran with a carbonyl moiety [Garmshausen et al. WO2020245456A1]. The two-color photoinitiator described therein is synthesized by a reaction of 2-methyleneindole with salicylaldehyde, which can be post-functionalized in subsequent steps.

[0019] Kenji and Ichiro's JP H0375127A claims three photoswitching molecules for volumetric printing. The molecules described therein are known for their photochromic properties but do not exhibit selective curing where two wavelength beams of light intersect as shown by Neckers [US005230986A, column 6, lines 27-35]. Even though they are able to initiate with dual color irradiation, they show a slow thermal back reaction from B to A which makes them unsuitable for volumetric printing applications. The spiropyrans described therein are synthesized from 2-methyleneindolin and salicylaldehyde.

[0020] Neckers' US005230986A discloses iodinated benzospiropyrans with suitable co-initiators as two-photon radical photoinitiators with the following structure where at least one of the two substituents X1and X3is iodine: .

[0021] The disclosed molecules have limited efficiency for photopolymerization which makes it necessary to use high concentrations [Lee, Neckers, Chem. Mater., 1991, 3, 852-858; and Lee, Neckers, Chem. Mater., 1991, 3, 858-864]. Therefore, the penetration depth of light is limited and the volume suitable for printing cannot exceed 2 millimeters as these authors show [Lee, Neckers, Chem. Mater., 1991, 3, 858-864, Figures 12 and 13]. The iodine substituent acts as a triplet sensitizer in the spiropyran form, whereby the unwanted side reactions generated with first wavelength irradiation alone dominate, where the spiropyrans induce a photoredox reaction and thus form radicals without isomerizing to the merocyanine. The iodinated benzospiropyrans are further limited by a slow thermal back reaction in more viscous media which makes them unsuitable for volumetric printing. The disclosed molecules are all synthesized by condensation of 2-methyleneindolin and salicylaldehyde.

[0022] Two other two-component systems based on spiropyrans have been reported for recording holograms [Jeudy, Robillard, Opt. Commun., 1975, 13, 25-28; Ichimura, Sakuragi, J. Polym. Sci. Polym. Lett, 1988, 26, 185-189]. However, neither is suitable for volume printing, as in both cases the thermal back-reaction is too slow for commercially successful applications on the one hand, and both cause significant polymerization at the first wavelength on the other hand [Lee, Neckers, Chem. Mater., 1991, 3, 858-864]. In both publications, the molecules are synthesized from a condensation of 2-methyleneindolin with salicylaldehyde.

[0023] The reaction of spiropyrans with 3,5-dinitrosalicylaldehyde was proposed to exchange the salicylaldehyde moiety, but no analysis was made [Bertelson, Techniques of Chemistry, Vol. III, Photochromism, Chapter 3]. This reaction was further proposed to be used as a protection strategy for salicylaldehyde. When the reaction was performed as described by Bertelson, a corresponding precipitation occurred. Although this precipitate was assumed to be the exchanged spiropyrans, analysis showed that 3,5-dinitrosalicylaldehyde acts as an acid in the mixture, protonates the original spiropyrans and leads to the precipitation of the protonated spiropyrans without any exchange occurring. Furthermore, in the case of spiropyrans carrying an acyl functional group capable of undergoing this reaction, such as acetyl, the acid was found to catalyze the aldol condensation. Other acid sensitive functional groups showed decomposition when heated with 3,5-dinitrosalicylaldehyde.

[0024] Spiropyrans have been proposed as protecting groups for salicylaldehyde, which can be cleaved using strong oxidizing agents such as potassium permanganate, sodium periodate and ozone [Young Jin Cho et al., Tetrahedron Letters, 2000, 41, 3915-3917]. The oxidizing agents lead to the formation of salicylic acid derivatives and other side products, thus limiting the range of applications. Furthermore, the protecting group cannot be recovered using this method. SUMMARY

[0025] TECHNICAL PROBLEM TO BE SOLVED

[0026] The problems to be solved and deficiencies are set out in the background art. In particular, spiropyrans that can be of interest for application as photoinitiators can not be accessible by the conventional synthesis methods described above. Furthermore, certain methods in the prior art can only provide spiropyrans in low yield, low conversion, high impurities and thus low efficiency. Thus, the availability of spiropyrans that are useful as photoinitiators, especially dual color photoinitiators, is limited, thus hindering and requiring to overcome the provision of new photoinitiators, in particular dual color photoinitiators that are crucial for the development of volumetric printing. Another problem to be solved is to overcome the limitations of efficient functionalization of salicylaldehydes or 2-methyleneindolinones, such that new substitution patterns of salicylaldehydes become accessible for the synthesis of photoinitiators.

[0027] Solution to the problem

[0028] The problems of the prior art are solved by providing, making and using dual color photoinitiators according to the present invention, in particular by the method of manufacturing spiropyrans according to independent claim 1 and the spiropyrans according to independent claim 16, the method of manufacturing spiropyrans according to dependent claim 6 or 12, the method of manufacturing the precursor of formula (2) according to spiropyrans 14, and the method of local polymerization initiation material according to spiropyrans 30 to 32.

[0029] In particular, it can be an object of the present invention to provide a synthesis method forming a spiropyran building block. The provided technology will generally be applicable in the field of spiropyrans and / or dynamic covalent chemistry, in particular in the field of dual color photoinitiators. More specifically, it can be an object of the present invention to overcome the limitations of currently available dual color photoinitiators by providing spiropyrans. More specifically, a method of synthesizing photoinitiators, namely spiropyrans, can be provided and these spiropyrans are not accessible or difficult to obtain in the previously described synthesis routes. The provided photoinitiators induce the curing of photopolymerizable formulations upon irradiation with two different wavelengths and are useful for volumetric printing (dual color volumetric printing).

[0030] A first aspect of the present invention is a method of manufacturing a spiropyran represented by the following formula (1):

[0031] (Formula (1)); The method comprises the following steps: providing a precursor, wherein the precursor is a spiropyran represented by the following formula (2):

[0032] (Formula (2)); providing a reactant, wherein the reactant is an indolium salt represented by the following formula (3):

[0033] (Equation (3)) Or the corresponding 2-methyleneindoline compound; or Salicylaldehyde is represented by the following formula (4):

[0034] (Equation (4)); or

[0035] Spiropyrans represented by the following formula 5:

[0036] (Equation (5)); Optionally, the precursor may be pre-activated; A reaction mixture comprising the precursor or optionally a pre-activated precursor and the reactant are provided to obtain the spiropyran of formula (1); The spiropyran, the precursor, and the reactant are different from each other; If the reactant is an indoleon salt of formula (3), then the obtained spiropyran of formula (1) is represented by the following formula (1A):

[0037] (Equation (1A)), In equation (1A), R" 1 To R" 8 Independently with R" of equation (3) 1 To R" 8 The same, and R' of equation (1A) 9 To R' 13 Independently with R' of equation (2) 9 To R' 13 same; If the reactant is salicylaldehyde of formula (4), then the obtained spiropyran of formula (1) is represented by the following formula (1B):

[0038] (Equation (1B)), In equation (1B), R' 1 To R' 8 Independently with R' of equation (2) 1 To R' 8 The same, and R" of equation (1B) 9 To R" 13 Independently with R" of equation (4) 9 To R" 13 same; If the reactant is spiropyran of formula (5), then the obtained spiropyran of formula (1) is represented by formula (1A), wherein R 1 to R 8 are independently the same as R 1 to R 8 of formula (5), and R 9 to R 13 are independently the same as R 9 to R 13 of formula (2), or then the obtained spiropyran of formula (1) is represented by formula (1B), wherein R 1 to R 8 are independently the same as R 1 to R 8 of formula (2), and R 9 to R 13 are independently the same as R 9 to R 13 of formula (5); wherein X is selected from S, C or N; if X is S, then R 6 , R 7 , R 6 , R 7 , R 6 , R 7 may be absent; if X is N, then R 7 , R 7 , R 7 may be absent, wherein Y is selected from O, S or N; when Y is N, the substituents contain the necessary atoms to form a cyclic structure together with R 13 , the cyclic structure being selected from benzimidazole, indoline, indole, dihydroquinoline and tetrahydroquinoline; wherein Z is selected from N or C; wherein if present, A is selected from O, S or Se; wherein if present, B is selected from H or D; wherein if present, Hal - is a halide anion or an anionic compound; wherein if present, R 1 to R 13 , R 1 to R 13 , and R 1 to R 13 are independently selected from the group consisting of: H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C 20 alkyl; substituted or unsubstituted C3-C 20cycloalkyl; substituted or unsubstituted C6-C 48 aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 alkyl acyl; substituted or unsubstituted C2-C 49 aryl acyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; NH2; substituted or unsubstituted C1-C 20 alkyl ester; substituted or unsubstituted C6-C 48 aryl ester; substituted or unsubstituted C1-C 20 alkyl amide; substituted or unsubstituted C6-C 48 aryl amide; NR'2; SiR'3; -0-SiR'3, where R' is independently selected from substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; substituted or unsubstituted carboxylic acid and its salts; substituted or unsubstituted sulfonic acid and its salts; substituted or unsubstituted sulfonate; substituted or unsubstituted sulfonamide; formyl; ether; sulfide; carbonate; carbonic ester; sulfate; boronic acid; boronic ester; phosphonic acid; phosphonic ester; phosphine; phosphate; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinate; sulfinate; sulfide; thiolester, sulfoxide; sulfone; alkyl sulfone; hydrazide; thioformic acid; ketone; thione; oxime; hydrazine; nitroso; azo; diazonium; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; hydroperoxide; peroxide; acetal; ketal; orthoester; orthocarbonate; ammonium; imine; imide; azide; nitrate; isonitrile; nitrosoxy; substituted or unsubstituted carbamate; substituted or unsubstituted ether; substituted or unsubstituted polyether carbamate; substituted or unsubstituted aryl azo; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; wherein if one or more substituents are present in one or more of R 1 to R 13 are independently selected from the group consisting of: D; halogen; NO2; CN, C2-C 49 alkyl acyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; substituted or unsubstituted C2-C 49Aryl acyl; (meth)acrylate; toluenesulfonyl; sulfonic acid or its salt; carboxylic acid or its salt; boric acid or its salt; phosphonic acid or its salt; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, the two R's can form a ring structure; NH2; and OH; If R exists, 2 To R 5 、R' 2 To R' 5 、R" 2 To R" 5 R 10 To R 13 、R' 10 To R' 13 and R" 10 To R" 13 Two adjacent groups can independently connect with each other to form a fused ring structure; and If R" exists, A To R" B Selected independently from H and D.

[0039] The second aspect of this embodiment is a method for manufacturing a precursor represented by the following formula (2):

[0040] (Equation (2)); Where R' 1 、R' 6 To R' 9 Independently selected from H, D, substituted or unsubstituted C1-C 10 Alkyl, preferably methyl; substituted or unsubstituted C6-C 32 Aryl, preferably phenyl; substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 alkenyl and benzyl; X is C; Z is C; Y is O; R' 2 To R' 5 and R' 10 To R' 13 Independently selected from the following group: H, D, F, Cl, Br, substituted or unsubstituted C1-C 10 Alkyl, substituted or unsubstituted C6-C 32 aryl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C6-C 48Aryloxy group, CF3, CN; wherein two adjacent groups can be linked together to form a fused ring structure, preferably a fused aromatic C6 ring; and substituents of the following formula: , Where R 19 As defined in the description of the invention; Where R' 2 To R' 5 and R' 10 To R' 13 At least one of them is a substituent of the following formula: , The method includes the following steps: Provide reactants, wherein the reactants are spiropyrans represented by the following formula (2A):

[0041] (Equation (2A)); Where R' 2 To R' 5 and R' 10 To R' 13 At least one of them is a halogen atom selected from Cl, Br and I; and the remaining substituents are the same as those in the precursor of formula (2); In metal-halogen exchange reactions, preferably with organolithium reagents or Grignard reagents, the halogen atoms of the reactants react to obtain metal-spiropyran compounds. The metal-spiropyran compound is then reacted with the following Weinreb amide: , Where R 28 and R 29 Selected from substituted or unsubstituted C1-C 10 Alkyl; substituted or unsubstituted C6-C 32 Aryl; substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 Alkenyl, preferably R 28 and R 29 Each is a methyl group. To obtain the precursor of formula (2), wherein the precursor of formula (2) is preferably obtained after posttreatment with an acidic aqueous solution.

[0042] The third aspect of the present invention is a spiropyran represented by the following formula (1):

[0043] (Equation (1)); wherein X is selected from S, C or N; if X is S, then R 6 , R 7 , R' 6 , R' 7 , R" 6 , R" 7 may be absent; if X is N, then R 7 , R' 7 , R" 7 may be absent, wherein Y is selected from O, S or N; when Y is N, the substituents contain the necessary atoms to form a cyclic structure with R 13 together, the cyclic structure being selected from benzimidazole, indoline, indole, dihydroquinoline and tetrahydroquinoline; wherein Z is selected from N or C; wherein R 1 to R 13 are independently selected from the group consisting of H; D; halogen; NO2; CN; OH; SH; CF3; substituted or unsubstituted C1-C 20 alkyl; substituted or unsubstituted C3-C 20 cycloalkyl; substituted or unsubstituted C6-C 48 aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 arylacyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; NH2; substituted or unsubstituted C1-C 20 alkyl ester; substituted or unsubstituted C6-C 48 aryl ester; substituted or unsubstituted C1-C 20 alkylamide; substituted or unsubstituted C6-C 48 aryl amide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48Aryl group, two R's can form a ring structure; substituted or unsubstituted carboxylic acids and their salts; substituted or unsubstituted sulfonic acids and their salts; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; formyl group; ethers, thioethers; carbonates; carbonates; sulfates / esters; boric acid; borate esters; phosphonic acid; phosphonates; phosphine; phosphates / esters; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinates; sulfonates; thiolates, sulfoxides; sulfones; alkyl sulfones; acyl hydrazides; thioaldehydes; ketones; thioketones; oximes; hydrazides Nitrosyl; Azo; Diazo; Diazo salt; Isocyanate; Cyanate; Isocyanate; Thiocyanate; Isothiocyanate; Hydroperoxide; Peroxide; Acetal; Ketal; Orthoester; Orthocarbonate; Ammonium; Imine; Imide; Azide; Nitrate / Ester; Isonitrile; Nitrite group; Substituted or unsubstituted urethane; Substituted or unsubstituted ether; Substituted or unsubstituted polyether urethane; Substituted or unsubstituted aryl azo; Substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 Alkenyl; wherein two adjacent groups can be connected to each other to form a fused ring structure, preferably a fused aromatic C6 ring; Where R 1 To R 13 If one or more of the following substances contain one or more substituents, then the substituents are independently selected from the group consisting of: D; halogens; NO2; CN, C2-C. 49 Alkyl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy group; substituted or unsubstituted C2-C 49 Aryl acyl; (meth)acrylate; toluenesulfonyl; sulfonic acid or its salt; carboxylic acid or its salt; boric acid or its salt; phosphonic acid or its salt; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; NH2; and OH; wherein, if present, R 10 To R 13 and R 2 To R 5 Two adjacent groups can independently connect to each other to form a fused ring structure; and Where R 2 To R 5 and R 10 To R 13 At least one substituent is selected from one of the following groups: chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C49 Aryl acyl; ketone; acyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; or one of the following formulas: , , , , , , and , Where R 14 To R 27 Independently selected from the following groups: H; D; halogen; NO2; CN; OH; SH; CF3; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy groups and NH2; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; substituted or unsubstituted C1-C 20 Alkylamides; substituted or unsubstituted C6-C 48 Arylamides; NR'2, SiR'3, -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C. 20 Alkyl and substituted or unsubstituted C6-C 48aryl, two R' can form a ring structure; substituted or unsubstituted carboxylic acid and its salts; substituted or unsubstituted sulfonic acid and its salts; substituted or unsubstituted sulfonate ester; substituted or unsubstituted sulfonamide; formyl; ether; thioether; carbonate; carbonic ester; sulfate; boronic acid; boronic ester; phosphonic acid; phosphonic ester; phosphine; phosphate; peroxycarbonate; thiocarbonate; sulfinic acid; sulfinic ester; sulfinate; thiol ester, sulfoxide; sulfone; alkyl sulfone; hydrazide; thioaldehyde; ketone; thioketone; oxime; hydrazine; nitroso; azo; diazo; diazonium; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; hydroperoxide; peroxide; acetal; ketal; orthoester; orthocarbonate; ammonium; imine; imide; azide; nitrate; isonitrile; nitrite; substituted or unsubstituted urethane; substituted or unsubstituted ether; substituted or unsubstituted polyether urethane; substituted or unsubstituted aryl azo; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; wherein if one or more substituents are present in one or more of R 14 to R 27 are independently selected from the group consisting of: D; halogen; NO2; CN, C2-C 49 alkylacyl; substituted or unsubstituted C2-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; substituted or unsubstituted C2-C 49 arylacyl; (meth)acrylate; tosyl; sulfonic acid or its salt, carboxylic acid or its salt, boronic acid or its salt, phosphonic acid or its salt, NR'3 + wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; NH2; and OH; and R 15 and R 16 may be linked to each other to form an unsubstituted or substituted ring structure, and wherein R 2 to R 5 and R 10 to R 13 at least one other substituent of R 49 alkylacyl; substituted or unsubstituted C2-C 49Aryl acyl; ketone; acyl group; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; and / or Where R 2 To R 5 and R 10 To R 13 At least one other substituent is selected from the group consisting of: sulfonic acids or their salts; carboxylic acids or their salts; boric acids or their salts; phosphonic acids or their salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl groups, two R's can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; (meth)acrylates; toluenesulfonyl groups; NH2; and OH.

[0044] Furthermore, the spiropyran of the present invention can be a photoinitiator, preferably a bicolor photoinitiator, or can be used directly as a photoinitiator. Other embodiments are defined by the dependent claims.

[0045] In another aspect of the invention, the formulation may contain spiropyran of formula (1), which may be a photoinitiator.

[0046] Another aspect of the invention is a method for locally polymerizing a starting material by using spiropyran according to the invention as a photoinitiator and irradiating the spiropyran with two different wavelengths of light source.

[0047] One aspect of the present invention is a method for locally polymerizing a starting material by two-color photopolymerization, the method comprising: Provided a polymerizable starting material containing photoinitiator molecules, wherein the photoinitiator molecules are spiropyran according to the invention, which are capable of being sequentially photoexcited to a reactive state, wherein the photoinitiator molecules locally trigger the polymerization of the starting material in the reactive state; and By irradiating a local volume with light of a first wavelength and light of a second wavelength different from the first wavelength, the starting material within the local volume is photopolymerized, thereby achieving [the desired effect] within the local volume. the photo-initiator molecule is converted from the initial state, in which the photo-initiator molecule absorbs essentially no light of the second wavelength, to an intermediate state having altered optical properties compared to the initial state, such that the photo-initiator molecule in the intermediate state absorbs light of the second wavelength; and the photo-initiator molecule is converted from the intermediate state to the reactive state due to absorption of light of the second wavelength, thereby locally triggering the polymerization; and / or the photo-initiator molecule is capable of spontaneously converting from the intermediate state to the initial state in a thermal reaction.

[0048] Another aspect of the present application is a method of forming a shaped body by two-color photopolymerization, the method comprising: providing a polymerizable starting material containing photo-initiator molecules, wherein the photo-initiator molecules are spiropyrans as defined according to the present application, which are capable of converting to a reactive state by sequential photoexcitation, in which reactive state the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within a local volume by irradiating light of a first wavelength and light of a second wavelength different from the first wavelength into the local volume, thereby within the local volume, the photo-initiator molecule is converted from the initial state, in which the photo-initiator molecule absorbs essentially no light of the second wavelength, to an intermediate state having altered optical properties compared to the initial state, such that the photo-initiator molecule in the intermediate state absorbs light of the second wavelength; and the photo-initiator molecule is converted from the intermediate state to the reactive state due to absorption of light of the second wavelength, thereby locally triggering the polymerization; and the photo-initiator molecule is capable of spontaneously converting from the intermediate state to the initial state in a thermal reaction.

[0049] Another aspect of the present application is a method of locally polymerizing a starting material and forming a shaped body by two-color photopolymerization, the method comprising the steps of: providing a container at least partially filled with a polymerizable starting material containing photo-initiator molecules, which are capable of converting to a reactive state by sequential photoexcitation, in which reactive state the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within the container by irradiating light of a first wavelength and light of a second wavelength different from the first wavelength into the container, thereby within the container, The photoinitiator molecule, due to absorbing light of the first wavelength, transitions from an initial state where it substantially does not absorb light of the second wavelength to an intermediate state with altered optical properties compared to the initial state, such that the photoinitiator molecule in the intermediate state absorbs light of the second wavelength; and The photoinitiator molecules, by absorbing light of the second wavelength, transition from the intermediate state to the reactive state, thereby locally triggering the polymerization to form the shaped article; and The initial state of the photoinitiator molecules in the photopolymerizable material is less than 5000 Lmol. -1 cm -1 The extinction coefficient.

[0050] In another aspect, the present invention discloses a method for locally polymerizing a starting material and forming a shaped article by dual-color photopolymerization, the method comprising the following steps: A container is provided that is at least partially filled with a polymerizable starting material containing photoinitiator molecules, the photoinitiator molecules being capable of transitioning to a reactive state via sequential photoexcitation, wherein the photoinitiator molecules locally trigger polymerization of the starting material in the reactive state; and By irradiating the container with light of a first wavelength and light of a second wavelength different from the first wavelength, the starting material inside the container is photopolymerized, thereby achieving the desired effect within the container. The photoinitiator molecule, due to absorbing light of the first wavelength, transitions from an initial state where it substantially does not absorb light of the second wavelength to an intermediate state with altered optical properties compared to the initial state, such that the photoinitiator molecule in the intermediate state absorbs light of the second wavelength; and The photoinitiator molecules change from the intermediate state to the reactive state by absorbing the second wavelength of light, thereby locally triggering the polymerization to form a shaped body; The photopolymerizable material described herein has an absorbance in the range of 1 to 0.07 absorbance units at a first wavelength. Detailed Implementation

[0051] 1. General method for the production of spiropyrans of formula (1)

[0052] Spiropyran of formula (1) can be obtained through a reversible exchange reaction.

[0053] Without being bound by any theory, the inventors provide a plausible mechanism for the reversible exchange reaction of the present application that can occur in the reaction mixture: the spiropyran ring opening to form a merocyanine form. Water can undergo a Michael addition with the merocyanine, further reaction to generate free salicylaldehyde and 2-methyleneindoline. 2-Methyleneindoline is a strong nucleophile that can add to another merocyanine in a reversible manner. In a further step, one 2-methyleneindoline is released from the adduct, leaving a new merocyanine that can close to form the corresponding spiropyran. The 2-methyleneindoline thus released can undergo spiropyran condensation with the salicylaldehyde previously released from the spiropyran (shown in the scheme below) or a different salicylaldehyde that has been added to the reaction mixture (not shown in the scheme below). Conversely, the salicylaldehyde released can undergo spiropyran condensation with the 2-methyleneindoline previously released from the spiropyran (shown in the scheme below) or a different 2-methyleneindoline that has been added to the reaction mixture (not shown in the scheme below).

[0054]

[0055] Many nucleophiles can undergo the Michael addition on the merocyanine. In some cases, it can be advantageous to treat the precursor spiropyran with a nucleophile such as methylamine and pre-activate it for the reaction (shown in the scheme below). This activation can lead to the formation of the corresponding imine / immonium / salicylaldehyde and 2-methyleneindoline derivatives and can be more efficient than with water. The corresponding salicylaldehyde and 2-methyleneindoline can be isolated before addition to the reaction, for example by basic extraction.

[0056]

[0057] Another option to accelerate the exchange of two spiropyrans can be to add catalytic amounts of 2-methyleneindoline so that there is always some small excess of nucleophile present. In some embodiments, the efficiency of the reaction can be improved by substituting the indole with an electron-donating moiety and / or the salicylaldehyde with an electron-withdrawing moiety. This substitution pattern can facilitate the ring opening to a merocyanine and the attack of the 2-methyleneindoline on the merocyanine. In another embodiment, the efficiency of the reaction can be improved by substituting R 8 ' to the precursor of formula (2) with an electron-donating moiety such as a methyl group. This substitution can shift the equilibrium towards the product side. Such substituents can affect the basicity and nucleophilicity of the corresponding 2-methyleneindoline derivative.

[0058] Thus, a mixture of two or more spiropyrans can exchange their respective components originating from 2-methyleneindolin and salicylaldehyde. The spiropyrans can be dissolved in a suitable solvent and heated until equilibrium is reached. Starting with two spiropyrans having different 2-methyleneindolin and salicylaldehyde components, when thermodynamic equilibrium is reached, four different spiropyrans can be found in the mixture. The number of possible spiropyrans can increase according to the possible combinations. According to the number of starting spiropyrans originating from different 2-methyleneindolin I and different salicylaldehyde S, the maximum number of different derivatives in the mixture P can be according to formula P = S I deduce the maximum number of different derivatives in the mixture P.

[0059] As mentioned above, in one aspect, a method of manufacturing a spiropyrane represented by the following formula (1) is provided:

[0060] (formula (1)).

[0061] The method comprises the steps of: providing a precursor, wherein the precursor is a spiropyrane represented by the following formula (2):

[0062] (formula (2)); providing a reactant, wherein the reactant is an indolenium salt represented by the following formula (3):

[0063] (formula (3)), or a corresponding 2-methyleneindolin compound; or as an alternative a salicylaldehyde represented by the following formula (4):

[0064] (formula (4)); or as another alternative

[0065] a spiropyrane represented by the following formula 5:

[0066] (formula (5)).

[0067] Optionally, the precursor is pre-activated. A reaction mixture comprising the precursor or optionally the pre-activated precursor and the reactant is provided to obtain the spiropyrane of formula (1). Thereby, the spiropyrane, the precursor and the reactant are different from each other. If the reactant is an indolenium salt of formula (3), the obtained spiropyrane of formula (1) is represented by the following formula (1A):

[0068] (Equation (1A)), In equation (1A), R" 1 To R" 8 Independently with R" of equation (3) 1 To R" 8 The same, and R' of equation (1A) 9 To R' 13 Independently with R' of equation (2) 9 To R' 13 same; If the reactant is salicylaldehyde of formula (4), then the obtained spiropyran of formula (1) is represented by the following formula (1B):

[0069] (Equation (1B)), In equation (1B), R' 1 To R' 8 Independently with R' of equation (2) 1 To R' 8 The same, and R" of equation (1B) 9 To R" 13 Independently with R" of equation (4) 9 To R" 13 same.

[0070] In another aspect of the invention, the invention solves the problem of providing methylene indoline.

[0071] Those skilled in the art will understand that the byproducts of the spiropyran of formula (2) and the methylene indoline of formula (3) can be the methylene indoline of formula (3B):

[0072] (Formula 3B).

[0073] Among them, R' 1 、R' 2 、R' 3 、R' 4 、R' 5 、R' 6 、R' 7 and R' 8 The substituents and X are the same as those in formula (2) from which the methylene indoline of formula (3B) originates. The methylene indoline of formula (3B) can be protonated to the corresponding indoline salt. In a preferred embodiment of the methylene indoline of formula (3B), X is C and / or R'. AH. One skilled in the art will recognize that the method of the present application for making spiropyrans can also be used to provide methyleneindolines, such as methyleneindolines of Formula (3B), which can be difficult to obtain or can be impossible to obtain by alternative conventional synthetic routes. Methyleneindolines of Formula (3B) can be used as precursors for different reactions, such as for the synthesis of another spiropyran.

[0074] In another aspect of the present application, the present application addresses the problem of providing salicylaldehydes. The salicylaldehydes can contain substituents and / or patterns of substitution that are not obtainable by conventional synthetic routes.

[0075] One skilled in the art will recognize that the by-products of the spiropyrans of Formula (2) and the salicylaldehydes of Formula (4) can be salicylaldehydes of Formula (4B) below:

[0076] (Formula (4B)).

[0077] The salicylaldehydes of Formula (4B) can be by-products that can be obtained as by-products of the spiropyrans of Formula (2) that can be pre-activated with nucleophiles, such as amines, as further described below.

[0078] wherein R' 9 , R' 10 , R' 11 , R' 12 and R' 13 are substituents as in Formula (2) from which the salicylaldehydes of Formula (4B) are derived. In one preferred embodiment of the salicylaldehydes of Formula (4B), Y is O, Z is C, and / or R' 9 is H. The salicylaldehydes of Formula (4B) can be compounds in which at least one of the substituents R' 10 , R' 11 , R' 12 and R' 13 cannot be obtained directly from a salicylaldehyde. Thus, one skilled in the art will recognize that the method of the present application for making spiropyrans can also be used to provide salicylaldehydes, such as salicylaldehydes of Formula (4B), which can be difficult to obtain or can be impossible to obtain by alternative conventional synthetic routes.

[0079] Such salicylaldehydes can be obtained by utilizing the spiropyrans of Formula (2) as protecting groups for the salicylaldehydes of Formula (4B) by which the substituents R' 10 , R' 11 , R' 12 and R' 13Subsequently, the desired salicylaldehyde of formula (4B) can be "deprotected" by using the method for manufacturing a spiropyran of formula (IB) by reacting a spiropyran of formula (2) with a nucleophile (e.g. an amine as further specified below under pre-activation of the precursor of formula (2)) or a salicylaldehyde of formula (4). The salicylaldehyde of formula (4B) can be used as a precursor for different reactions, e.g. for the synthesis of another spiropyran.

[0080] If the reactant is a spiropyran of formula (5), the obtained spiropyran of formula (1) is represented by formula (1A), wherein R 1 to R 8 are independently the same as R 1 to R 8 of formula (5), and R 9 to R 13 are independently the same as R 9 to R 13 of formula (2), or

[0081] the obtained spiropyran of formula (1) is represented by formula (IB), wherein R 1 to R 8 are independently the same as R 1 to R 8 of formula (2), and R 9 to R 13 are independently the same as R 9 to R 13 of formula (5); X is selected from S, C or N; if X is S, then R 6 , R 7 , R 6 , R 7 , R 6 , R 7 may be absent; if X is N, then R 7 , R 7 , R 7 may be absent; preferably X is C.

[0082] Y is selected from O, S or N; when Y is N, the substituents contain the atoms necessary to form a cyclic structure together with R 13 , said cyclic structure being selected from benzimidazole, indoline, indole, dihydroquinoline and tetrahydroquinoline, preferably Y is O.

[0083] Z is selected from N or C, preferably Z is C.

[0084] A, if present, is selected from O, S or Se, preferably A is O.

[0085] B is selected from H or D, if present, preferably B is H.

[0086] Hal - is a halogen anion or an anionic compound, if present, preferably Hal - is Cl - , Br - , I - , more preferably Hal - is I - .

[0087] R 1 to R 13 , R' 1 to R' 13 , and R" 1 to R" 13 are independently selected from the group consisting of H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C 20 alkyl; substituted or unsubstituted C3-C 20 cycloalkyl; substituted or unsubstituted C6-C 48 aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 alkenyl; substituted or unsubstituted C2-C 49 alkynyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; NH2; substituted or unsubstituted C1-C 20 alkyl ester; substituted or unsubstituted C6-C 48 aryl ester; substituted or unsubstituted C1-C 20 alkyl amide; substituted or unsubstituted C6-C 48 aryl amide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48aryl, two R' can form a ring structure; substituted or unsubstituted carboxylic acid and its salt; substituted or unsubstituted sulfonic acid and its salt; substituted or unsubstituted sulfonate; substituted or unsubstituted sulfonamide; formyl; ether; thioether; carbonate; carbonic ester; sulfate; boronic acid; boronic ester; phosphonic acid; phosphonic ester; phosphine; phosphate; peroxycarbonate; thiocarbonate; sulfinic acid; sulfinic ester; sulfinate; thiol ester, sulfoxide; sulfone; alkyl sulfone; hydrazide; thioaldehyde; ketone; thioketone; oxime; hydrazine; nitroso; azo; diazo; diazonium; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; hydroperoxide; peroxide; acetal; ketal; orthoester; orthocarbonate; ammonium; imine; imide; azide; nitrate; isonitrile; nitrite; substituted or unsubstituted urethane; substituted or unsubstituted ether; substituted or unsubstituted polyether urethane; substituted or unsubstituted aryl azo; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; if one or more substituents in one or more of R 1 to R 13 are present, they are independently selected from the group consisting of D; halogen; NO2; CN, C2-C 49 alkylacyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; substituted or unsubstituted C2-C 49 arylacyl; (meth)acrylate; tosyl; sulfonic acid or its salt; carboxylic acid or its salt; boronic acid or its salt; phosphonic acid or its salt; NR'3 + wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; NH2; and OH.

[0088] if one or more substituents in one or more of R 2 to R 5 , R' 2 to R' 5 , R" 2 to R" 5 , R 10 to R 13 ; R' 10 to R' 13 and R" 10 to R" 13 are present, they can independently be linked to each other to form a fused ring structure; if R" A to R" B are present, they can independently be selected from H and D.

[0089] Preferably, at least one of R 2 to R 5 and R 10 to R 13 is a substituent selected from the group consisting of chloro; bromo; iodo; formyl; carbonate; carbonic acid ester; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 arylacyl; ketone; acyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkylsulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and tosyl; or one of the following formulae: , , , , , , and .

[0090] More preferably, at least one of R 10 and R 12 to R 13 is a substituent selected from the group consisting of chloro; bromo; iodo; formyl; carbonate; carbonic acid ester; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 arylacyl; ketone; acyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkylsulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and tosyl; or one of the following formulae: , , , , , , and ; wherein R 14 to R 27 are as defined above.

[0091] More preferably, at least one of R 2 to R 5 and at least one of R 10 to R 13 , as preferred R 10 and R 12 to R 13Substituents selected from the group consisting of: carbonyl; chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; or one of the following formulas: , , , , , , and This results in the spiropyran of formula (1) containing at least two of these substituents.

[0092] Spiropyrans containing one of the aforementioned substituents can be advantageous as photoinitiators, preferably bicolor photoinitiators. On the other hand, spiropyrans containing one of these substituents can be obtained by limited manufacturing methods or not at all, because organometallic reagents, such as organolithium reagents, may instead attack the carbonyl group of the substituent, leading to undesirable byproducts. The method for manufacturing spiropyrans of formula (1) avoids the use of organometallic reagents in the presence of a sensitive moiety, and therefore surprisingly, the method is able to provide spiropyrans containing the aforementioned substituents (i.e., the carbonyl moiety) with higher efficiency.

[0093] R 14 To R 27 It can be independently selected from H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C. 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 aryloxy group; NH2; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; substituted or unsubstituted C1-C 20 Alkylamides; substituted or unsubstituted C6-C 48 Arylamide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; substituted or unsubstituted carboxylic acid and its salts; substituted or unsubstituted sulfonic acid and its salts; substituted or unsubstituted sulfonate; substituted or unsubstituted sulfonamide; formyl; ether; thioether; carbonate; carbonic ester; sulfate; boronic acid; boronic ester; phosphonic acid; phosphonic ester; phosphine; phosphate; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinic ester; sulfinate; thiol ester, sulfoxide; sulfone; alkyl sulfone; hydrazide; thioaldehyde; ketone; thioketone; oxime; hydrazine; nitroso; azo; diazo; diazoate; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; hydroperoxide; peroxide; acetal; ketal; orthoester; orthocarbonate; ammonium; imine; imide; azide; nitrate; isonitrile; nitrite; substituted or unsubstituted carbamate; substituted or unsubstituted ether; substituted or unsubstituted polyether carbamate; substituted or unsubstituted aryl azo; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; wherein if R 14 to R 27 one or more substituents present in one or more of R 49 alkyl acyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; substituted or unsubstituted C2-C 49 aryl acyl; (meth)acrylate; tosyl; sulfonic acid or its salt; carboxylic acid or its salt; boronic acid or its salt; phosphonic acid or its salt; NR'3 + wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; NH2; and OH; and R 15 and R 16 may be linked to each other to form an unsubstituted or substituted ring structure.

[0094] Preferably, R 2 to R 5 and R 10 to R 13 at least one of R 49 alkyl acyl; substituted or unsubstituted C2-C 49Aryl acyl; ketone; acyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; dicyanovinylene; and toluenesulfonyl. More preferably, R in formula (1) 2 To R 5 and R 10 To R 13 At least one of them is a substituent selected from chlorine, bromine, and iodine, preferably bromine or iodine.

[0095] As outlined in the background section, halides such as chlorine, bromine, or iodine can be converted to carbonyl functional groups in subsequent reactions. Halides can be present at each position of salicylaldehyde in formula (4) and at each position of 2-methyleneindoline in formula (3), thus allowing conversion to carbonyl groups at each position. Consequently, bromides can also be introduced by reacting N-bromosuccinimide with salicylaldehyde containing electron-withdrawing groups (such as trifluoromethyl). Therefore, halogenated spiropyrans can be prepared as precursors of carbonyl-substituted spiropyrans. For example, one way to introduce a carbonyl group is by using n-butyllithium to perform a metal halide exchange of bromine on the spiropyran and reacting the resulting organolithium with a venerealamide. The novel carbonyl-containing spiropyrans can undergo the exchange reactions disclosed in this invention, thus allowing substitution modes that are not obtainable by conventional methods of the prior art.

[0096] More preferably, R in equation (1) 2 To R 5 and R 10 To R 13 At least one, preferably at least two, of the following are selected from CN, F, Cl, OCF3, NO2, ester group, ketone, formyl group, acyl group, SO2R (such as SO2CF3, SO2Me, SO2Ph or SO2NH2), SF5, NR3 + Substituents of pyridinium, halogens, and fluorinated alkyl or aryl groups (such as CF3). Even more preferably, the substituents are selected from acyl groups, substituted or unsubstituted benzoyl groups, CN, F, Cl, OCF3, NO2, and CF3, with acyl groups, substituted or unsubstituted benzoyl groups, and CF3 being the most preferred.

[0097] In one implementation, R 2 To R 5 Independently selected from H and electron-withdrawing groups, and R 10 To R 13 One of them is selected from unsubstituted or substituted C6-C. 49 Aryl acyl; or unsubstituted or substituted C2-C 49Alkyl acyl group. Typical electron-withdrawing groups can be CN, F, Cl, OCF3, NO2, ester, formyl, acetyl, benzoyl, substituted benzoyl, acyl, SO2R (such as SO2CF3, SO2Me, SO2Ph or SO2NH2), SF5, NR3 + , pyridinium, halogens and fluorinated alkyl or aryl (such as CF3).

[0098] Surprisingly, it has been found that electron-withdrawing groups in spiropyrans of formula (1) can be uncoupled. Therefore, if spiropyrans of formula (1) are used as photoinitiators, preferably bicolor photoinitiators, ultraviolet light is absorbed, and the spiropyrans of formula (1) undergo ring-opening to form the corresponding monotonic cyanide. The probability of spiropyran ring-opening to form the corresponding monotonic cyanide depends on R in formula (1). 2 To R 5 and R 10 To R 13 The more electron-withdrawing groups the substituent has, the more electrons are provided. Therefore, in a preferred embodiment, R 2 To R 5 and R 10 To R 13 Multiple electron-withdrawing groups, such as two or more CF3 or other electron-withdrawing groups, replace R 2 To R 5 and R 10 To R 13 Above. Unbound by any theory, in the mythocyanin form, the acceptor is in a conjugated state, thereby reducing the HOMO and LUMO of mythocyanins. When electron-deficient mythocyanins absorb visible light, they form an excited state with strong oxidizing properties and a long lifetime.

[0099] In one implementation, the R of the spiropyran of formula (2) 2 'To R 5 At least one of the components is independently selected from electron-donating groups. Typical electron-donating groups can be SH, SR, OH, OR, NH2, NHR, and NR2. This substitution mode may promote the attack of cyanine on cyanine by ring-opening and 2-methyleneindoline. Preferably, R 4 It is OR, more preferably methoxy. In another embodiment, R 1 Can be selected from C1-C 20 Alkyl and C6-C 48 Aryl, or C1-C8 alkyl and C6-C 18 aryl, or C1-C4 alkyl and C6-C 12 Aryl, preferably methyl, benzyl and phenyl.

[0100] In one embodiment, the photoinitiator of formula (1) can be linked to a polymerizable group. The polymerizable group can be selected from the group consisting of (meth)acrylate, acrylamide, vinyl ether and vinyl ester, preferably (meth)acrylate, by R 1 to any one of R 13 .

[0101] In another embodiment, at least one of R 1 to R 13 in the photoinitiator of formula (1) can comprise at least one structural element selected from thioxanthone, acenaphthene-1,2-dione, thiochroman-4-one, 9-fluorenone, anthraquinone, benzanthrone, 9,10-phenanthrenequinone, xanthone, 1,3-indanedione, chromone, 1,4-naphthoquinone, coumarin, benzil, benzophenone and phenylacetophenone.

[0102] In another embodiment, at least one of R 1 to R 13 in the photoinitiator of formula (1) can be a substituted or unsubstituted C6-C 48 aryl group or a substituted or unsubstituted C1-C 20 alkyl group, wherein the substituents comprise at least one structural element selected from thioxanthone, acenaphthene-1,2-dione, thiochroman-4-one, 9-fluorenone, anthraquinone, benzanthrone, 9,10-phenanthrenequinone, xanthone, 1,3-indanedione, chromone, 1,4-naphthoquinone, coumarin, benzil, benzophenone and phenylacetophenone.

[0103] In another embodiment, two or more spiropyrans of formula (1) can be linked to each other by a linking group. The chemical bond to the linking group can be established independently by any one of R 1 to R 13 , preferably by R 1 .

[0104] Preferably, at least one of R 2 to R 5 and R 10 to R 13 in formula (1) is a substituent selected from the group consisting of sulfonic acid or a salt thereof; carboxylic acid or a salt thereof; boronic acid or a salt thereof; phosphonic acid or a salt thereof; NR'3 + wherein R' is independently selected from the group consisting of H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48aryl, two R' can form a ring structure; substituted or unsubstituted sulfonate; substituted or unsubstituted sulfonamide; phosphonate; phosphine; phosphate; sulfinic acid; sulfite; sulfinate; sulfoxide; sulfone; alkyl sulfone; oxime; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; ammonium; substituted or unsubstituted carbamate; (meth)acrylate; tosyl; NH2, and OH.

[0105] Preferably, R 6 and R 7 are independently substituted or unsubstituted C1-C 20 alkyl. Two adjacent groups of R 6 and R 7 may be linked to each other to form a fused cycloalkyl ring structure, preferably a fused C4-C8 cycloalkyl, even more preferably cyclohexyl or cyclopentyl. Preferably, the substituted C1-C 20 alkyl can be substituted with at least one substituent selected from terminal sulfonic acid or salt thereof, carboxylic acid or salt thereof, and ammonium salt, or cyclized to form a C4-C8 cycloalkyl ring.

[0106] Preferably, R 1 is selected from H, D, substituted or unsubstituted C1-C6 alkyl, -CH2-CH2-OH, -CH2-COOH, -CH2-CH2-COOH, -CH2-CH2-CH2-NMe3 + , -CH2-CH2-CH2-SO3 - , phenyl, and benzyl. More preferably, R 1 is methyl, -CH2-CH2-OH, phenyl or benzyl, -CH2-COOH, -CH2-CH2-COOH, -CH2-CH2-CH2-NMe3 + , and -CH2-CH2-CH2-SO3 - .

[0107] Preferably, R 8 may be selected from H, D, substituted or unsubstituted C1-C6 alkyl, and substituted or unsubstituted phenyl. More preferably, R 8 is H or methyl.

[0108] Preferably, R 2 to R 5 may be independently selected from H, D, substituted or unsubstituted C1-C6 alkyl, carboxylic acid and salt thereof, sulfonic acid and salt thereof, phosphonic acid and salt thereof, fluorine, bromine, chlorine, iodine, substituted or unsubstituted C2-C 49 alkyl acyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C2-C 49arylacyl, CN, N02, aldehyde, ketone, sulfone, sulfonamide, S02Me, S02Ph, S02NH2, CF3.

[0109] More preferably, at least one of R 2 , R 3 , R 5 is a substituted or unsubstituted C2-C 49 alkylacyl; a substituted or unsubstituted C2-C 49 arylacyl, CN, aldehyde, or ketone.

[0110] More preferably, at least one of R 2 to R 5 is a substituted C2-C 49 alkylacyl; a substituted C2-C 49 arylacyl, wherein the substituents are selected from the group of electron- withdrawing groups.

[0111] More preferably, at least one of R 10 to R 13 may be independently selected from H, D, substituted or unsubstituted C1-C6alkyl, carboxylic acid and its salts, sulfonic acid and its salts, phosphonic acid and its salts, fluorine, bromine, chlorine, iodine, substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C2-C 49 arylacyl, CN, N02, aldehyde, ketone, sulfone, sulfonamide, S02Me, S02Ph, S02NH2, CF3, OCF3.

[0112] More preferably, at least one of R 10 , R 11 , R 13 is a substituted or unsubstituted C2-C 49 alkylacyl; a substituted or unsubstituted C2-C 49 arylacyl, CN, aldehyde, or ketone.

[0113] In another embodiment, R 11 may be selected from CF3, H, D, substituted or unsubstituted alkoxy, substituted or unsubstituted alkyl, more preferably methyl, tert-butyl, methoxy.

[0114] In a preferred embodiment, R 11 may be selected from H, D, substituted or unsubstituted alkoxy, substituted or unsubstituted alkyl, more preferably methyl, tert-butyl, or methoxy. The introduction of R 11 as one of the selected substituents is advantageous in providing improved bis-colour photoinitiators.

[0115] More preferably, at least one of R 10 to R 13substituted C2-C 49 alkyl acyl; substituted C2-C 49 aryl acyl, wherein the substituents are selected from the group consisting of electron withdrawing groups.

[0116] In one embodiment, R 12 and R 13 , or R 11 and R 12 may be linked together to form a fused 5- or 6-membered ring. Preferably, the fused 5- or 6-membered ring can contain at least one heteroatom. The heteroatom can be selected from the group consisting of O, S and N. The formed fused 5- or 6-membered ring can be a derivative of a flavone, a xanthone, a thioxanthone, a coumarin or a naphthoquinone. Even more preferably, the spiropyran of formula (1) is selected from the group consisting of: .

[0117] Preferably, R 14 may be selected from the group consisting of H, methyl, halogen, more preferably, R 14 , R 15 and R 16 may be independently selected from the group consisting of H, methyl, halogen. More preferably, R 14 , R 15 and R 16 are chloro.

[0118] Preferably, R 14 , R 15 and R 16 may be independently selected from the group consisting of H, D, CN, substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl, more preferably, R 14 , R 15 and R 16 may be selected from the group consisting of methyl, phenyl or substituted phenyl.

[0119] In another preferred embodiment, R 14 may be NR'2, wherein R' can be independently selected from the group consisting of H, D, substituted or unsubstituted C1-C 10 alkyl and substituted or unsubstituted C6-C 32 aryl, and both R' can form a ring structure; R 15 and R 16 may be independently selected from the group consisting of H, D, CN, substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C32 aryl; substituted or unsubstituted C2-C 28 heteroaryl. More preferably, R 14 may be NR'2, where R' can be independently selected from substituted or unsubstituted C1-C 10 alkyl, both R' can form a ring structure; R 15 and R 16 may be independently selected from substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl. Most preferably, R 14 may be NR'2, where R' can be methyl, ethyl, or both R' constitute morpholine; R 15 and R 16 are independently selected from methyl, ethyl and benzyl.

[0120] In another preferred embodiment, R 14 may be OR', where R' is selected from H, D, substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl, SiR"3, where R" is independently selected from substituted or unsubstituted C1-C 10 alkyl and substituted or unsubstituted C6-C 32 aryl, R 15 and R 16 may be independently selected from H, D, CN, substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl. More preferably, R 14 may be OR', where R' is independently selected from H, D, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, SiR"3, where R" is independently selected from substituted or unsubstituted C1-C 10 alkyl and substituted or unsubstituted C6-C 32 aryl. R 15 and R 16 may be independently selected from substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C32 aryl. Most preferably, R 14 is OR', wherein R' is methyl, ethyl, benzyl or trimethylsilyl; and R 15 and R 16 are independently selected from methyl, ethyl, phenyl and benzyl.

[0121] In another preferred embodiment, R 14 and R 15 may be OR', wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl, R 16 may be selected from H, D, CN, substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl. More preferably, R 14 and R 15 may be OR', wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl; and R 16 may be selected from substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl. Most preferably, R 14 and R 15 may be OR', wherein R' is H, methyl, ethyl or benzyl; and R 16 may be selected from methyl, ethyl, phenyl and benzyl.

[0122] Preferably, R 17 may be selected from substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl, substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; OR', wherein R' is selected from H, D, substituted or unsubstituted C1-C 10alkyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl, which substituents can contain atoms necessary to form a ring structure with one of R 5 to R 8 or R 10 to R 13 atoms necessary to form a ring structure with one of R 17 is selected from substituted or unsubstituted C1-C 10 alkyl; substituted or unsubstituted C6-C 32 aryl; OR', wherein R' is selected from H, substituted or unsubstituted C1-C 10 alkyl. Most preferably, R 17 may be methyl, ethyl, phenyl, methoxy or ethoxy.

[0123] Preferably, R 18 may be O or NR', wherein R' is selected from substituted or unsubstituted C1-C 20 alkyl ester; substituted or unsubstituted C6-C 48 aryl ester. More preferably, R 18 may be O or NR', wherein R' is substituted or unsubstituted C6-C 48 aryl ester. Most preferably, R 18 may be O or NR', wherein R' is phenyl ester or cresyl ester.

[0124] Preferably, R 14 to R 27 , preferably R 19 , can contain atoms necessary to form a ring structure with one of R 5 to R 8 or R 10 to R 13 atoms necessary to form a ring structure with one of R

[0125] Preferably, R 19 may be selected from substituted or unsubstituted C1-C 10 alkyl, preferably methyl or ethyl; substituted or unsubstituted C3-C 10 cycloalkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 28 heteroaryl, substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl, which substituents can contain atoms necessary to form a ring structure with one of R 5 to R 8 or R 10 to R13 one of R 5 to R 8 or R 10 to R 13 one of R 19 may form a ring structure together with the atoms necessary for the formation of the ring structure, thereby forming anthracene, thianthone, fluorenone, acenaphthene-1,2-dione, thiochroman-4-one, 9-fluorenone, anthraquinone, benzanthrone, 9,10-phenanthrenequinone, xanthone, 1,3-indanedione, chromone, 1,4-naphthoquinone, coumarin, more preferably R 19 If the selected substituent of R 1 or R 1 may be the same as R 1 , R 2 or R 2 may be the same as R 2 , R 3 or R 3 may be the same as R 3 , R 4 or R 4 may be the same as R 4 , R 5 or R 5 may be the same as R 5 , R 6 or R 6 may be the same as R 6 , R 7 or R 7 may be the same as R 7 , R 8 or R 8 may be the same as R 8 , R 9 or R 9 may be the same as R 9 , R 10 or R 10 may be the same as R

[0126] In a preferred embodiment, the following formula: may be an a-amino acyl group, an a-N,N-dialkylamino-acyl group, an a-hydroxy acyl group or an a-alkoxy acyl group.

[0127] R 1 or R 1 may be the same as R 1 , R 2 or R 2 may be the same as R 2 , R 3 or R 3 may be the same as R 3 , R 4 or R 4 may be the same as R 4 , R 5 or R 5 may be the same as R 5 , R 6 or R 6 may be the same as R 6 , R 7 or R 7 may be the same as R 7 , R 8 or R 8 may be the same as R 8 , R 9 or R 9 may be the same as R 9 , R 10 or R 10 may be the same as RR 10 may be the same as R 11 or R 11 may be the same as R 11 may be the same as R 12 or R 12 may be the same as R 12 may be the same as R 13 or R 13 may be the same as R 13 .

[0128] Here, halogen can be fluorine, chlorine, bromine or iodine.

[0129] Here, alkyl, alkenyl and alkynyl can be cyclic, straight-chained or branched.

[0130] Here, alkyl acyl has the following formula: , and aryl acyl has the following formula: , where the wavy line indicates the bond of the acyl group to the structure of formula (1).

[0131] In the case where one (or more) of the groups R 1 to R 13 is (are) selected to be an amide, the bond can be formed through N as well as through CO.

[0132] In the case where one (or more) of the groups R 1 to R 13 is (are) selected to be an ester, the bond can be formed through O as well as through CO.

[0133] In another embodiment, it is provided that R 3 to R 8 and R 10 to R 13 are independently selected from H and an electron-withdrawing group.

[0134] It can be beneficial that spirofluorophores of formula (1) containing one or more of the above-mentioned preferred substituents are useful as photoinitiators, preferably as dual color photoinitiators, or as intermediates for obtaining photoinitiators. On the other hand, spirofluorophores containing one of these substituents can be obtainable by limited manufacturing processes or not at all, because organic metal reagents, such as organolithium reagents, which can be used in conventional synthetic routes, can instead undergo metal-substituent exchange, such as metal-halogen exchange, leading to the production of undesired side products. However, by conventional methods of the prior art, other undesired side reactions can also occur with the above-mentioned moieties. The method of the present invention for manufacturing spirofluorophores of formula (1) can avoid the use of organic metal reagents and other harsh reagents in the presence of sensitive functional groups, and therefore, surprisingly, the method can provide spirofluorophores containing the above-mentioned substituents with higher efficiency, or can be obtainable for the first time.

[0135] Without being bound by any theory, the skilled person can know that, although formylation of 4-hydroxybenzophenone in a Reimer-Tiemann reaction or a Casiraghi reaction can lead to the corresponding 2-hydroxy-5-benzoyl-benzaldehyde, similar reactions with other hydroxybenzophenone derivatives, such as 2-hydroxybenzophenone or 3-hydroxybenzophenone, are practically not possible. The method of the present invention for manufacturing spirofluorophores of formula (1) can circumvent the formylation of hydroxybenzophenone derivatives, and therefore, surprisingly, the method can provide spirofluorophores containing a carbonyl substituent in a position other than R 11

[0136] Although electron-rich acid anhydrides can be used for the Friedel-Crafts acylation in the 5-position of 2-hydroxybenzaldehyde, this is not possible for other positions or electron-deficient acid chlorides or acid anhydrides. A further limitation is that salicylaldehydes functionalized with electron-withdrawing groups are not active enough for Friedel-Crafts acylation, and therefore it is difficult to introduce more than one electron-withdrawing group. In one aspect of the present invention, the above-mentioned method can be used to obtain spirofluorophores of formula (1) having more than one electron-withdrawing group, which can additionally contain at least one carbonyl group.

[0137] ​To this end, a method can be one in which halides such as chlorine, bromine or iodine are converted into carbonyl functions in subsequent reactions. The halides can be present in each position of the salicylaldehyde of formula (4) and in each position of the 2-methyleneindoline of formula (3), allowing conversion into carbonyl groups in each position of the spiropyran. Thereby, bromides can also be introduced by reaction of N-bromosuccinimide with salicylaldehydes bearing electron withdrawing groups such as trifluoromethyl groups. Thus, halogenated spiropyrans can be prepared as precursors of carbonyl substituted spiropyrans. The new carbonyl containing spiropyrans can undergo exchange reactions as disclosed in the present invention, allowing substitution patterns which are not accessible by conventional methods of the prior art. This method is equally applicable to introduce electron deficient carbonyl groups, or to introduce carbonyl groups which are difficult to obtain by direct functionalization of salicylaldehydes or 2-methyleneindolines. Thus, the method can introduce two or more carbonyl functions when other electron withdrawing substituents are already present in the precursor of formula (2) or in any of the reactants of formula (3), formula (4) or formula (5). Furthermore, the method of the present invention allows the simultaneous introduction of two identical carbonyl groups when the spiropyran is substituted by halides on the indole and salicylal parts of the molecule, respectively. In this case, two equivalents of n-butyllithium and the corresponding succinamide can be used.

[0138] The advantage of this method is the simple simultaneous introduction of the necessary functional carbonyl groups, resulting in a dual color photoinitiator which surprisingly improves the absorption spectrum, switching and initiation efficiency. While methods according to the prior art usually only allow the simultaneous introduction of electron rich carbonyl groups (such as acyl or benzoyl) at the R 4 and R 11 positions, provided that no other electron withdrawing groups are present in the molecule. The newly described method is not limited in terms of position selection, electronic nature of the carbonyl substituents or other electron withdrawing substituents already present, especially when R 4 or R 11 are H. By installing multiple functions in one reaction, a short synthesis method is provided for complex and highly functionalized spiropyrans. When other functions are introduced beforehand which are compatible with the reaction conditions to achieve the groups, such as CF3, methyl, methoxy, etc., it is possible to introduce three or more functions in a surprisingly short synthesis route. These spiropyrans can be more suitable as dual color photoinitiators than the dual color initiators described in the prior art.

[0139] The present application can also be advantageous for introducing functional groups on the spiropyran, 2-methyleneindolinine or salicylaldehyde which interfere with the reaction conditions for introducing the carbonyl functionality. This can be of some importance for the synthesis of spiropyrans which are functionalized with at least two different carbonyl groups or at least one carbonyl group and at least one interfering substituent. This includes substituents which have insufficient solubility in solvents such as tetrahydrofuran, such as charged groups, such as sulfonates, sulfonic acids, carboxylates, carboxylic acids, quaternary ammonium salts, phenoxy anions, hydroxyl groups, phosphonic acids and phosphonates. This also includes halides such as Cl, Br and I which are themselves capable of undergoing metal-halogen exchange and functional groups which are capable of reacting with organometallic species such as n-butyllithium, including but not limited to ketones, aldehydes, nitriles, esters, carboxamides, carbonates, cyanates, isocyanates, nitro groups, carbamates, oximes, sulfonyl groups, methyl sulfones, alkyl sulfones and phosphine oxides. This also includes aromatic systems which are capable of being deprotonated by n-butyllithium due to having very electron-withdrawing substituents such as two trifluoromethyl groups.

[0140] The present application can also be advantageous for introducing different carbonyl groups on either side of the spiropyran motif and have flexibility in position selection, thereby improving the properties in terms of dual color photoinitiating performance.

[0141] 1.1. Precursor, spiropyrans of formula (2)

[0142] R' of the precursor of formula (2) 2 to R' 5 and R' 10 to R' 13 at least one of R' 10 to R' 13 at least one of R' 10 , R' 12 and R' 13 may be a substituent selected from the group consisting of chloro; bromo; iodo; formyl; carbonate; carbonate ester; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 arylacyl; ketone; acyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and tosyl; or one of the following formulae: , , , , , , and ; wherein R 14 to R 27 are as defined above.

[0143] Preferably, if R' 2 To R' 5 If at least one of the components is replaced by one of the aforementioned substituents, then R' 10 To R' 13 It may also be replaced by one of the above-mentioned substituents, wherein the substituent is preferably an electron-withdrawing group, more preferably CF3.

[0144] Preferably, R 8 'Selected from H, D or C1-C8 alkyl, preferably methyl.'

[0145] Therefore, spiropyrans of formula (1) containing at least one of the aforementioned substituents can be efficiently obtained from a precursor containing one of the aforementioned substituents. Surprisingly, such spiropyrans of formula (1) may not be obtainable by the conventional methods reported in the prior art.

[0146] The spiropyran precursor of formula (2) can be provided in the reaction mixture in 1.0 equivalents.

[0147] The precursor can be preactivated with a nucleophile as disclosed above. Preferably, the nucleophile can be an amine base, more preferably an amine base, to obtain the preactivated precursor before providing the reaction mixture. In one embodiment, the precursor can be preactivated in situ in the reaction mixture by adding a catalytic amount of an amine base. The catalytic amount of the amine base relative to the amount of the precursor can be 0.02 to 0.2 equivalents, preferably 0.5 to 0.15 equivalents, and most preferably 0.1 equivalents. The formation of the preactivated precursor can improve the formation of the spiropyran of formula (1).

[0148] In another embodiment, the precursor may be pre-activated by reacting with water, an amine base, and / or an acid prior to addition to the reaction mixture. The amount of the amine base and / or acid may be 0.5 to 100 equivalents, preferably 0.8 to 10 equivalents, and most preferably 1 to 3 equivalents, relative to the amount of the precursor. The formation of the pre-activated precursor may improve the formation of spiropyran of formula (1). The amine base is preferably a primary or secondary amine base, more preferably a primary amine base. The primary amine base may be an alkylamine, preferably methylamine, ethylamine, propylamine, or a mixture thereof. Methylamine may be preferred because it can be readily removed from the reaction mixture. The acid may be an inorganic or organic acid, preferably a carboxylic acid. More preferably, the carboxylic acid may be formic acid or acetic acid.

[0149] Alternatively, in another embodiment, a secondary amine base, such as piperidine, may be preferred. Furthermore, the precursor may be functionalized with a group that can be reduced or oxidized. Following reduction or oxidation, the spiropyran either undergoes an exchange reaction to produce another spiropyran, or is treated with a primary amine base to produce the corresponding salicylaldehyde and 2-methyleneindoline. In one embodiment, R' 2 To R' 5and R' 10 to R' 13 may contain groups that can be reduced or oxidized. Groups that can be reduced or oxidized include, but are not limited to, formyl, hydroxyl, ketone, carboxylic acid, cyano, nitro, and amino.

[0150] In another embodiment, the present application can be directed to a method of making a precursor represented by the following formula (2):

[0151] (Formula (2)); wherein R' 1 , R' 6 to R' 9 are independently selected from the group consisting of H, D, substituted or unsubstituted C1-C 10 alkyl, preferably methyl; substituted or unsubstituted C6-C 32 aryl, preferably phenyl; substituted or unsubstituted C2-C 20 alkynyl, and substituted or unsubstituted C2-C 20 alkenyl, and benzyl; X is C; Z is C; Y is O; R' 2 to R' 5 and R' 10 to R' 13 are independently selected from the group consisting of H, D, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C6-C 32 aryl, substituted or unsubstituted C1-C 20 alkoxy, substituted or unsubstituted C6-C 48 aryloxy, F, CI, CF3, CN; wherein two adjacent groups can be linked to each other to form a fused ring structure, preferably a fused aromatic C6ring; and a substituent of the following formula: , wherein R 19 is as defined in the description above; wherein R 2 to R 5 and R 10 to R 13 at least one of R , The method comprises the following steps: providing a reactant, wherein the reactant is a spiropyran represented by the following formula (2A):

[0152] (2a) (formula (2a)); wherein R' 2 to R' 5 and R' 10 to R' 13 at least one of R'2to R'5of the reactant of formula (2a) is a halogen atom selected from CI, Br and I; and at least one of R'10to R'13of the reactant of formula (2a) is also a halogen atom selected from CI, Br and I; and wherein at least two or more halogen atoms are reacted with the warmamide in the metal-halogen exchange reaction to obtain the precursor according to formula (2). Thus, the obtained precursor of formula (2) can contain at least two, preferably two substituents of the following formula: the halogen atoms of the reactant are reacted with an organolithium reagent or Grignard reagent, preferably with an organolithium reagent, in a metal-halogen exchange reaction to obtain a metal-spiropyran species, subsequently the metal-spiropyran species is reacted with a warmamide of the following formula: , wherein R 28 and R 29 are selected from substituted or unsubstituted Ci-C 10 alkyl; substituted or unsubstituted C6-C 32 aryl; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl, preferably R 28 and R 29 are each methyl, to obtain the precursor of formula (2), wherein the precursor of formula (2) is obtained after an acidic aqueous solution work-up, preferably.

[0153] The acidic aqueous solution work-up can be performed after the metal-spiropyran species is reacted with the warmamide to obtain the precursor of formula (2). The acidic aqueous solution work-up can be necessary to form the desired ketone moiety. The acidic aqueous solution work-up can contain at least water and an acid, such as preferably an inorganic acid or an organic acid. More preferably, the acidic aqueous solution work-up can contain at least water and an acid selected from hydrochloric acid, acetic acid or formic acid.

[0154] Preferably, at least one of R'2to R'5of the reactant of formula (2a) is a halogen atom selected from CI, Br and I, and at least one of R'10to R'13of the reactant of formula (2a) is also a halogen atom selected from CI, Br and I, and wherein at least two or more halogen atoms are reacted with the warmamide in the metal-halogen exchange reaction to obtain the precursor according to formula (2). Thus, the obtained precursor of formula (2) can contain at least two, preferably two substituents of the following formula: .

[0155] Preferably, the organolithium reagent is an alkyl organolithium reagent or an aryl organolithium reagent, more preferably, the organolithium reagent is an alkyl organolithium reagent. The alkyl organolithium reagent is preferably selected from n-butyllithium, sec-butyllithium, tert-butyllithium, preferably n-butyllithium.

[0156] Preferably, the halogen atom in the reactant of formula (2) is Br.

[0157] In a particularly preferred embodiment of the present application, the precursor of formula (2) can be obtained according to the following reaction scheme: , wherein the substituents are the same as defined above. The person skilled in the art knows that the spiropyran reactant and product in the reaction scheme can contain additional substituents, which are omitted in the reaction scheme for the sake of readability. Thus, the person skilled in the art also knows that the bromo substituent can equally be provided at any other position of the aryl group, resulting in the corresponding isomer, wherein the carbonyl substituent is also provided at the corresponding position, if necessary.

[0158] Preferably, the method of manufacturing the precursor of formula (2) is followed by a method of manufacturing the spiropyran of formula (1).

[0159] For the method of manufacturing the precursor of formula (2), the person skilled in the art knows, without being bound by any theory, that for the reaction with the metal organic reagent, the halogenated spiropyran can be preferred, as the spiropyran moiety itself can be rather inert. Methods known in the art can make use of the combination of n-butyllithium + acyl chloride / anhydride or n-butyllithium + nitrile. The combination of n-butyllithium with acyl chloride / anhydride has the disadvantage that the carbonyl group can be formed directly, so that a second lithiated spiropyran can add to the carbonyl group. Furthermore, the reaction mixture can be strongly basic, which can promote aldol condensation of the already formed product. Nitriles are less reactive than acyl chlorides with n-butyllithium, which can have the disadvantage that they require longer reaction times or higher temperatures than the usually applied -78°C. This can lead to non-specific side reactions and lower yields.

[0160] Therefore, surprisingly, the present invention solves the problems of the prior art by providing a functionalized precursor spiropyran and subsequently using it in an exchange reaction. A novel method for introducing a carbonyl group onto spiropyran is to perform a metal-halide exchange of the halide on the spiropyran using an organolithium substance such as n-butyllithium, and then react the resulting organolithium substance with a venereberamide. The reaction is surprisingly effective, with high yields, preferably quantitative yields. The only byproducts of the metal halide exchange reaction and the subsequent carbonyl introduction are likely to be a few percent of the total yield, such as less than 5 mol% of dehalogenated spiropyran. The low amount of byproducts has a surprising effect, namely, it simplifies the desired purification of spiropyran, enabling manufacturing beyond laboratory scales to industrial scales. This novel method may, for the first time, allow the introduction of more than one carbonyl moiety into spiropyran by providing a spiropyran precursor having two halogen atoms. Those skilled in the art will note that this reaction can be very efficient because the carbonyl group cannot be introduced stepwise. The reaction is tolerant to several functional groups substituted on spiropyran, including alkyl, alkoxy, CF3 and aryl groups substituted by these substituents, as defined above.

[0161] 1.1. A indolium salts of formula (3) and spiropyrans of formula (2)

[0162] In another aspect, the present invention can provide a method for manufacturing spiropyran represented by the following formula (1):

[0163] (Equation (1)); The method includes the following steps: A precursor is provided, wherein the precursor is a spiropyran represented by the following formula (2):

[0164] (Equation (2)); Provide reactants, wherein the reactants are Indolonium salts represented by the following formula (3):

[0165] (Equation (3)) Or the corresponding 2-methyleneindoline compounds; Optionally, the precursor may be pre-activated; A reaction mixture comprising the precursor or optionally a pre-activated precursor and the reactant are provided to obtain the spiropyran of formula (1); The spiropyran, the precursor, and the reactant are different from each other; If the reactant is an indoleon salt of formula (3), then the obtained spiropyran of formula (1) is represented by the following formula (1A):

[0166] (Equation (1A)), In equation (1A), R" 1 To R" 8 Independently with R" of equation (3) 1 To R" 8 The same, and R' of equation (1A) 9 To R' 13 Independently with R' of equation (2) 9 To R' 13 same; Preferably, the reactant is an indoleonium salt of formula (3), wherein X, Hal, and R" A 、R" B and R" 1 To R" 8 Substituents as defined above.

[0167] Therefore, R' of the spiropyran of formula (2) and the spiropyran of formula (1A) are precursors. 9 、R' 10 、R' 11 、R' 12 and R' 13 R corresponding to the spiropyran in equation (1) 9 R 10 R 11 R 12 and R 13 Therefore, the spiropyran of formula (2) and the spiropyran of formula (1A) as precursors may contain R' 9 、R' 10 、R' 11 、R' 12 and R' 13 The substituents of the spiropyran of formula (1) described above as a preferred embodiment are R 9 R 10 R 11 R 12 and R 13 same.

[0168] Therefore, the indoleonium salt of formula (3) and the spiropyran of formula (1A) R" 1 、R" 2 、R" 3 、R" 4 、R" 5 、R" 6 、R" 7 and R" 8 R corresponding to the spiropyran in equation (1) 1 R 2 R 3R 4 R 5 R 6 R 7 and R 8 . Thus, the indolenium salt of formula (3) and the spiropyran of formula (1A) can contain substituents R" 1 R" 2 R" 3 R" 4 R" 5 R" 6 R" 7 and R" 8 which are identical to R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 of the spiropyran of formula (1) as preferred embodiment above.

[0169] More preferably, the number of electron withdrawing substituents in R" 2 to R" 5 of formula (3) is higher than the number of electron withdrawing substituents in R' 2 to R' 5 of formula (2).

[0170] Even more preferably, the electron withdrawing substituents in R" 4 of formula (3) are stronger than the electron withdrawing substituents in R' 4 of formula (2), and / or the substituents in R" 4 of formula (3) are selected from the group consisting of carbonyl; chlorine; bromine; iodine; formyl; carbonate; carbonic acid ester; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 aryloyl; ketone; acyl; benzoyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkylsulfone; sulfonamide; SO2Me; SO2NH2.

[0171] The number of electron withdrawing substituents can have an influence on the acidity of the compound. This can have the beneficial effect that the newly formed 2-methyleneindolinium salt can be directly protonated to the corresponding indolenium salt. Thus, the newly formed 2-methyleneindolinium salt can not be available for a second condensation reaction, thereby shifting the equilibrium towards the formation of the desired spiropyran of formula (1) and hindering the reverse reaction in this equilibrium.

[0172] Furthermore, if R' 2 to R' 5If the substituents in the 2-methyleneindole that is newly formed make the 2- methyleneindole more basic, then the acid-base equilibrium can force the reaction towards the formation of the substituted indolium salt of R' 2 to R' 5 corresponding indolium salt of the substituted indole is moved.

[0173] Surprisingly, it has been found that the equilibrium of the reaction can be independent of the nature of the salicylaldehyde, which makes the reaction very versatile and the spiropyrans of formula (1) can be obtained for the first time by the present application. Furthermore, it has been found that the method using the indolium salt of formula (3) is surprisingly mild when the salicylaldehyde is substituted with electron withdrawing groups, so that the method can be applicable in the presence of most substituents that can be sensitive to acids or bases.

[0174] Preferably, the indolium salt of formula (2) is formed from the corresponding 2- methyleneindoline compound and an acid, wherein preferably the acid is an organic acid or an inorganic acid, more preferably the acid is selected from hydrochloric acid, acetic acid or formic acid.

[0175] The reactant, i.e. the indolium salt of formula (3), can be pre-activated by converting the indolium salt of formula (3) into the corresponding 2-methyleneindoline compound before mixing the precursor with the reactant in the reaction mixture, which is then added to the reaction mixture. The corresponding 2-methyleneindoline compound can be represented by the following formula (3A):

[0176] (formula (3A)), wherein the substituents are as defined in the indolium salt of formula (3). Thus, the corresponding 2-methyleneindoline compound can be used instead of adding the indolium salt of formula (3).

[0177] The reactant, i.e. the indolium salt of formula (3), can be pre-activated by converting the indolium salt of formula (3) into the corresponding 2-methyleneindoline compound before mixing the precursor with the reactant in the reaction mixture, which is then added to the reaction mixture. The corresponding 2-methyleneindoline compound can be represented by the following formula (3A):

[0178] .

[0179] Based on the amount of precursor of formula (2), an excess, i.e. more than 1.1 equivalents, more preferably 1.1 to 1.5 equivalents, more preferably 1.1 to 1.2 equivalents, most preferably 1.2 equivalents, of the indolium salt of formula (3) can be provided to the reaction mixture. If the indolium salt of formula (3) or the corresponding 2-methyleneindolinium is used in excess, it can add to the spiropyran a second time and undergo another addition or condensation. Thus, the reaction can be carried out with a slight excess of the indolium salt of formula (3).

[0180] Preferably, the concentration of the acid or base can be adjusted to provide a total amount of 0.1 equivalents of the deprotonated 2-methyleneindolinium derivative throughout the reaction mixture.

[0181] It can be particularly preferred that the following indolium salts are used: .

[0182] In another aspect of the application, an excess, i.e. at least 2 equivalents, preferably 2.5 to 100 equivalents, more preferably 3 to 10 equivalents, most preferably 3.5 to 5 equivalents, of the indolium salt of formula (3) or the corresponding 2-methyleneindolinium compound can be provided to the reaction mixture containing the spiropyran of formula (2). When using the indolium salt, an amine base in the range of 1 to 3 equivalents can be provided to the reaction mixture. When applying the 2-methyleneindolinium, an acid in the range of 1 to 2 equivalents can be provided. Given these conditions, the adduct of the product spiropyran having the following formula can be obtained from the indolium salt or the 2-methyleneindolinium compound as reactant: , wherein R x may independently of each other represent the corresponding substituents R 2 to R 5 which can be the same or different. R R may independently of each other represent the substituents R 10 to R 13 which can be the same or different.

[0183] The adduct can be readily separated (purified) from the reaction mixture, preferably by precipitation. In another reaction, the adduct can be treated with acid in a polar solvent to provide the product spiropyran. In the second reaction, 1% to 50%, preferably 5% to 20%, more preferably 10% acid is used. The acid can be an inorganic or organic acid, preferably selected from hydrochloric acid, sulfuric acid, carboxylic acid, methanesulfonic acid, toluenesulfonic acid, or trifluoroacetic acid, more preferably formic acid or acetic acid. The polar solvent can be selected from THF, nitromethane, MTBE, methanol, ethanol, 2-propanol, 1-butanol, ethylene glycol, preferably ethanol or methanol. The temperature of the second reaction can be from 0°C to 150°C, preferably from 15°C to 100°C, more preferably from 20°C to 70°C, and most preferably 25°C. Therefore, the formation of the adduct can have the advantage that it can be surprisingly easily separated from the reaction mixture and can be further reacted to obtain the desired spiropyran of formula (1).

[0184] The reaction mixture may additionally contain a catalytic amount of a base, preferably a secondary amine base. The secondary amine base may preferably be piperidine. The catalytic amount of the base relative to the amount of the precursor is preferably in the range of 0.02 to 0.2 equivalents, more preferably in the range of 0.05 to 0.15 equivalents, and most preferably 0.1 equivalents.

[0185] In one embodiment, 1 to 1.3 equivalents of piperidine can be used to preactivate the indoline salt before it is added to the reaction mixture to form the corresponding 2-methyleneindoline, which is then added to the reaction mixture along with the precursor of formula (2).

[0186] In one embodiment, the reaction mixture containing the indolon salt of the corresponding 2-methyleneindoline may be base-free.

[0187] Preferably, the precursor R' of formula (2) 2 To R' 5 At least one, more preferably each, may be hydrogen or deuterium, and at least one of R"2 to R"5 of the indoleon salt of formula (3) and the corresponding 2-methyleneindoline may be an electron-withdrawing group, preferably benzoyl or methyl sulfone (SO2Me). Alternatively, if the indoleon salt of formula (3) and the corresponding 2-methyleneindoline R" 2 To R" 5 If it is not an electron-withdrawing group, then the precursor R' of formula (2) 2 To R' 5 The electron-donating substituent is as defined above, preferably methoxy. To form the desired spiropyran of formula (1A), if R' of formula (2) 10 To R' 13At least one of them may be independently selected from substituted or unsubstituted C1-C6 alkyl groups, carboxylic acids and their salts, sulfonic acids and their salts, phosphonic acids and their salts, fluorine, bromine, chlorine, iodine, substituted or unsubstituted C2-C6 alkyl groups. 49 Alkyl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C2-C 49 Aryl acyl groups, CN, NO2, aldehydes, ketones, sulfones, alkyl sulfones; sulfonamides, SO2Me, SO2Ph, SO2NH2, CF3, OCF3, may accelerate the reaction. Preferably, R' in formula (2) 11 For CF3. R' through equation (2) 10 To R' 13 Having electron-withdrawing groups, it has been surprisingly found that they can promote reactions with indolonium salts of formula (3) and the corresponding 2-methyleneindoline, so as to allow for a wider variety of substituents at the indolonium salts of formula (3) and the corresponding 2-methyleneindoline to form spiropyrans of formula (1A).

[0188] A polar solvent, preferably an alcohol, and most preferably n-butanol or ethanol, can be added to the reaction mixture. The polar solvent can be THF, water, acetic acid, nitromethane, formic acid, methanol, ethanol, or isopropanol. The alcohol can be methanol, ethanol, isopropanol, n-butanol, or ethylene glycol. The reaction mixture can be stirred at a temperature above 40°C, preferably in the range of 40°C to 150°C, and more preferably in the range of 70°C to 120°C. The reaction mixture can be stirred for more than 1 hour, preferably in the range of 0.5 hours to 48 hours, more preferably in the range of 1 hour to 12 hours, and most preferably in the range of 1 hour to 2 hours. If an indoleonium salt of formula (3) is used as a reactant, the method of the present invention can produce spiropyran of formula (2) in a yield of more than 80%, such as 80% to 100%, preferably 90% to 99%.

[0189] In a preferred embodiment, the precursor R' of formula (2) 2 To R' 5 It can be hydrogen, R" of the indoleonium salt of formula (3) 2 To R" 5 At least one of them can be a substituted or unsubstituted benzoyl group. The amount of the indoleonium salt of formula (3) relative to the precursor can be 0.9 to 1.2 equivalents, preferably 1.0 to 1.1 equivalents. Piperidine can be used as a catalyst, and ethanol can be used as a solvent. After stirring the reaction mixture at 70°C for 1 to 2 hours, the desired product, namely the spiropyran of formula (1), can be obtained in a yield of more than 80%, in addition to the newly formed indoleonium salt as a further product. If the R" of the indoleonium salt of formula (3) 2 To R" 5substituted by a strong electron withdrawing group, then preferably R' of the precursor of formula (2) 2 to R' 5 may be chosen to be alkoxy, preferably methoxy, so that similar high yields of more than 80% can be obtained.

[0190] A scavenger, such as a template, can be added to the reaction mixture. The scavenger can have a favorable interaction with the product, i.e. the spiropyran of formula (1) or the corresponding merocyanine or the newly formed 2-methyleneindolinium or the corresponding indolium salt which can be obtained as a further product. Thus, the equilibrium of the reaction can be shifted to the product side so that more of the desired spiropyran of formula (1) can be obtained. A non-limiting example of a scavenger is a proton which can trap the formed 2-methyleneindolinium as the corresponding indolium salt. If the scavenger is an acid, a proton can be obtained.

[0191] 1.1. B salicylaldehydes of formula (4) and spiropyrans of formula (2)

[0192] In a preferred aspect, the present application can provide a method of manufacturing a spiropyran represented by the following formula (1):

[0193] (formula (1)), wherein the method comprises the steps of providing a precursor, wherein the precursor is a spiropyran represented by the following formula (2):

[0194] (formula (2)); and providing a salicylaldehyde represented by the following formula (4):

[0195] (formula (4)); optionally pre-activating the precursor, then providing a reaction mixture comprising the precursor or the optionally pre-activated precursor and the reactant to obtain the spiropyran of formula (1); wherein the spiropyran, the precursor and the reactant are different from each other; wherein if the reactant is a salicylaldehyde of formula (4), the obtained spiropyran of formula (1) is represented by the following formula (1B):

[0196] (formula (1B)), wherein R' of formula (1B) 1 to R' 8 are independently R' of formula (2) 1 to R' 8are the same as R 9 are the same as R 13 independently of R 9 independently of R 13 are the same as R Thus, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 of the spiropyran of formula (1B) as precursors correspond to R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 of the spiropyran of formula (1). Thus, the substituents R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 of the spiropyran of formula (2) and of the spiropyran of formula (1B) as precursors can be the same as R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 of the spiropyran of formula (1) as preferred embodiments.

[0197] Thus, additionally, R" 9 , R" 10 , R" 11 , R" 12 and R" 13 of the salicylaldehyde of formula (4) and of the spiropyran of formula (1B) correspond to R 9 , R 10 , R 11 , R 12 and R 13 of the spiropyran of formula (1). Thus, the substituents R" 9 , R" 10 , R" 11 , R" 12 and R"13 The substituents of the spiropyran of formula (1) described above as a preferred embodiment are related to the R group. 9 R 10 R 11 R 12 and R 13 same.

[0198] Preferably, the reactant is salicylaldehyde of formula (4), wherein A, B, Z, Y and R... 9 To R" 13 This is a substituent as defined above. More preferably, R" 9 For H or D; and R" 10 To R" 13 Independently selected from H; D; halogen; toluenesulfonyl; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; oxime; aldehyde, NO2; CN, (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; sulfonic acid or its salt; carboxylic acid or its salt; boric acid or its salt; phosphonic acid or its salt; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; NH2; OH; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy group; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; SiR'3, -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C. 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl groups, with two R's, can form a ring structure.

[0199] It was therefore surprising that it has been found that a spiropyran of formula (2) can be treated with a low acidic salicylaldehyde of formula (4) to exchange, thereby liberating a new salicylaldehyde from the spiropyran.

[0200] The salicylaldehyde of formula (4) can be used in excess, preferably more than 1.1 equivalents, more preferably in the range of 1.1 to 2.0 equivalents, relative to the amount of the precursor. Thus, the formation of the spiropyran of formula (1), which can have a low solubility, can be enhanced by shifting the equilibrium to the product side. Thus, a larger amount of the new salicylaldehyde can be liberated as a by-product.

[0201] .

[0202] The reaction can preferably be carried out in a polar solvent as defined above, more preferably in an alcohol as defined above, more preferably in ethanol. The substituent R Y is preferably selected from non-polar groups. R Y i.e. R in the salicylaldehyde of formula (4) 10 to R 13 may be more preferably selected from H, tert-butyl, bromo or chloro.

[0203] Preferably, the precursor of formula (2) has been pre-activated with a nucleophile. Preferably, the nucleophile is an amine base, as defined above with respect to the precursor.

[0204] A scavenger, such as a template, can be added to the reaction mixture. The scavenger can have a favorable interaction with the product, i.e. the spiropyran of formula (1) or the corresponding merocyanine or the newly formed salicylaldehyde as a by-product. Thus, the equilibrium of the reaction can be shifted to the product side, so that more of the desired spiropyran of formula (1) containing the substituents R Q and R Y can be obtained.

[0205] 1.1.C Spiropyrans of formula (2) and spiropyrans of formula (5) in exchange reactions

[0206] In another aspect, the present application can provide a method of manufacturing a spiropyran represented by the following formula (1):

[0207] (formula (1))

[0208] wherein the method comprises the steps of providing a precursor, wherein the precursor is a spiropyran represented by the following formula (2):

[0209] (formula (2)); and a spiropyran represented by the following formula (5):

[0210] (Form (5)), The reaction mixture comprising the precursor or optionally pre-activated precursor and the reactant is provided to obtain the spiropyran of formula (1), wherein the spiropyran, the precursor and the reactant are different from each other; wherein if the reactant is a spiropyran of formula (5), then the obtained spiropyran of formula (1) is represented by formula (1A), wherein R" 1 to R" 8 are independently the same as R" 1 to R" 8 of formula (5), and R' 9 to R' 13 are independently the same as R' 9 to R' 13 of formula (2), or then the obtained spiropyran of formula (1) is represented by formula (1B), wherein R' 1 to R' 8 are independently the same as R' 1 to R' 8 of formula (2), and R" 9 to R" 13 are independently the same as R" 9 to R" 13 of formula (5).

[0211] The preferred embodiments of the substituents of the spiropyran of formula (1) also apply to the substituents of the spiropyran of formula (1A) and the spiropyran of formula (1B) as defined above.

[0212] Preferably, the reactant is a spiropyran of formula (5), wherein the reaction mixture can comprise an additional catalyst. More preferably, the catalyst can be an amine base. Even more preferably, the catalyst can be a primary amine base or a secondary amine base. More preferably, the catalyst can be a Ci-C6alkyl amine, most preferably piperidine, ethylamine or methylamine. In an alternative preferred embodiment, the catalyst can be 2-methyleneindoline. The catalyst can be added in catalytic amounts, such as 0.02 to 0.2 equivalents, preferably 0.05 to 0.15 equivalents, relative to the amount of the precursor of formula (2). The catalyst can pre-activate the precursor.

[0213] The reaction mixture of the method can comprise a solvent, preferably a polar solvent as defined above, more preferably an alcohol as defined above, even more preferably ethanol or n-butanol. The reaction can be carried out at a temperature of 0 °C to 200 °C, 10 °C to 180 °C, 20 °C to 170 °C, 30 °C to 160 °C, 40 °C to 140 °C, or 60 °C to 100 °C. The reaction can be carried out at a pressure of 0.01 to 100 atmospheres, 0.1 to 10 atmospheres, or 0.5 to 1.5 atmospheres, such as normal pressure (= 1 atmosphere, corresponding to 101325 pascal). In another embodiment, the reaction can be carried out in an alcohol at elevated temperature, preferably in the range of 40 °C to 140 °C, more preferably in the range of 60 °C to 100 °C. In another preferred embodiment, the molar ratio of the precursor (i.e. the precursor of formula (2)) to the reactant (i.e. the reactant of formula (3) or formula (4) or formula (5)) can be 1 : 100 to 100: 1, 1 : 50 to 50: 1, 1 : 20 to 20: 1, or 1 : 10 to 10: 1. In another preferred embodiment, the concentration of the precursor (i.e. the precursor of formula (2)) in the reaction mixture can be 0.00001 M to 100 M, 0.001 M to 1 M, or 0.001 M to 0.1 M. In another preferred embodiment, the concentration of the reactant (i.e. the reactant of formula (3) or formula (4) or formula (5)) in the reaction mixture can be 0.00001 M to 100 M, 0.001 to 1 M, or 0.001 to 0.1 M. In a particularly preferred embodiment, the solvent is ethanol and the elevated temperature can be 70 °C, or the solvent is n-butanol and the elevated temperature can be 120 °C. In another preferred embodiment, after providing the reaction mixture comprising the precursor or optionally the pre-activated precursor and the reactant, the spiropyran of formula (1) can be obtained after 24 hours, preferably in the range of 24 hours to 10 days, more preferably in the range of 6 to 8 days, most preferably at 7 days. Without being bound by any theory, it is believed that under the above conditions the following equilibrium can be obtained. Thus, the equilibrium is expected to be on the product side, i.e. the right side of the equation.

[0214] .

[0215] To obtain the desired spiropyran, the desired spiropyran has a lower solubility in the solvent than the precursor. Thus, the equilibrium can be on the product side. If the reaction mixture can contain a polar solvent, such as an alcohol, then R Q and R Y , i.e. R" 2 to R" 5 and R' 10 to R' 13 , or R 2 to R 5 and R 10to R 13 , each can be one or more non-polar substituents, preferably aromatic systems, such as substituted or unsubstituted C6-C 48 aryl, alkyl, preferably substituted or unsubstituted C1-C 20 alkyl; substituted or unsubstituted C3-C 20 cycloalkyl; or halides, preferably bromides. Having one or more non-polar substituents in formula (I) can have the effect in polar solvents that the spiropyrans of formula (I) can precipitate out of the reaction mixture, so that the equilibrium is shifted to the product side, thus enabling control of the reaction. In addition, one of the formed spiropyrans can be thermodynamically more favorable than the corresponding merocyanine. This can mainly lead to the formation of stable spiropyrans and can also shift the equilibrium to the product side. For example, if the unsubstituted spiropyrans contain R Q , R Y = H, the formation of higher substituted spiropyrans with R R and R X as substituents other than H can be improved. Thus, the equilibrium is also shifted to the product side.

[0216] On the other hand, the reaction mixture can additionally comprise a scavenger, i.e. a template, and the scavenger is able to bind the obtained spiropyrans or bind the obtained side products in the reaction mixture, so that the equilibrium can be shifted to the product side. In other words, such a scavenger can be a template added to the reaction mixture, which interacts favorably with at least one product spiropyrans or the corresponding merocyanine, thus providing a shift of the equilibrium to the product side.

[0217] 2. Spiropyrans of formula (1)

[0218] Another aspect of the present application is a spiropyrans represented by the following formula 1:

[0219] (Formula (1)); wherein X is selected from S, C or N, X is selected from S, C or N; if X is S, then R 6 , R 7 , R' 6 , R' 7 , R" 6 , R" 7 may be absent; if X is N, then R 7 , R' 7 , R" 7 may be absent, wherein Y is selected from O, S or N; when Y is N, the substituents contain R 13atoms necessary to form a ring structure selected from the group consisting of benzimidazole, indoline, indole, dihydroquinoline and tetrahydroquinoline, preferably Y is O; wherein Z is selected from N or C, preferably Z is C; wherein R 1 to R 13 are independently selected from the group consisting of H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C 20 alkyl; substituted or unsubstituted C3-C 20 cycloalkyl; substituted or unsubstituted C6-C 48 aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 arylacyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; NH2; substituted or unsubstituted C1-C 20 alkyl ester; substituted or unsubstituted C6-C 48 aryl ester; substituted or unsubstituted C1-C 20 alkylamide; substituted or unsubstituted C6-C 48 aryl amide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, both R' can form a ring structure; substituted or unsubstituted carboxylic acid and its salts; substituted or unsubstituted sulfonic acid and its salts; substituted or unsubstituted sulfonate ester; substituted or unsubstituted sulfonamide; formyl; ether; thioether; carbonate; carbonic ester; sulfate; boronic acid; boronic ester; phosphonic acid; phosphonic ester; phosphine; phosphate; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinic ester; sulfinate; thiole ester, sulfoxide; sulfone; hydrazide; thioaldehyde; ketone; thione; oxime; hydrazine; nitroso; azo; diazo; diazonium; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; hydroperoxide; peroxide; acetal; ketal; orthoester; orthocarbonate; ammonium; imine; imide; azide; nitrate; isonitrile; nitrite; substituted or unsubstituted thiocarbamates; substituted or unsubstituted carbamates; substituted or unsubstituted ethers; substituted or unsubstituted polyether carbamates; substituted or unsubstituted aryl azo; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; wherein two adjacent groups can be linked to each other to form a fused ring structure, preferably a fused aromatic C6 ring; wherein if R1 to R 13 one or more substituents, then said substituents are independently selected from the group consisting of D; halogen; NO2; CN, C2-C 49 alkylacyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; substituted or unsubstituted C2-C 49 arylacyl; (meth)acrylate; tosyl; sulfonic acid or a salt thereof; carboxylic acid or a salt thereof; boronic acid or a salt thereof; phosphonic acid or a salt thereof; NR'3 + wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; NH2; and OH; wherein if present, R 10 to R 13 and R 2 to R 5 two adjacent groups of R and wherein R 2 to R 5 and R 10 to R 13 at least one substituent of R 49 is selected from the group consisting of chloro; bromo; iodo; formyl; carbonate; carboxylate; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 14 arylacyl; ketone; acyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and tosyl; or one of the following: , , , , , , and , wherein R 14 to R 27 are independently selected from the group consisting of H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C 20 alkyl; substituted or unsubstituted C3-C 20 cycloalkyl; substituted or unsubstituted C6-C 48 aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49alkyl acyl; substituted or unsubstituted C2-C 49 aryl acyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy and NH2; substituted or unsubstituted C1-C 20 alkyl ester; substituted or unsubstituted C6-C 48 aryl ester; substituted or unsubstituted C1-C 20 alkyl amide; substituted or unsubstituted C6-C 48 aryl amide; NR'2; SiR'3; -0-SiR'3, where R' is independently selected from the group consisting of substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; substituted or unsubstituted carboxylic acid and its salts; substituted or unsubstituted sulfonic acid and its salts; substituted or unsubstituted sulfonate ester; substituted or unsubstituted sulfonamide; formyl; ether; thioether; carbonate; carbonic ester; sulfate; boronic acid; boronic ester; phosphonic acid; phosphonic ester; phosphine; phosphate; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinic ester; sulfinate; thiole ester, sulfoxide; sulfone; alkyl sulfone; hydrazide; thioaldehyde; ketone; thione; oxime; hydrazine; nitroso; azo; diazo; diazonium; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; hydroperoxide; peroxide; acetal; ketal; orthoester; orthocarbonate; ammonium; imine; imide; azide; nitrate; isonitrile; nitrite; substituted or unsubstituted carbamate; substituted or unsubstituted ether; substituted or unsubstituted polyether carbamate; substituted or unsubstituted aryl azo; substituted or unsubstituted C2-C 20 alkynyl and substituted or unsubstituted C2-C 20 alkenyl; wherein if R 14 to R 27 one or more substituents present in one or more of R 49 alkyl acyl; substituted or unsubstituted C1-C 20 alkoxy; substituted or unsubstituted C6-C 48 aryloxy; substituted or unsubstituted C2-C 49 aryl acyl; (meth)acrylate; tosyl; sulfonic acid or its salt, carboxylic acid or its salt, boronic acid or its salt, phosphonic acid or its salt, NR'3 + wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; NH2; and OH; and R15 and R 16 may be connected to each other to form an unsubstituted or substituted ring structure, and wherein R 2 to R 5 and R 10 to R 13 at least one further substituent is selected from the group consisting of chloro; bromo; iodo; formyl; carbonate; carboxylate; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C 49 arylacyl; ketone; acyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkylsulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and tosyl; and / or wherein R 2 to R 5 and R 10 to R 13 at least one further substituent is selected from the group consisting of sulfonic acid or a salt thereof; carboxylic acid or a salt thereof; boric acid or a salt thereof; phosphonic acid or a salt thereof; NR'3 + wherein R' is independently selected from the group consisting of H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; substituted or unsubstituted sulfonate; substituted or unsubstituted sulfonamide; phosphonate; phosphine; phosphate; sulfinic acid; sulfite; sulfinate; sulfoxide; sulfone; alkylsulfone; oxime; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; ammonium; substituted or unsubstituted carbamate; (meth)acrylate; tosyl; NH2; and OH.

[0220] Preferably, at least one of R 2 to R 5 is selected from one of the following formulae: , , , , , , and , wherein R 14 to R 27 are as defined above. Furthermore, at least one of R 10 to R 13 may be selected from the group consisting of chloro; bromo; iodo; formyl; carbonate; carboxylate; ester; amide; CF3; substituted or unsubstituted C2-C 49 alkylacyl; substituted or unsubstituted C2-C49 Aryl acyl; ketone; acyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl.

[0221] On the other hand, R can be added alternatively or in addition. 10 To R 13 At least one other substituent is selected from sulfonic acids or their salts; carboxylic acids or their salts; boric acids or their salts; phosphonic acids or their salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; (meth)acrylates; toluenesulfonyl group; NH2 and OH.

[0222] In addition, R is preferred 10 To R 13 At least one of them, more preferably R 10 and R 12 To R 13 At least one of the following is selected from one of the following formulas: , , , , , , and , Where R 14 To R 27 As defined above. Furthermore, R 2 To R 5 At least one of them may be selected from chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl.

[0223] On the other hand, R can be added alternatively or in addition. 2 To R 5 At least one other substituent is selected from sulfonic acids or their salts; carboxylic acids or their salts; boric acids or their salts; phosphonic acids or their salts; NR'3+ wherein R' is independently selected from H, D, substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C6-C 48 aryl, two R' can form a ring structure; substituted or unsubstituted sulfonate; substituted or unsubstituted sulfonamide; phosphonate; phosphine; phosphate; sulfinic acid; sulfite; sulfinate; sulfone; sulfoxide; alkylsulfoxide; oxime; isocyanide; cyanate; isocyanate; thiocyanate; isothiocyanate; ammonium; substituted or unsubstituted carbamate; (meth)acrylate; tosyl; NH2, and OH.

[0224] Preferably, R 2 to R 5 and at least one of R 10 to R 13 is a substituent selected from one of the following formulae: , , , , , , and , wherein R 14 to R 27 are as defined above.

[0225] Preferably, the selected substituent on one of R 2 to R 5 is different from the selected substituent on one of R 10 to R 13 .

[0226] In one embodiment, at least two substituents of R 2 , R 3 , R 5 and R 10 to R 13 are independently selected from or an electron withdrawing group.

[0227] In another embodiment, at least two substituents of R 2 to R 5 , R 10 , R 12 , R 13 are independently selected from or an electron withdrawing group.

[0228] In another embodiment, one of R 2 to R 5 is and R 10 to R13 One of them is , where R 19 They are the same.

[0229] In one implementation, R 2 To R 5 One of them is And R 10 To R 13 One of them is , where R 19 They are different.

[0230] In one implementation, R 2 To R 5 At least one of them is an electron-withdrawing group, and / or R 4 R 10 R 12 R 13 At least one of them is At least R 12 R 13 At least one of them is , more preferably R 13 for .

[0231] In one implementation, R 2 To R 5 and / or R 10 To R 13 At least one of them is a substituted aryl acyl group and contains an electron-withdrawing group as a substituent, preferably the substituent is selected from CN, CF3, F, Cl, Br, I, OCF3, substituted or unsubstituted alkyl esters, substituted or unsubstituted aryl esters, SO2Me and SO2NH2.

[0232] In one implementation, R 2 To R 5 At least one of them is a substituted or unsubstituted aryl acyl group, and R 10 To R 13 At least one of them is a substituted or unsubstituted alkyl acyl group.

[0233] In one implementation, R 4 It is an electron-withdrawing group, and R 13 for .

[0234] In one implementation, R 11 It is H or an electron-withdrawing group.

[0235] In one implementation, R 13 for .

[0236] In one embodiment, R 10 is at least one of substituted aryl acyl and contains an electron- withdrawing group as a substituent, preferably the substituent is selected from the group consisting of CN, CF3, F, Cl, Br, I, OCF3, substituted or unsubstituted alkyl ester, substituted or unsubstituted aryl ester, SO2Me and SO2NH2. 13 is at least one of substituted aryl acyl and contains an electron- withdrawing group as a substituent, preferably the substituent is selected from the group consisting of CN, CF3, F, Cl, Br, I, OCF3, substituted or unsubstituted alkyl ester, substituted or unsubstituted aryl ester, SO2Me and SO2NH2.

[0237] In one preferred embodiment, the substituted or unsubstituted aryl acyl as described above is preferably selected from the group consisting of phenyl acyl having the following formula: , 1-naphthyl acyl having the following formula: , and 2-naphthyl having the following formula: wherein R R is independently selected from the group consisting of hydrogen, deuterium, methyl, tert-butyl, substituted and unsubstituted phenyl, methoxy, CN, CF3, F, Cl, Br, I, OCF3, C1-C 20 alkyl ester, C6-C 48 aryl ester, alkyl acyl, aryl acyl, acetyl, benzoyl, NMe2, SO2Me, SO2NH2.

[0238] In one preferred embodiment, the C2-C 49 alkyl acyl is preferably a C2-C8alkyl acyl, more preferably a methyl acyl or an ethyl acyl.

[0239] In one preferred embodiment, the group of electron- withdrawing substituents or electron- withdrawing groups comprises substituents which are more electron- withdrawing than hydrogen (H). The skilled person can refer to: “A survey of Hammett substituent constants and resonance and field parameters”, Chemical Reviews, 1991, 91, 2, 165-195, wherein electron- withdrawing groups and electron- withdrawing substituents are listed.

[0240] Preferably, the (substituted or unsubstituted) C1-C 20 alkyl ester is a methyl ester or an ethyl ester.

[0241] Preferably, the (substituted or unsubstituted) C6-C 48 aryl ester is a phenyl ester.

[0242] Further preferred embodiments of the spiropyran of formula (1) can be stated in the above method of manufacturing a spiropyran of formula (1). Further preferred embodiments of the spiropyran of formula (1) can be stated in the above method of manufacturing a spiropyran of formula (1).

[0243] Particularly preferred are the following compounds: .

[0244] 3. Two-colour photoinitiators

[0245] In another aspect of the application, the spiropyrans of formula (1) can be photoinitiators, preferably dual color photoinitiators.

[0246] The photoinitiator molecule and its necessary functions can be generated in different ways. The following provides one example: .

[0247] The photoinitiator can exist in three different states, characterized as follows: Initial state (A): In the absence of light, the photoinitiator molecule exists in this state. The spiropyrans of formula (1) can be in the initial state (A).

[0248] Intermediate state (B): The B state is the electronic ground state. The corresponding merocyanine form of the spiropyrans of formula (1) can be the intermediate state B.

[0249] The intermediate state is generated from the initial state A by absorption of light with wavelength λ1.

[0250] The photoinitiator molecule has a new or stronger absorption band for light with wavelength λ2.

[0251] Alternatively, the absorption band at λ1 disappears. In the absence of light or by absorption of light with wavelength λ3, the photoinitiator molecule spontaneously returns to the initial state A.

[0252] Reaction state (C): The reaction state is generated from the intermediate state B by absorption of light with wavelength λ2.

[0253] The reaction state initiates a polymerization reaction in the vicinity of the molecule.

[0254] There is no reverse reaction to B.

[0255] In another aspect, the present invention discloses a method for locally polymerizing a starting material by using a spiropyran as a photoinitiator and irradiating the spiropyran with at least one wavelength of light, preferably with two different wavelengths of light.

[0256] In one particular embodiment, the at least one wavelength of light can have a first wavelength provided by the simultaneous absorption of two second wavelengths of photons.

[0257] The second wavelength of light can be provided by a pulsed laser source, which can have a sufficiently high intensity in order to induce a two-photon absorption event in the initial state of the two-color photoinitiator. Without being bound by any theory, the photoinitiator can switch to an intermediate state, in which it absorbs a single photon of at least one second wavelength and forms a reactive state. The reactive state can initiate a polymerization reaction, which can be used to fabricate shaped bodies, in particular shaped bodies with high resolution. The second wavelength of the pulsed laser source can be in the range of 500 to 1000 nm, preferably 600 to 800 nm. Preferably, the first wavelength and the second wavelength can be the same.

[0258] The first wavelength of light can be absorbed by the photoinitiator, thereby forming an intermediate state. The intermediate state can have a higher extinction coefficient at the first wavelength. Due to the formation of the intermediate state, the absorbance at the first wavelength can increase, thereby limiting the penetration of the first wavelength of light into the resin. The intermediate state absorbs the first wavelength of light and forms a reactive state. The reactive state initiates polymerization. Such an embodiment can be preferably used for 3D printing with stereolithography, digital light processing, or similar technologies. Due to the increased absorbance at the first wavelength, the penetration of light into the resin can be limited. The limited penetration can be advantageous for particular embodiments aiming at reducing the amount of light absorbing agents in the resin or improving the z-resolution of the printed article.

[0259] In one preferred embodiment, the method is for locally polymerizing a starting material by using a spiropyran as a photoinitiator and irradiating the spiropyran with two different wavelengths of light.

[0260] In one embodiment, the present invention discloses a method for locally polymerizing a starting material by using a spiropyran as a photoinitiator and irradiating the spiropyran with at least one light source having at least one wavelength, preferably with two light sources of different wavelengths, in accordance with the above disclosure.

[0261] In another aspect, the present invention discloses a method for locally polymerizing a starting material by two-color photopolymerization, the method comprising: A polymerizable starting material is provided which contains a photoinitiator molecule, wherein the photoinitiator molecule is a spiropyran according to the present invention, which is capable of being converted into a reactive state by a sequential photoexcitation, in which reactive state the photoinitiator molecule locally triggers polymerization of the starting material; and The starting material within the local volume is photopolymerized by irradiating a first wavelength of light and a second wavelength of light different from the first wavelength into the local volume, thereby within the local volume, The photoinitiator molecule is converted from an initial state in which the photoinitiator molecule absorbs substantially no light of the second wavelength into an intermediate state having altered optical properties compared to the initial state due to absorption of light of the first wavelength, such that the photoinitiator molecule in the intermediate state absorbs light of the second wavelength; and The photoinitiator molecule is converted from the intermediate state into the reactive state due to absorption of light of the second wavelength, thereby locally triggering the polymerization, and / or The photoinitiator molecule is capable of spontaneously converting from the intermediate state into the initial state in a thermal reaction.

[0262] The two-color photoinitiator is switched from a thermodynamically stable state A to a metastable state B in response to electromagnetic radiation of a first wavelength. B is capable of absorbing electromagnetic radiation of a second wavelength, thereby forming C, which is capable of initiating a polymerization reaction with or without a co-initiator. B can undergo a fast thermal back-reaction to return to form A, which can then be deactivated to electromagnetic radiation of the second wavelength. The application of such a two-color photoinitiator enables a photopolymerizable resin to be cured in any volume where the two wavelengths of electromagnetic radiation intersect, for example, at the projection of an image on a light sheet.

[0263] The disclosed two-color photoinitiator is characterized in that polymerization can be initiated where two different wavelengths of electromagnetic radiation interact with the same volume of polymerizable material, either simultaneously or sequentially. In a volume that interacts with only one wavelength of electromagnetic radiation, polymerization will not be initiated.

[0264] The photoinitiator molecule can be converted into a reactive state due to absorption of light of the second wavelength, thereby triggering free-radical polymerization in the local volume.

[0265] The light beam of the first wavelength and the light beam of the second wavelength can be irradiated at least partially overlapping in the local volume.

[0266] The starting material can be polymerized in several local volumes by photopolymerization, so that a three-dimensionally shaped body can be produced in the starting material.

[0267] Without being bound by any theory, the dual color photoinitiator in the thermodynamically stable form A can absorb a photon from electromagnetic radiation of the first wavelength, thereby inducing an isomerization reaction to the metastable form B. The dual color photoinitiator in the metastable form B can absorb a photon from electromagnetic radiation of the second wavelength, thereby leading to the excited state C, and can further lead to the formation of free radicals by hydrogen abstraction from a co-initiator followed by electron transfer or decomposition into free radicals; electron transfer followed by hydrogen abstraction or decomposition into free radicals; or homolytic bond cleavage can occur before or after other rearrangement reactions, forming free radicals. The dual color photoinitiator in the metastable state B that does not absorb a photon from electromagnetic radiation of the second wavelength can spontaneously return to the thermodynamically stable state A by a thermal process.

[0268] The dual color photoinitiators carry carbonyl functions, which are triplet sensitizers for the spiropyrans, and switch efficiently to the merocyanine form via the triplet, thus not showing curing with UV light alone. Electromagnetic radiation of the first wavelength leads to excitation of the initiator in form A and switching to the initiator in form B. The efficient ring opening reaction of the photo-switching motif can prevent the dual color photoinitiator from forming free radicals by first wavelength irradiation alone. The merocyanine form B can act as an internal triplet sensitizer upon irradiation with the second wavelength, which can lead to hydrogen abstraction from a co-initiator, an electron transfer reaction, or homolytic bond cleavage. Alternatively, the merocyanine form B can undergo an electron transfer reaction from the singlet excited state with a co-initiator. The choice of substituents can be such that the absorption of the merocyanine form B at the first wavelength is minimized or eliminated, and the form B is thermodynamically unstable to ensure fast thermal back reaction from B to A. The choice of substituents can also adjust the photoredox potential against the corresponding co-initiator, if present. In addition, the dual color photoinitiator can benefit from the very low or negligible quantum yield of the competing photo reaction from B to A and the high extinction coefficient of the form B, which is not absorbed by form A. The merocyanine form B can typically have a broad absorption in the visible region, thereby allowing high intensity over a wide wavelength range.

[0269] Spiropyrans of formula (1) used as dual color photoinitiators can be functionalized with several strong electron withdrawing groups for R 2 to R 5 and R 10 to R 13 In one preferred embodiment, at least one electron withdrawing group is substituted to R 10 to R 13 and at least another electron withdrawing group, which can be the same or different, can be substituted to R 2 to R 5Electron withdrawing groups can be the same or different and include, but are not limited to, cyano, formyl, keto, nitro, ester, trifluoromethyl, dicyanovinylene, methylsulfone, sulfonamide, fluorine, chlorine, bromine, and iodine. In the spiropyran form, the electron withdrawing groups are uncoupled. When the spiropyran absorbs UV light, it opens up to form a merocyanine because the open reaction is very efficient. In the merocyanine form, the acceptor is in a conjugated state, thus lowering the HOMO and LUMO of the merocyanine. When the electron deficient merocyanine absorbs visible light, an excited state with strong oxidizing and long lifetime is formed. An electron is transferred from the co-initiator to the merocyanine, followed by a proton transfer. The initiating radical formed thereby can initiate polymerization.

[0270] In one aspect, the intermediate state can thermally return to the initial state in the printing resin at the printing temperature. Preferably, the intermediate state can thermally return to the initial state at the printing temperature in a mechanism with one or more rate constants, wherein the highest rate constant is higher than k = 0.01 s -1 It is particularly preferred that at least one rate constant of the thermal back reaction is higher than 0.02 s -1 more preferred higher than 0.05 s -1 even more preferred higher than 0.08 s -1 most preferred higher than 0.25 s -1 but optionally not higher than 0.65 s -1 Thus, the rate constant can be in the range of 0.1 s -1 to 0.65 s -1 or can be in any other range formed by the above values.

[0271] The spiropyrans of formula (1) shown above can be used in combination with a method of locally polymerizing a starting material by two-color photopolymerization. The same applies to a 3D printing method of a shaped body or a volumetric printing method of a shaped body. A detailed description of the use of spiropyrans in formulations for two-color photopolymerization in volumetric printing can be found in the PCT application [Garmshausen et al., WO2020245456A1] which describes the successful use of spiropyrans as photoinitiators, especially two-color photoinitiators for volumetric printing.

[0272] Formulations suitable for volumetric printing can contain the following parts by weight: 1 to 99.9999 parts by weight, preferably 5 to 99.99 parts by weight, more preferably 20 to 99.9 parts by weight of a photopolymerizable compound, such as a monomer; 0 to 99 parts by weight, preferably 1 to 50 parts by weight, more preferably 3 to 20 parts by weight of a co-initiator, wherein the co-initiator contains a photopolymerizable group, such as an acrylic acid / ester; 0 to 50 wt%, preferably 1 to 40 wt%, more preferably 3 to 10 wt% of a co-initiator, wherein the co-initiator does not contain a photopolymerizable group; 0.0001 to 20 wt%, preferably 0.001 to 10 wt%, more preferably 0.01 to 5 wt%, most preferably 0.1 to 1 wt% of a spiropyran of formula (1), which can be used as a dual color photoinitiator; 0 to 20 wt%, preferably 1 to 10 wt%, more preferably 3 to 5 wt% of an acid or a base; 0 to 90 wt%, preferably 1 to 70 wt%, more preferably 5 to 50 wt%, most preferably 10 to 30 wt% of further additives, such as organic or inorganic fillers, optical brighteners, inhibitors, chain transfer agents, etc.; 0 to 90 wt%, preferably 5 to 50 wt%, more preferably 10 to 30 wt% of a solvent; and 0 to 99 wt%, preferably 5 to 95 wt%, more preferably 20 to 80 wt%, even more preferably 30 to 70 wt% of water.

[0273] All weight ratios are given relative to the weight of the total formulation.

[0274] In a preferred embodiment, the dual color photoinitiator can be lyophilized or freeze-dried before being added to the formulation.

[0275] In another preferred embodiment, the dual color photoinitiator can be precipitated as a powder before being added to the formulation by adding a solution of the dual color photoinitiator to a solvent in which the dual color photoinitiator has a lower solubility.

[0276] Typical curing parameters suitable for volumetric printing can be: any device employing two different wavelengths of light; a temperature of -20°C to +100°C, preferably 0°C to +60°C, more preferably +20°C to +60°C; a first wavelength of 250 nm to 500 nm; preferably 300 nm to 450 nm, and a second wavelength of 350 nm to 800 nm.

[0277] The co-initiator can have a high molecular weight, such as > 1000 g / mol, or be bound to a polymer to prevent migration in the cured object. The co-initiator can contain a polymerizable group, such as an acrylic acid / ester or (meth)acrylate, which is built into the polymer network during curing to prevent subsequent migration of the co-initiator. Typical examples are: .

[0278] Alternatively, the co-initiator can be a derivative of ethanolamine, preferably a derivative of diethanolamine, more preferably N-alkyldiethanolamine, or N-methyldiethanolamine, N-phenyldiethanolamine, triethanolamine, 4-(2-hydroxyethyl)morpholine, N - (2-hydroxypropyl)morpholine, N - t-butyl diethanolamine, N - butyl diethanolamine, N - (3-aminopropyl)diethanolamine, N,N - di(2-hydroxyethyl)glycine, 1-[bis(2-hydroxyethyl)amino]-2-propanol, N - phenyl diethanolamine, m-tolyl diethanolamine, p-tolyl diethanolamine, N - benzyl diethanolamine, bis(2-hydroxyethyl)aminotri(hydroxymethyl)methane, N,N - bis(2-hydroxypropyl)aniline, N,N - bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N,N - bis(2-hydroxyethyl)-3-chloroaniline, N,N,N',N' - tetra(2-hydroxyethyl)ethylenediamine, 3- N,N - bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid, N - lauryl diethanolamine, N,N, N',N' - tetra(2-hydroxypropyl)ethylenediamine, N,N,N',N",N" - penta(2-hydroxypropyl)diethylenetriamine, ethyl 4-(dimethylamino)benzoate, isoamyl 4-(dimethylamino)benzoate, 2-butoxyethyl 4-(dimethylamino)benzoate, 2-ethylhexyl 4-(dimethylamino)benzoate.

[0279] Any combination of embodiments, preferred ranges and / or parts of the present application, in particular preferred parts, is particularly preferred.

[0280] In one aspect, the present application discloses a method of locally polymerizing a starting material and forming a shaped body by two-color photopolymerization, the method comprising: providing a container at least partially filled with a polymerizable starting material containing photo-initiator molecules, the photo-initiator molecules being capable of being converted into a reactive state by a sequential photo-excitation, in which reactive state the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within the container by irradiating a first wavelength of light and a second wavelength of light different from the first wavelength into the container, thereby in the local volume, the photo-initiator molecule is transformed from the initial state, in which it absorbs substantially no light of the second wavelength, into an intermediate state having altered optical properties compared to the initial state, such that the photo-initiator molecule in the intermediate state absorbs light of the second wavelength; and the photo-initiator molecule is transformed from the intermediate state into the reactive state due to absorption of the light of the second wavelength, thereby locally triggering the polymerization to form the shaped body; wherein the extinction coefficient of the initial state of the photo-initiator in the photopolymerizable material at the first wavelength is lower than 5000 L mol -1 cm -1 , preferably lower than 2500 L mol -1 cm -1 , more preferably lower than 1000 L mol -1 cm -1 , even more preferably lower than 500 L mol -1 cm -1 , most preferably lower than 250 L mol -1 cm -1 ; and / or the extinction coefficient of the initial state of the photo-initiator in the photopolymerizable material at the first wavelength is higher than 30 L mol -1 cm -1 , preferably higher than 70 L mol -1 cm -1 , more preferably higher than 100 L mol -1 cm -1 , even more preferably higher than 150 L mol -1 cm -1 , most preferably higher than 200 L mol -1 cm -1 , such as higher than 210 L mol -1 cm -1 . Thus, the extinction coefficient of the initial state of the photo-initiator in the photopolymerizable material at the first wavelength can be in the range of 5000 to 0 L mol -1 cm -1 , preferably 2500 to 10 L mol -1 cm -1 , more preferably 1000 to 20 L mol -1 cm -1 , even more preferably 500 to 50 L mol -1 cm -1 , most preferably 300 to 100 L mol -1 cm-1 as 300 to 210 L mol -1 cm -1 .

[0281] In another aspect, the present invention discloses a method of locally polymerizing a starting material and forming a shaped body by dual color photopolymerization, the method comprising: providing a container at least partially filled with a polymerizable starting material containing photo-initiator molecules, the photo-initiator molecules being capable of being converted to a reactive state by sequential photo-excitation, in which reactive state the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within the container by irradiating light of a first wavelength and light of a second wavelength different from the first wavelength into the container, thereby in the container, the photo-initiator molecules being converted from an initial state in which the photo-initiator molecules substantially do not absorb light of the second wavelength to an intermediate state having altered optical properties compared to the initial state due to absorption of light of the first wavelength, such that the photo-initiator molecules in the intermediate state absorb light of the second wavelength; and the photo-initiator molecules being converted from the intermediate state to the reactive state due to absorption of light of the second wavelength, thereby locally triggering the polymerization to form the shaped body; wherein the optical polymerizable material has an absorbance at the first wavelength in the range of 1 to 0.05 absorbance units, preferably in the range of 1 to 0.07 absorbance units, more preferably in the range of 0.90 to 0.10 absorbance units, even more preferably in the range of 0.80 to 0.15 absorbance units, when measured at a distance of 1 cm. The absorbance of the optical polymerizable material can be measured by UV / Vis spectroscopy using a Cary 60 UV-Vis spectrophotometer provided by Agilent Technologies. Acetonitrile can be used as a reference to determine the absorbance. The first wavelength can be in the range of 250 nm to 500 nm; preferably in the range of 300 nm to 450 nm.

[0282] In another aspect, the present invention discloses a method of locally polymerizing a starting material and forming a shaped body by dual color photopolymerization, the method comprising: providing a container at least partially filled with a polymerizable starting material containing photo-initiator molecules, the photo-initiator molecules being capable of being converted to a reactive state by sequential photo-excitation, in which reactive state the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within the container by irradiating light of a first wavelength and light of a second wavelength different from the first wavelength into the container, thereby in the local volume, the photo-initiator molecule transitions from the initial state, in which it absorbs substantially no light of the second wavelength, to an intermediate state having altered optical properties compared to the initial state, such that the photo-initiator molecule in the intermediate state absorbs light of the second wavelength; and the photo-initiator molecule transitions from the intermediate state to the reactive state due to absorption of the light of the second wavelength, thereby locally triggering the polymerization to form the shaped body; wherein the extinction coefficient of the initial state of the photo-initiator in the photopolymerizable material at the first wavelength is lower than 5000 L mol -1 cm -1 , preferably lower than 2500 L mol -1 cm -1 , more preferably lower than 1000 L mol -1 cm -1 , even more preferably lower than 500 L mol -1 cm -1 , most preferably lower than 250 L mol -1 cm -1 ; and / or the extinction coefficient of the initial state of the photo-initiator in the photopolymerizable material at the first wavelength is higher than 30 L mol -1 cm -1 , preferably higher than 70 L mol -1 cm -1 , more preferably higher than 100 L mol -1 cm -1 , even more preferably higher than 150 L mol -1 cm -1 , most preferably higher than 200 L mol -1 cm -1 . Thus, the extinction coefficient of the initial state of the photo-initiator in the photopolymerizable material at the first wavelength can be in the range of 5000 to 0 L mol -1 cm -1 , preferably 3000 to 10 L mol -1 cm -1 , more preferably 2000 to 20 L mol -1 cm -1 , even more preferably 1000 to 50 L mol -1 cm -1 , most preferably 500 to 100 L mol -1 cm -1 ; and / or wherein the optical polymerizable material has an absorbance at the first wavelength in the range of 1 to 0.05 absorbance units, preferably in the range of 0.90 to 0.10 absorbance units, more preferably in the range of 0.80 to 0.15 absorbance units, when measured at a distance of 1 cm. The absorbance of the optical polymerizable material can be measured by UV / Vis spectroscopy using a Cary 60 UV-Vis spectrophotometer provided by Agilent Technologies. Acetonitrile can be used as a reference. The extinction coefficient at a specific wavelength can be calculated from the absorbance of the resin with a known concentration of photoinitiator using the same resin without photoinitiator as a reference according to the Beer-Lambert law. The first wavelength can be in the range of 250 nm to 500 nm; preferably in the range of 300 nm to 450 nm.

[0283] Using the specified extinction coefficient and absorbance units can have a surprising effect of improving the two-color effect such that hardening at the wall of the local volume, preferably the container, is minimized while ensuring a high degree of polymerization at the intersection of the first and second wavelength.

[0284] Preferably, the photoinitiator molecule is a spiropyran as disclosed in the present invention.

[0285] Preferably, the local volume can be a container.

[0286] Preferably, the container can be at least partially transparent. Thus, the container is configured to at least partially transmit the first and second wavelength from the light source into the container, whereby the polymerization reaction can be locally triggered. The container can contain a rectangular surface, preferably the container has a cuboid shape.

[0287] The container can cover a volume of at least 0.5 cm x 0.5 cm x 0.5 cm, preferably at least 1 cm x 1 cm x 1 cm, more preferably at least 1.5 cm x 1.5 cm x 1.5 cm, even more preferably at least 3 cm x 3 cm x 3 cm, most preferably at least 5 cm x 5 cm x 5 cm.

[0288] Preferably, the light of the first wavelength and the light of the second wavelength are simultaneously irradiated into the local volume.

[0289] In an alternative embodiment, the light of the second wavelength is irradiated into the local volume after the irradiation of the light of the first wavelength into the local volume has ended, while the light of the second wavelength can be irradiated before the decay time of the intermediate state of the photoinitiator molecule has ended.

[0290] Furthermore, preferably, the photoinitiator molecule in the intermediate state does not substantially absorb the light of the first wavelength.

[0291] Preferably, the extinction coefficient of the photoinitiator molecule in the initial state at the second wavelength is below 2000 L mol -1 cm -1 , more preferably below 1000 L mol -1 cm -1 , even more preferably below 500 L mol -1 cm -1 , more preferably below 200 L mol -1 cm -1 , most preferably below 100 L mol -1 cm -1 .

[0292] Preferably, the photoinitiator molecule can be converted into the reactive state due to the absorption of light of the first wavelength and the second wavelength in sequence, which can trigger polymerization in the local volume.

[0293] Preferably, the photoinitiator molecule is converted into the reactive state due to the absorption of light of the second wavelength, which can trigger free radical polymerization in the local volume.

[0294] Preferably, the light of the first wavelength is irradiated as a light beam and / or the light of the second wavelength is irradiated as a light beam. The diameter of the light beam can be 2 cm or less, preferably 1 cm or less, more preferably 0.5 cm or less, most preferably 1 mm or less. When irradiated, the light beam of the light of the first wavelength and the light beam of the light of the second wavelength can at least partially overlap in the local volume, preferably the container.

[0295] Preferably, the light of the first wavelength is irradiated as a light sheet and / or the light of the second wavelength is irradiated as a projection of a 2D image. When irradiated, the light sheet of the light of the first wavelength and the light projection of the light of the second wavelength can at least partially overlap in the local volume, preferably the container.

[0296] Preferably, the starting material is polymerized in several local volumes by photopolymerization, so that a three-dimensionally shaped body can be generated in the starting material.

[0297] Another aspect of the present application is a method for 3D printing a shaped body, wherein the shaped body is manufactured by a method as disclosed above.

[0298] 4. Low-coloring object

[0299] In volumetric 3D printing methods, it is often difficult to remove the chromophore from the interior of the printed three-dimensional object. For example, when a photoinitiator fragment or a photoinitiator radical initiates polymerization or reacts with a radical chain end, the resulting chromophore is bound to the polymer structure of the printed three-dimensional object and cannot be removed by, for example, extraction or washing.

[0300] One example of a method of how a photoinitiator radical PIH is formed from a photoinitiator PI and a co-initiator CIH is illustrated below and a co-initiator radical CI .

[0301] One example of how a co-initiator fragment CI and a photoinitiator PI form part of an exemplary acrylate polymer structure based on a radical reaction is illustrated below: .

[0302] Therefore, three-dimensional objects manufactured with a volumetric 3D printing method often have specific optical properties, i.e. absorption properties in the visible wavelength range, which lead to a colored or tinted appearance, respectively. A colored or tinted appearance of a three-dimensional object is not always desired and can actually even be unwanted for certain applications.

[0303] Therefore, there is a need to improve the method of manufacturing a three-dimensional object in order to improve the optical properties of the three-dimensional object manufactured thereby.

[0304] According to one aspect of the present application, the method of forming a shaped body by dual color photopolymerization additionally comprises the step of post-treating the shaped body, which post-treatment comprises a thermal treatment and / or an optical treatment of the shaped body.

[0305] In one embodiment, the three-dimensional object can be a shaped body or the three-dimensional object can be formed from a shaped body. Preferably, the three-dimensional object can be formed from the shaped body by taking the shaped body out of the polymerizable starting material.

[0306] In one embodiment, the post-treatment of the three-dimensional object comprises changing the optical properties of the three-dimensional object, thereby leading to a decrease of the absorption properties of the three-dimensional object at at least one wavelength in the wavelength range between 300 nm and 2000 nm, preferably between 350 nm and 1000 nm, more preferably between 400 nm and 900 nm, most preferably between 450 nm and 800 nm, and / or leading to an increase of the transmission properties of the three-dimensional object at at least one wavelength in the wavelength range between 300 nm and 2000 nm, preferably between 350 nm and 1000 nm, more preferably between 400 nm and 900 nm, most preferably between 450 nm and 800 nm.

[0307] ​In one embodiment, the post-processing of the three-dimensional object comprises changing the optical properties of the three-dimensional object such that the average transmittance or transmittance integral in the range of 300 nm to 2000 nm, preferably 350 nm to 1000 nm, more preferably 400 nm to 900 nm, most preferably 450 nm to 800 nm, is increased by at least 1 %, preferably at least 2 %, more preferably at least 3 %, more preferably at least 4 %, more preferably at least 5 %, more preferably at least 7.5 %, more preferably at least 10 %, more preferably at least 15 %, more preferably at least 20 %, more preferably at least 25 %, more preferably at least 30 %, more preferably at least 35 %, more preferably at least 40 %, more preferably at least 45 %, more preferably at least 50 %, preferably relative to the state of the three-dimensional object before it is subjected to the at least one post-processing method; and / or

[0308] The post-processing of the three-dimensional object comprises changing the optical properties of the three-dimensional object such that the average absorption or absorption integral in the range of 300 nm to 2000 nm, preferably 350 nm to 1000 nm, more preferably 400 nm to 900 nm, most preferably 450 nm to 800 nm, is decreased by at least 1 %, preferably at least 2 %, more preferably at least 3 %, more preferably at least 4 %, more preferably at least 5 %, more preferably at least 7.5 %, more preferably at least 10 %, more preferably at least 15 %, more preferably at least 20 %, more preferably at least 25 %, more preferably at least 30 %, more preferably at least 35 %, more preferably at least 40 %, more preferably at least 45 %, more preferably at least 50 %, preferably relative to the state of the three-dimensional object before it is subjected to the at least one post-processing method.

[0309] In one embodiment, the post-processing of the three-dimensional object comprises changing the optical properties of the three-dimensional object resulting in an average absorption or integral absorption per mm thickness of the three-dimensional object for a wavelength range between 300 nm to 2000 nm, preferably 350 nm to 1000 nm, more preferably 400 nm to 900 nm, most preferably 450 nm to 800 nm, of less than 0.5, preferably less than 0.3, more preferably less than 0.2, more preferably less than 0.1.

[0310] Preferably, the three-dimensional object body or the three-dimensional object has an absorption per mm thickness at each wavelength of the wavelength range between 300 nm to 2000 nm, preferably 350 nm to 1000 nm, more preferably 400 nm to 900 nm, most preferably 450 nm to 800 nm, of less than 0.5, preferably less than 0.3, more preferably less than 0.2, more preferably less than 0.1.

[0311] In one embodiment, the post-treatment comprises a thermal treatment of the three-dimensional object, the thermal treatment comprising tempering the three-dimensional object at at least one specific temperature for a specific time.

[0312] Preferably, the thermal treatment is performed in a specific time range of 0.1 minutes to 24 hours, preferably 0.5 minutes to 360 minutes, more preferably 1 minute to 60 minutes.

[0313] Preferably, the thermal treatment is performed in a specific temperature range of 50 °C to 150 °C, preferably 75 °C to 125 °C.

[0314] In one embodiment, the post-treatment comprises an optical treatment of the three-dimensional object, the optical treatment comprising irradiating the three-dimensional object with light of at least one specific wavelength for a specific time and with a specific light intensity.

[0315] Preferably, the optical treatment is performed in a time range of 0.1 minutes to 24 hours, preferably 1 minute to 360 minutes, more preferably 5 minutes to 60 minutes.

[0316] Preferably, the optical treatment of the three-dimensional object is performed with a specific light intensity, wherein the specific light intensity can be in the range of 0.0001 to 1000 W / cm 2 , preferably 0.001 to 100 W / cm 2 , more preferably 0.1 to 30 W / cm 2 , most preferably 1 to 10 W / cm 2 .

[0317] Preferably, the optical treatment is performed, wherein the at least one specific wavelength is in the range of 350 nm to 1000 nm, preferably 400 nm to 800 nm, more preferably 350 nm to 500 nm or 420 nm to 800 nm.

[0318] In one embodiment, the optical treatment is performed by irradiating light having a certain intensity and wavelength, which irradiation does not remove the three-dimensional object from the surrounding polymerizable material. Preferably, the optical treatment is performed, wherein the three-dimensional object is irradiated with light of at least one specific wavelength for a specific time and light intensity without removing it from the surrounding polymerizable material.

[0319] Preferably, the optical treatment is performed, wherein the three-dimensional object is, after irradiation with light of at least one specific wavelength for a specific time, subjected to a tempering treatment, wherein the tempering preferably comprises heating the three-dimensional object to a temperature in the range of 50 °C to 150 °C for a time in the range of 1 minute to 360 minutes, preferably 5 minutes to 60 minutes.

[0320] Claim clause

[0321] Clause (33) A method of locally polymerizing a starting material and forming a shaped body by two-color photopolymerization, the method comprising the steps of: providing a container at least partially filled with a polymerizable starting material containing photo-initiator molecules, the photo-initiator molecules being capable of being converted by sequential photo-excitation into a reactive state in which the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within the container by irradiating light of a first wavelength and light of a second wavelength different from the first wavelength into the container, wherein in the container the photo-initiator molecules are converted from an initial state in which the photo-initiator molecules do not substantially absorb light of the second wavelength to an intermediate state having altered optical properties compared to the initial state as a result of absorbing light of the first wavelength, such that the photo-initiator molecules in the intermediate state absorb light of the second wavelength; and the photo-initiator molecules are converted from the intermediate state to the reactive state as a result of absorbing light of the second wavelength, thereby locally triggering the polymerization to form the shaped body; and wherein the extinction coefficient of the initial state of the photo-initiator molecules in the photo-polymerizable material at the first wavelength is lower than 5000 L mol -1 cm -1 .

[0322] Clause (34) A method of locally polymerizing a starting material and forming a shaped body by two-color photopolymerization, the method comprising the steps of: providing a container at least partially filled with a polymerizable starting material containing photo-initiator molecules, the photo-initiator molecules being capable of being converted by sequential photo-excitation into a reactive state in which the photo-initiator molecules locally trigger polymerization of the starting material; and photopolymerizing the starting material within the container by irradiating light of a first wavelength and light of a second wavelength different from the first wavelength into the container, thereby in the container, the photo-initiator molecules are converted from an initial state in which the photo-initiator molecules do not substantially absorb light of the second wavelength to an intermediate state having altered optical properties compared to the initial state as a result of absorbing light of the first wavelength, such that the photo-initiator molecules in the intermediate state absorb light of the second wavelength; and the photo-initiator molecules are converted from the intermediate state to the reactive state as a result of absorbing light of the second wavelength, thereby locally triggering the polymerization to form the shaped body; wherein the absorbance of the photopolymerizable material at the first wavelength is in the range of 1 to 0.07 absorbance units.

[0323] Article (35) The method of article (33) or (34), wherein the photoinitiator molecule is a spiropyran as defined in the specification.

[0324] Examples

[0325] Hereinafter, the effects and advantages of the present application will be described in detail through specific examples of the present application. However, the provided examples are only for illustration of the present application, and the scope of the present application is not limited thereto.

[0326] A. Synthesis

[0327] General synthesis methods

[0328] Method A (reaction of indolenium salt or corresponding 2-methyleneindolinium with salicylaldehyde, examples 1 to 12, 35 to 43, 51, 52, 79, 86)

[0329] Dissolve 2-methyleneindolinium (1 mmol), the corresponding salicylaldehyde derivative (1 mmol) and piperidine (0.1 mmol) in 10 mL of EtOH and heat to 70°C until no more spiropyran derivative is observed, usually 1 to 12 hours. Cool the mixture to room temperature and work up as described below.

[0330] When indolenium salt derivatives are used instead of 2-methyleneindolinium, the reaction is carried out with 1.1 mmol of piperidine.

[0331] When the product precipitates, filter the mixture and recrystallize the solid residue from ethanol.

[0332] When the spiropyran is insoluble in water, add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Crystallize the residue or purify by column chromatography on silica gel using a mixture of petroleum ether-acetone.

[0333] When the spiropyran is soluble in water, the reaction mixture is directly subjected to C-18 functionalized silica gel treatment and purified by MPLC using a mixture of methanol-water. After evaporation of the solvent, the product can be dissolved in acetonitrile or methanol and ion exchange resin is added. Shake the mixture on a shaker for 1 to 3 hours and filter. Repeat the last step until the exchange is complete. Remove the solvent under reduced pressure to produce the product spiropyran derivative.

[0334] Method B (modification of halospirooxazines, examples 18 to 31, 33, 34, 61, 84, 85, 88)

[0335] The halospirooxazine (1.5 mmol) was dissolved in dry tetrahydrofuran (25 mL) under an argon atmosphere and cooled to -78°C. n-Butyllithium (1.65 mmol, 2.5 M in hexane) was added dropwise. After stirring at -78°C for 15 minutes, the reaction mixture was allowed to warm to room temperature. The reaction was stirred until no further conversion was observed, 1 M aqueous hydrochloric acid (10 mL) was added. The mixture was stirred for 10 minutes, 1 M aqueous NaOH (20 mL) was added and the mixture was extracted with ethyl acetate. The combined organic layers were dried over anhydrous MgS04and evaporated under reduced pressure. The residue was crystallized or purified by column chromatography on silica gel using a mixture of petroleum ether-acetone.

[0336] For derivative 34, glutaric anhydride was used instead of vanillylic amide and the reaction mixture was neutralized before extraction.

[0337] For derivative 19, 2-dimethylamino-2-methylpropionitrile was used instead of vanillylic amide.

[0338] For derivatives 31 and 91, the reaction was performed with 2.2 equivalents of n-butyllithium and 2.8 equivalents of vanillylic amide.

[0339] Method C (reaction of indolium salts with catalytic amounts of base, examples 15 to 17, 44 to 50, 54 to 60, 62 to 66, 80 to 83)

[0340] The indolium salt derivative (1.2 mmol), the spirooxazine derivative (1 mmol) and piperidine (0.1 mmol) were dissolved in 20 mL of ethanol and stirred at 70°C until no more product spirooxazine derivative was observed, usually between 30 minutes and 12 hours. The reaction mixture was cooled to room temperature and worked up as described below.

[0341] When the product precipitates, the mixture is filtered and the solid residue is recrystallized from ethanol.

[0342] When the spirooxazine is not soluble in water, water and ethyl acetate were added to the mixture and the organic phase was washed with water. The organic phase was dried over anhydrous MgS04and evaporated under reduced pressure. The residue was crystallized or purified by column chromatography on silica gel using a mixture of petroleum ether-acetone.

[0343] When the spiropyrans are dissolved in water, the reaction mixture is directly subjected to C-18 functionalized silica gel treatment and purified by MPLC using a mixture of methanol-water. After evaporation of the solvent, the product can be dissolved in acetonitrile or methanol and ion exchange resin added. The mixture is left on a shaker for 1 to 3 hours and filtered. The last step is repeated until the exchange is complete. The solvent is removed under reduced pressure to yield the product spiropyrane derivative.

[0344] In all reactions according to Method C, also the corresponding 2-methyleneindolin is obtained. In reactions where the 2-methyleneindolin is the desired product, the reaction can be carried out as follows: 1,3,3-trimethyl-5-nitro-2-methyleneindolin or the corresponding indolinium salt (1.2 mmol), the spiropyrane derivative (1 mmol), piperidine (0.1 mmol) and acetic acid (1 mL) are dissolved in 20 mL ethanol and stirred at 70 °C until no more product 2-methyleneindolin derivative is observed, typically 30 minutes to 12 hours. Purification is carried out as outlined above.

[0345] Synthesis of 56: 73 (2.1 mmol), 26 (1 mmol) and piperidine (2 mmol) are dissolved in 20 mL ethanol and stirred at 70 °C for 24 hours. The reaction mixture is cooled to room temperature, water and ethyl acetate are added to the mixture and the organic phase is washed with water. The organic phase is dried over anhydrous MgS04and evaporated under reduced pressure. The residue is purified by column chromatography on silica gel using a mixture of petroleum ether-acetone to yield the intermediate 87. The intermediate 87 is dissolved in ethanol (10 mL) and acetic acid (1 mL). The mixture is stirred for 12 hours. 1 M aqueous NaOH and ethyl acetate are added and the mixture is washed with 1 M aqueous NaOH and water. The combined organic phases are dried over anhydrous MgS04and evaporated under reduced pressure. The residue is purified by column chromatography on silica gel using a mixture of petroleum ether-acetone to yield the product 56.

[0346] Method D (synthesis of indolinium salts from corresponding indoles, examples 67 to 78)

[0347] The corresponding aniline derivative (50 mmol) is dissolved in a mixture of concentrated aqueous hydrochloric acid (20 mL) and ice water (30 mL). At 0 °C, NaNCte (100 mmol) in water is added. After stirring for 30 minutes, SnCl2(28.4 g) in concentrated aqueous hydrochloric acid (35 mL) is added. The resulting mixture is stirred for 30 minutes, filtered, washed with water or 1 M aqueous hydrochloric acid to yield the hydrazine hydrochloride which can be used directly in the next step.

[0348] The appropriate hydrazine (as the hydrochloride salt) (47.5 mmol), 3-methylbutan-2-one and concentrated aqueous sulphuric acid (7 mL) were dissolved in glacial acetic acid (68 mL). The mixture was refluxed until no more indole was observed to be formed. The mixture was allowed to cool to room temperature and worked up as described below.

[0349] When the product is not functionalised with a water-soluble group, most of the acetic acid is removed by distillation. The residue is neutralised with saturated aqueous NaHCO3. The mixture is extracted with ethyl acetate and the combined organic phases are dried over anhydrous MgSO4and the solvent is evaporated under reduced pressure. When the purity of the indole is insufficient for the next step, column chromatography on silica gel using a mixture of petroleum ether / acetone as eluent is used.

[0350] When the product is functionalised with a water-soluble group, ethyl acetate (1 L) is added to the mixture. After complete precipitation, the mixture is filtered and the indole is used directly in the next step. When the purity of the indole is insufficient, it can be purified by MPLC using a water-methanol solvent mixture.

[0351] The indole derivative obtained (30 mmol) is dissolved in acetonitrile (150 mL) and the appropriate alkyl halide or propane sultine (90 mmol) is added. The mixture is refluxed for 24 hours. After cooling to room temperature, the product is precipitated, filtered and washed with acetonitrile. If the product does not precipitate, the solvent is evaporated under reduced pressure. The indole is purified by recrystallisation from a mixture of acetonitrile, acetone and ethyl acetate.

[0352] If the reactivity of the indole is insufficient to form the product described above in the procedure described above, the procedure is modified as follows: the indole derivative (30 mmol) is dissolved in N,N-dimethylformamide (150 mL) and the appropriate alkyl halide or propane sultine (90 mmol) is added. The mixture is heated to 120°C. After observing that no more product is formed, the reaction is cooled to room temperature and ethyl acetate (1 L) is added. After complete precipitation, the product is filtered and washed with ethyl acetate. The product is recrystallised from a mixture of acetonitrile-ethyl acetate.

[0353] If the indole is required, the appropriate indolenium salt is dissolved in a mixture of ethyl acetate and 1 M aqueous NaOH. The mixture is extracted with ethyl acetate. The combined organic layers are dried over anhydrous MgSO4and evaporated under reduced pressure to yield the indole derivative.

[0354] Exchange of the two spiropyrans

[0355] Dissolve 43 (1 mmol) and 51 (1 mmol) in ethanol (5 mL) containing 1% acetic acid and stir at 70 °C for 7 days. Add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone to yield 12 and 13.

[0356] Dissolve 43 (1 mmol), 51 (1 mmol), 71 (0.1 mmol) and piperidine (0.1 mmol) in ethanol (5 mL) and stir at 70 °C for 24 hours. Add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone to yield 12 and 13.

[0357] Dissolve 89 (1 mmol), 90 (1 mmol) and 1,3,3-trimethyl-2-methylene-indolin (0.1 mmol) in ethanol (10 mL) and stir at 70 °C for 7 days. Add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone to yield 14 and the unsubstituted spiropyran.

[0358] Pre-activation of spiropyrans with a base and reaction with salicylaldehyde

[0359] Dissolve 18 (1 mmol) and methylamine (0.1 mmol) in n-butanol (20 mL) and water (2 mL) and heat to 120 °C for 48 hours. Cool the mixture to room temperature and add 1 M aqueous hydrochloric acid (10 mL). Stir the mixture for 10 minutes, add 1 M aqueous NaOH (20 mL) and ethyl acetate. Separate the organic phase, wash once with 1 M aqueous NaOH and once with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. The residue can be used directly in the next reaction. In cases where separation is difficult in the next reaction, purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone. Dissolve the pre-activated 15 (1 mmol) in ethanol (10 mL), add 3-formyl-4-hydroxybenzoic acid methyl ester (1 mmol) and piperidine (0.1 mmol). Stir the reaction at 70 °C for 24 hours. Cool the reaction mixture to room temperature, add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone to yield 32.

[0360] Dissolve 85 (1 mmol) and methylamine (0.1 mmol) in ethanol (20 mL) and heat to 70 °C for 24 hours. Cool the mixture to room temperature and add 1 M aqueous hydrochloric acid (10 mL). Stir the mixture for 10 minutes, add 1 M aqueous NaOH (20 mL) and ethyl acetate. Separate the organic phase, wash once with 1 M aqueous NaOH and once with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Dissolve the residue in ethanol (10 mL), add methyl 3-formyl-4-hydroxybenzoate (1 mmol) and piperidine (0.1 mmol). Stir the reaction at 70 °C for 24 hours. Cool the reaction mixture to room temperature, add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone to yield 86.

[0361] Knoevenagel condensation of spiropyrans

[0362] Dissolve 38 (1 mmol), malononitrile (1 mmol) and piperidine (0.1 mmol) in ethanol (25 ml) and stir at room temperature for 2 hours. Add water and ethyl acetate to the mixture and wash the organic phase with water. Dry the organic phase over anhydrous MgS04and evaporate under reduced pressure. Purify the residue by silica gel column chromatography using a mixture of petroleum ether-acetone to yield 53.

[0363] Numbering scheme for spiropyrans and indolium salts .

[0364] As non-limiting examples, the following spiropyrans and indolium salts, 2-methyleneindoliniums have been prepared by following the prescribed procedures:

[0365] 1 H-NMR data

[0366] The methylene of the free Fieser base and indolium salt is exchanged in deuterated methanol and therefore not visible.

[0367] 1 1 H NMR (300 MHz, Chloroform-d d 2) δ 7.23 7.10 (m, 3H), 7.06 (m, 1H), 6.886.77 (m, 2H), 6.60 (d,J = 8.1 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.76 (d, J = 10.3 Hz, 1H), 2.71 (s, 3H), 1.28 (s, 3H), 1.15 (s, 3H).

[0368] 4 1 H NMR (300 MHz, Methanol-d4) δ 7.32 (dd, d 2) δ 7.22 (s, 1H), 7.20 7.11 (m, 1H), 7.117.04 (m, 1H), 6.90 6.74 (m, 2H), 6.52 (dt, J = 8.0, 1.5 Hz, 1H), 7.17 (td, J = 7.6, 1.3 Hz, 1H), 7.12 7.01 (m, 2H), 6.90 6.80 (m, 2H), 6.73 (dd, J = 8.0, 7.5 Hz, 1H), 6.60 6.49 (m, 1H), 5.74 (d, J = 10.2 Hz, 1H), 2.72 (s, 3H), 1.30 (s, 3H), 1.16 (s, 3H).

[0369] 5 1 H NMR (300 MHz, Methanol-d4) δ 7.32 (dd, d 2) δ 7.22 (s, 1H), 7.20 7.11 (m, 1H), 7.117.04 (m, 1H), 6.90 6.74 (m, 2H), 6.52 (dt, J = 7.7, 0.7 Hz, 1H), 6.38 (d, J = 0.6 Hz, 1H), 5.61 (d, J = 10.2 Hz, 1H), 3.76 (s, 3H), 2.72 (s, 3H), 1.29 (s, 3H), 1.15 (s, 3H).

[0370] 9 1 H NMR (300 MHz, Methanol-d4) δ 7.32 (dd, d 2) δ 7.22 (s, 1H), 7.20 7.11 (m, 1H), 7.117.04 (m, 1H), 6.90 6.74 (m, 2H), 6.52 (dt, J = 2.5 Hz, 1H), 7.33 (d, J = 1.8 Hz, 1H), 6.88 (d, J = 10.4 Hz, 1H), 6.33 (d, J = 8.1 Hz, 1H), 5.84 (d,J = 10.4 Hz, 1H), 2.65 (s, 3H), 1.27 (s, 3H), 1.17 (s, 3H).

[0371] 11 1 H NMR (500 MHz, Chloroform- d ) δ 7.35 (ddd, J = 8.5, 2.3, 0.8 Hz, 1H), 7.31 (d, J = 2.2 Hz, 1H), 7.27 (dd, J = 8.2, 2.0 Hz, 1H), 7.15 (d, J = 2.0 Hz, 1H), 6.89 (dd, J = 10.4, 0.7 Hz, 1H), 6.77 (d, J = 8.5 Hz, 1H), 6.41 (d, J = 8.2 Hz, 1H), 5.75 (d, J = 10.3 Hz, 1H), 2.70 (s, 3H), 1.27 (s, 3H), 1.17 (s, 3H).

[0372] 12 1 H NMR (500 MHz, Chloroform- d 2) δ 7.78 7.73 (m, 3H), 7.56 (d, J = 1.9 Hz, 1H), 7.00 (dd, J = 10.4, 0.7 Hz, 1H), 6.74 (dt, J = 8.2, 0.7 Hz, 1H), 6.62 (d, J = 8.3 Hz, 1H), 5.77 (d, J = 10.3 Hz, 1H), 3.03 (s, 3H), 2.82 (s, 3H), 2.51 (s, 3H), 1.32 (s, 3H), 1.20 (s, 3H).

[0373] 13 1 H NMR (500 MHz, Chloroform- d 2) δ 7.72 (dd, J = 8.4, 3.1, 4H), 7.70 (d, J= 8.0 Hz, 2H), 7.68 7.52 (m, 3H), 7.50 7.42 (m, 4H), 6.96 (dd, J = 10.4, 0.7 Hz, 1H), 6.79 (dd, J = 8.2, 1.0 Hz, 1H), 6.60 (dd, J = 8.0, 0.8 Hz, 1H), 5.80 (d, J = 10.1 Hz, 1H), 2.86 (s, 3H), 1.36 (s, 3H), 1.23 (s, 3H).

[0374] 14 1 H NMR (500 MHz, Methanol-d4) δ 8.01 (d, d 2) 7.80 7.72 (m, 4H), 7.71 (d, J = 7.8 Hz, 2H), 7.68 7.60 (m, 2H), 7.57 7.51 (m, 2H), 7.49 (d, J = 7.5 Hz, 4H), 6.98 (d, J = 10.4 Hz, 1H), 6.79 (d, J = 8.2, 1H), 6.58 (dd, J = 8.1, 0.9 Hz, 1H), 5.76 (d, J = 10.2 Hz, 1H), 2.87 (s, 3H), 1.37 (s, 3H), 1.22 (s, 3H).

[0375] 18 1 H NMR (500 MHz, Methanol-d4) δ 8.01 (d, d 2) 7.80 7.72 (m, 4H), 7.71 (d, J = 1.8 Hz, 1H), 7.58 (dd, J = 8.2, 1.8 Hz, 1H), 7.56 7.46 (m, 4H), 7.13 (ddd, J = 8.1, 7.3, 1.7 Hz, 1H), 7.09 (dd, J = 7.5, 1.7 Hz, 1H), 6.92 (dd, J = 10.2, 0.7 Hz, 1H), 6.86 (td, J = 7.4, 1.1 Hz, 1H), 6.72 (dt,J = 8.1, 0.9 Hz, 1H), 6.44 (d, J =8.2 Hz, 1H), 5.69 (d, J = 10.2 Hz, 1H), 2.81 (s, 3H), 1.32 (s, 3H), 1.19 (s, 3H).

[0376] 19 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.24 7.01 (m, 3H), 7.00 6.76 (m, 2H), 6.75 6.62 (m, 1H), 6.62 6.47 (m, 2H), 5.82 5.67 (m, 1H), 2.74 (s, 3H), 2.23 (s, 6H), 1.29 (s, 3H), 1.25 (s, 6H), 1.17 (s, 3H).

[0377] 20 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.80 7.68 (m, 2H), 7.61 7.52 (m, 1H), 7.51 7.42 (m, 2H), 7.30 (dd, J = 7.8, 1.6 Hz, 1H), 7.25 7.10 (m, 3H), 7.10 7.04 (m, 1H), 6.97 (dd, J = 10.3, 0.8 Hz, 1H), 6.82 (td, J = 7.4, 1.0 Hz, 1H), 6.57 6.50 (m, 1H), 5.87 (d, J = 10.3 Hz, 1H), 2.75 (s, 3H), 1.32 (s, 3H), 1.18 (s, 3H).

[0378] twenty one 1 H NMR (300 MHz, dichloromethane- d 2) δ 7.87 7.79 (m, 2H), 7.76 7.69 (m, 2H), 7.32 (dd, J = 7.8, 1.6 Hz, 1H), 7.22 (d, J = 7.8 Hz, 1H), 7.15 (td, J = 7.6, 1.3 Hz, 1H), 7.11 7.04 (m, 2H), 6.98 (dd, J= 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H).

[0379] 22 1 H NMR (300 MHz, Chloroform-d d 2) δ 7.61 (ddd, J = 7.9, 1.7, 0.3 Hz, 1H), 7.25 (dd, J = 7.7, 1.3 Hz, 1H), 7.16 (td, J = 7.7, 1.3 Hz, 1H), 6.97 (d, J = 7.7 Hz, 1H), 6.92 (d, J = 7.7 Hz, 1H), 6.54 (d, J = 10.3 Hz, 1H), 5.85 (d, J = 10.3 Hz, 1H), 2.72 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H).

[0380] 23 1 H NMR (300 MHz, Chloroform-d d 2) δ 7.61 (ddd, J = 7.9, 1.7, 0.3 Hz, 1H), 7.25 (dd, J = 7.7, 1.3 Hz, 1H), 7.16 (td, J = 7.7, 1.3 Hz, 1H), 6.97 (d, J = 7.7 Hz, 1H), 6.92 (d, J = 7.7 Hz, 1H), 6.54 (d, J = 10.3 Hz, 1H), 5.85 (d, J = 10.3 Hz, 1H), 2.72 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H). J = 7.4, 1.0 Hz, 1H), 6.52 (dd, J = 7.8, 0.8 Hz, 1H), 5.89 (d, J = 10.3 Hz, 1H), 2.74 (s, 3H), 1.30 (s, 3H), 1.18 (s, 3H).

[0381] 24 1 H NMR (300 MHz, Chloroform-d d 2) δ 7.61 (ddd, J= 7.8, 1.7 Hz, 1H), 7.337.27 (m, 1H), 7.23 7.14 (m, 2H), 7.09 (ddd, J = 7.3, 1.3, 0.6 Hz, 1H), 6.95 (dd, J =10.3, 0.8 Hz, 1H), 6.85 (td, J = 7.4, 1.0 Hz, 1H), 6.58 6.51 (m, 1H), 5.86 (d, J = 10.2Hz, 1H), 2.73 (s, 3H), 2.48 (s, 3H), 1.31 (s, 3H), 1.18 (s, 3H).

[0382] 25 1 H NMR (300 MHz, dichloromethane- d 2) δ 7.66 (dd, J = 10.7, 0.8 Hz, 1H), 7.27(dd, J = 7.7, 1.2 Hz, 1H), 7.23 7.11 (m, 2H), 7.11 7.03 (m, 1H), 6.92 6.79 (m, 2H), 6.55 6.47 (m, 1H), 5.81 (d, J = 10.7 Hz, 1H), 2.72 (s, 3H), 2.58 (s, 3H), 1.28 (s, 3H), 1.16 (s, 3H).

[0383] 26 1 H NMR (300 MHz, dichloromethane- d 2) δ 7.48 7.36 (m, 3H), 7.28 7.15 (m, 4H), 7.01 (td, J = 7.6, 1.3 Hz, 1H), 6.96 6.88 (m, 2H), 6.88 6.80 (m, 1H), 6.70 (td, J =7.4, 1.0 Hz, 1H), 6.24 (dd, J = 7.7, 0.8 Hz, 1H), 5.70 (d, J = 10.3 Hz, 1H), 2.55 (s, 3H), 1.07 (s, 3H), 1.05 (s, 3H).

[0384] 27 1 H NMR (300 MHz, dichloromethane- d2) δ 7.79 7.70 (m, 2H), 7.60 7.51 (m, 1H), 7.50 7.39 (m, 2H), 7.24 7.06 (m, 3H), 6.91 6.79 (m, 2H), 6.59 6.53 (m, 1H), 6.40 (d, J = 10.2 Hz, 1H), 3.58 (s, 3H), 2.77 (s, 3H), 1.34 (s, 3H), 1.18 (s, 3H). J = 10.2 Hz, 1H), 3.58 (s, 3H), 2.77 (s, 3H), 1.34 (s, 3H), 1.18 (s, 3H).

[0385] 28 1 H NMR (300 MHz, Methanol-d4 at 298 K) d 2) δ 7.76 7.65 (m, 2H), 7.60 7.51 (m, 1H), 7.49 7.40 (m, 2H), 7.29 (dd, J = 7.8, 1.6 Hz, 1H), 7.19 (d, J = 7.8 Hz, 1H), 7.13 7.07 (m, 1H), 6.95 (dd, J = 10.3, 0.8 Hz, 1H), 6.73 6.61 (m, 2H), 6.48 6.38 (m, 1H), 5.86 (d, J = 10.2 Hz, 1H), 3.58 (s, 3H), 2.77 (s, 3H), 1.34 (s, 3H), 1.18 (s, 3H).

[0386] 29 1 H NMR (500 MHz, Methanol-d4 at 298 K) d 2) δ 8.01 7.97 (m, 1H), 7.89 (d, J = 2.1 Hz, 1H), 7.18 (td, J = 7.7, 1.3 Hz, 1H), 7.09 (ddd, J = 7.3, 1.3, 0.5 Hz, 1H), 7.01 (d, J = 10.4 Hz, 1H), 6.88 (td, J = 7.4, 1.0 Hz, 1H), 6.55 (dt, J = 7.8, 0.7 Hz, 1H), 5.90 (d, J= 10.4 Hz, 1H), 2.69 (s, 3H), 2.54 (s, 3H), 1.31 (s, 3H), 1.20 (s, 3H).

[0387] 30 1 H NMR (500 MHz, Methanol-d4, d 2) δ 7.85 7.80 (m, 2H), 7.74 7.70 (m, 2H), 7.32 (dd, J = 7.8, 1.6 Hz, 1H), 7.22 (d, J = 7.8 Hz, 1H), 7.15 (td, J = 7.7, 1.3 Hz, 1H), 7.10 (dd, J = 1.7, 0.7 Hz, 1H), 7.06 (ddd, J = 7.2, 1.3, 0.6 Hz, 1H), 6.98 (dd, J = 10.2, 0.7 Hz, 1H), 6.82 (td, J = 7.4, 1.0 Hz, 1H), 6.52 (dt, J = 7.8, 0.7 Hz, 1H), 5.89 (d, J = 10.2 Hz, 1H), 2.74 (s, 3H), 1.31 (s, 3H), 1.18 (s, 3H).

[0388] 31 1 H NMR (300 MHz, Methanol-d4, d 2) δ 7.96 7.89 (m, 1H), 7.81 (d, J = 2.2 Hz, 1H), 7.79 7.68 (m, 6H), 7.67 7.59 (m, 1H), 7.59 7.37 (m, 5H), 7.04 (d, J = 10.5 Hz, 1H), 6.58 (d, J = 8.6 Hz, 1H), 5.92 (d, J = 10.4 Hz, 1H), 2.82 (s, 3H), 1.39 (s, 3H), 1.26 (s, 3H).

[0389] 32 1 H NMR (500 MHz, Methanol-d4, d 2) δ 8.06 7.91 (m, 2H), 7.88 (d,J = 1.7 Hz, 1H), 7.83 7.78 (m, 1H), 7.69 (dd, J = 8.2, 1.8 Hz, 1H), 7.59 (dd, J = 8.2, 1.8 Hz, 1H), 7.57 7.46 (m, 3H), 7.40 (t, J = 2.2 Hz, 1H), 7.16 (dd, J = 8.6, 2.5 Hz, 1H), 6.97 (dd, J = 10.3, 0.7 Hz, 1H), 6.85 (d, J = 8.2 Hz, 1H), 6.78 6.74 (m, 1H), 6.46 (d, J = 8.2Hz, 1H), 5.77 (d, J = 10.3 Hz, 1H), 3.85 (s, 3H), 2.81 (s, 3H), 1.35 (s, 3H), 1.26 (s, 3H).

[0390] 33 1 H NMR (500 MHz, Methanol-d4, d 2) δ 7.81 7.75 (m, 2H), 7.61 7.54 (m, 2H), 7.23 7.13 (m, 3H), 7.08 (ddd, J = 7.3, 1.4, 0.5 Hz, 1H), 6.94 (dd, J = 10.3, 0.7 Hz, 1H), 6.85 (td, J = 7.4, 1.0 Hz, 1H), 6.77 (dt, J = 8.3, 0.7 Hz, 1H), 6.55 (dt, J = 7.8, 0.7 Hz, 1H), 5.81 (d, J = 10.3 Hz, 1H), 2.75 (s, 3H), 1.31 (s, 3H), 1.18 (s, 3H).

[0391] 34 1 H NMR (500 MHz, Methanol-d4, d 4) δ 7.46 (dd, J = 7.9, 1.7 Hz, 1H), 7.24 (d, J =1.6 Hz, 1H), 7.22 (d,J = 7.9 Hz, 1H), 7.12 (td, J = 7.7, 1.3 Hz, 1H), 7.05 (dd, J =7.3, 1.2 Hz, 1H), 7.01 (dd, J = 10.3, 0.7 Hz, 1H), 6.80 (td, J = 7.4, 1.0 Hz, 1H), 6.53(d, J = 7.7 Hz, 1H), 5.92 (d, J = 10.2 Hz, 1H), 2.98 2.94 (m, 2H), 2.70 (s, 3H), 2.562.22 (m, 2H), 1.95 1.78 (m, 2H), 1.28 (s, 3H), 1.15 (s, 3H).

[0392] 35 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.82 7.66 (m, 4H), 7.62 7.39 (m, 5H), 6.93 (dd, J = 10.4, 0.7 Hz, 1H), 6.87 6.77 (m, 1H), 6.64 6.54 (m, 1H), 5.84 (d, J =10.3 Hz, 1H), 2.83 (s, 3H), 1.32 (s, 3H), 1.21 (s, 3H).

[0393] 36 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.76 (dd, J = 8.3, 1.9 Hz, 1H), 7.56 (d, J = 1.9 Hz, 1H), 7.46 7.36 (m, 2H), 6.97 6.91 (m, 1H), 6.80 6.74 (m, 1H), 6.62 (d, J =8.3 Hz, 1H), 5.82 (d, J = 10.3 Hz, 1H), 3.02 (s, 3H), 2.81 (s, 3H), 1.32 (s, 3H), 1.19 (s, 3H).

[0394] 37 1 H NMR (300 MHz, dichloromethane-) d2) δ 7.81 (m, 2H), 7.77 7.65 (m, 4H), 7.60 7.53 (m, 1H), 7.52 7.44 (m, 2H), 6.98 (dd, J = 10.4, 0.7 Hz, 1H), 6.75 (dd, J = 9.1, 0.7 Hz, 1H), 6.60 6.50 (m, 1H), 5.78 (d, J = 10.3 Hz, 1H), 3.85 (s, 3H), 2.83 (s, 3H), 1.33 (s, 3H), 1.20 (s, 3H).

[0395] 38 1 H NMR (300 MHz, Methanol-d4 at 298 K) d 2) δ 9.84 (s, 1H), 7.81 7.63 (m, 6H), 7.62 7.53 (m, 1H), 7.53 7.45 (m, 2H), 7.02 (dd, J = 10.3, 0.7 Hz, 1H), 6.89 6.81 (m, 1H), 6.57 (dd, J = 7.8, 0.9 Hz, 1H), 5.83 (d, J = 10.3 Hz, 1H), 2.84 (s, 3H), 1.33 (s, 3H), 1.22 (s, 3H).

[0396] 39 1 H NMR (300 MHz, Methanol-d4 at 298 K) d 4) δ 7.88 7.80 (m, 2H), 7.75 7.57 (m, 5H), 7.57 7.47 (m, 2H), 7.10 (dd, J = 10.4, 0.7 Hz, 1H), 6.87 6.72 (m, 2H), 5.96 (d, J = 10.3 Hz, 1H), 3.58 3.37 (m, 2H), 2.83 (ddd, J = 8.0, 6.8, 3.1 Hz, 2H), 2.55 (s, 3H), 2.21 2.02 (m, 2H), 1.32 (s, 3H), 1.22 (s, 3H).

[0397] 40 1 H NMR (300 MHz, Methanol-d4 at 298 K) d 2) δ 7.75 7.73 (m, 1H), 7.73 (d,J = 1.5 Hz, 1H), 7.71 (dd, J = 8.1, 1.8 Hz, 1H), 7.68 (dd, J = 1.8, 0.5 Hz, 1H), 7.60 7.55 (m, 1H), 7.52 7.47 (m, 2H), 7.44 (dt, J = 1.5, 0.8 Hz, 1H), 7.27 (ddt, J = 10.7, 2.9, 1.9 Hz, 1H), 7.24 7.21 (m, 1H), 6.58 (d, J = 8.1 Hz, 1H), 6.04 (d, J = 10.7 Hz, 1H), 2.84 (s, 3H), 1.35 (s, 3H), 1.23 (s, 3H).

[0398] 41 1 H NMR (500 MHz, dichloromethane-) d 2) δ 7.73 (t, J = 1.4 Hz, 1H), 7.72 (d, J =1.5 Hz, 1H), 7.69 (dd, J = 8.2, 1.8 Hz, 1H), 7.67 7.66 (m, 1H), 7.60 7.53 (m, 1H), 7.537.44 (m, 2H), 7.25 (dd, J = 10.5, 0.8 Hz, 1H), 6.95 (d, J = 2.0 Hz, 1H), 6.69 (dd, J =2.0, 0.8 Hz, 1H), 6.55 (d, J = 8.1 Hz, 1H), 5.84 (d, J = 10.5 Hz, 1H), 2.82 (s, 3H), 1.32 (s, 3H), 1.20 (s, 3H).

[0399] 42 1 H NMR (500 MHz, dichloromethane-) d 2) δ 10.16 (s, 1H), 9.90 (s, 1H), 8.14 (d, J =2.1 Hz, 1H), 7.88 (d, J= 2.1 Hz, 1 H), 7.77 7.72 (m, 2H), 7.72 7.69 (m, 2H), 7.59 7.55 (m, 1 H), 7.53 7.45 (m, 2H), 7.08 (d, J = 10.5 Hz, 1 H), 6.60 (d, J = 8.7 Hz, 1 H), 5.95 (d, J = 10.5 Hz, 1 H), 2.88 (s, 3H), 1.35 (s, 3H), 1.29 (s, 3H).

[0400] 43 1H NMR (500 MHz, Methanol-d4) δ 7.78 7.72 (m, 4H), 7.71 7.67 (m, 2H), 7.59 7.55 (m, 1 H), 7.51 7.47 (m, 2H), 6.99 (dd, J = 10.3, 0.7 Hz, 1 H), 6.77 (dt, J = 8.3, 0.7 Hz, 1 H), 6.58 6.53 (m, 1 H), 5.79 (d, J = 10.3 Hz, 1 H), 2.84 (s, 3H), 2.51 (s, 3H), 1.33 (s, 3H), 1.21 (s, 3H).

[0401] 44 1 H NMR (300 MHz, Methanol- d 4) δ 7.88 (d, J = 8.5 Hz, 2H), 7.82 (d, J = 8.0 Hz, 2H), 7.42 (d, J = 8.6 Hz, 1 H), 7.32 7.22 (m, 2H), 7.17 7.05 (m, 3H), 5.96 (d, J = 10.4 Hz, 1 H), 3.18 (s, 3H), 1.63 (s, 3H), 1.36 (s, 3H).

[0402] 45 1 H NMR (300 MHz, Methanol- d 4) δ 8.28 (d, J = 1.9 Hz, 1 H), 8.00 (d, J = 8.9 Hz, 1 H), 7.85 (d, J = 8.5 Hz, 1 H), 7.80 (dd, J= 9.0, 1.9 Hz, 1H), 7.75 7.69 (m, 1H), 7.62 7.55 (m, 1H), 7.48 (t, J = 7.4 Hz, 1H), 7.30 (d, J = 7.7 Hz, 1H), 7.25 (dd, J =7.8, 1.6 Hz, 1H), 7.17 7.04 (m, 1H), 6.04 (d, J = 10.3 Hz, 1H), 3.11 (s, 3H), 2.89 (s, 3H), 1.66 (s, 3H), 1.36 (s, 3H).

[0403] 47 1 H NMR (300 MHz, methanol-) d 4) δ 7.76 7.54 (m, 8H), 7.54 7.43 (m, 4H), 7.347.21 (m, 2H), 7.15 7.02 (m, 2H), 6.78 (d, J = 8.8 Hz, 1H), 6.03 (d, J = 10.2 Hz, 1H), 3.62 3.34 (m, 2H), 2.94 2.75 (m, 2H), 2.25 2.01 (m, 2H), 1.33 (s, 3H), 1.22 (s, 3H).

[0404] 49 1 H NMR (300 MHz, dichloromethane- d 2) δ 7.80 7.66 (m, 4H), 7.63 7.54 (m, 1H), 7.53 7.43 (m, 3H), 7.35 7.25 (m, 1H), 7.20 (d, J = 7.9 Hz, 1H), 6.98 (dd, J = 10.3, 0.8 Hz, 1H), 6.55 (dd, J = 7.8, 0.8 Hz, 1H), 5.86 (d, J = 10.2 Hz, 1H), 2.83 (s, 3H), 2.49 (s, 3H), 1.35 (s, 3H), 1.21 (s, 3H).

[0405] 50 1 H NMR (300 MHz, dichloromethane- d2) δ 7.84 7.66 (m, 2H), 7.56 (m, 1H), 7.51 7.39 (m, 2H), 7.36 7.24 (m, 2H), 7.23 7.15 (m, 1H), 7.16 7.08 (m, 1H), 6.97 (dd, J = 10.3, 0.8 Hz, 1H), 6.33 (d, J = 8.3 Hz, 1H), 5.83 (d, J = 10.2 Hz, 1H), 2.72 (s, 3H), 1.28 (s, 3H), 1.17 (s, 3H).

[0406] 51 1 H NMR (500 MHz, Methanol-d4, d 2) δ 7.83 7.73 (m, 3H), 7.63 7.54 (m, 3H), 7.24 7.15 (m, 2H), 6.99 (dd, J = 10.4, 0.7 Hz, 1H), 6.77 (dt, J = 8.2, 0.8 Hz, 1H), 6.63 (d, J = 8.3 Hz, 1H), 5.79 (d, J = 10.3 Hz, 1H), 3.03 (s, 3H), 2.85 (s, 3H), 1.36 (s, 3H), 1.21 (s, 3H).

[0407] 52 1 H NMR (500 MHz, Methanol-d4, d 4) δ 7.89 7.81 (m, 2H), 7.79 (dd, J = 8.4, 2.0 Hz, 1H), 7.70 7.60 (m, 3H), 7.35 7.24 (m, 2H), 7.11 (d, J = 10.3 Hz, 1H), 6.94 (d, J = 8.3 Hz, 1H), 6.82 (d, J = 8.4 Hz, 1H), 5.98 (d, J = 10.3 Hz, 1H), 3.61 3.42 (m, 2H), 3.12 (s, 3H), 2.93 2.78 (m, 2H), 2.23 2.03 (m, 2H), 1.38 (s, 3H), 1.25 (s, 3H).

[0408] 531 H NMR (300 MHz, dichloromethane-) d 2) δ 7.79 7.63 (m, 7H), 7.62 7.54 (m, 1H), 7.53 7.45 (m, 2H), 6.99 (d, J = 10.4 Hz, 1H), 6.85 (d, J = 8.5 Hz, 1H), 6.62 6.54 (m, 1H), 5.87 (d, J = 10.3 Hz, 1H), 2.85 (s, 3H), 1.33 (s, 3H), 1.22 (s, 3H).

[0409] 55 1 H NMR (300 MHz, dichloromethane-) d 2) δ 8.05 7.92 (m, 2H), 7.68 7.60 (m, 2H), 7.58 7.43 (m, 3H), 7.14 (d, J = 8.8 Hz, 1H), 7.03 (d, J = 8.6 Hz, 1H), 6.96 6.89 (m, 2H), 6.80 6.74 (m, 1H), 6.70 (d, J = 8.6 Hz, 1H), 5.69 (d, J = 10.3 Hz, 1H), 3.15 (s, 3H), 1.46 (s, 3H), 1.22 (s, 3H).

[0410] 56 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.59 (dd, J = 8.3, 1.9 Hz, 1H), 7.517.15 (m, 8H), 7.06 6.91 (m, 2H), 6.29 (d, J = 8.2 Hz, 1H), 5.68 (d, J = 10.3 Hz, 1H), 2.99 (s, 3H), 2.64 (s, 3H), 1.08 (s, 6H).

[0411] 57 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.82 7.41 (m, 8H), 7.28 (dd, J= 7.4, 1.8 Hz, 1H), 7.01 (d, J = 10.3 Hz, 1H), 6.92 (dd, J = 7.9, 7.3 Hz, 1H), 6.56 (d, J =8.6 Hz, 1H), 5.85 (d, J = 10.3 Hz, 1H), 2.83 (s, 3H), 2.09 (s, 3H), 1.36 (s, 3H), 1.25 (s, 3H).

[0412] 58 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.78 7.64 (m, 5H), 7.61 7.53 (m, 1H), 7.52 7.44 (m, 2H), 7.31 (dd, J = 7.8, 1.2 Hz, 1H), 7.20 (t, J = 7.9 Hz, 1H), 6.89 (ddd, J = 8.1, 1.2, 0.8 Hz, 1H), 6.53 (dd, J = 7.9, 0.8 Hz, 1H), 5.82 (d, J = 10.7 Hz, 1H), 2.83 (s, 3H), 2.59 (s, 3H), 1.32 (s, 3H), 1.21 (s, 3H).

[0413] 59 1 H NMR (300 MHz, dichloromethane-) d 2) δ 7.83 7.66 (m, 3H), 7.63 7.49 (m, 2H), 7.50 7.36 (m, 2H), 7.21 (s, 1H), 6.91 (d, J = 10.3 Hz, 1H), 6.63 (d, J = 8.3 Hz, 1H), 6.38 (s, 1H), 5.62 (d, J = 10.2 Hz, 1H), 3.59 (s, 3H), 3.03 (s, 3H), 2.86 (s, 3H), 1.39 (s, 3H), 1.21 (s, 3H).

[0414] 60 1 H NMR (300 MHz, dichloromethane-) d2) δ 7.79 7.65 (m, 6H), 7.62 7.53 (m, 1H), 7.49 (m, 2H), 7.22 7.14 (m, 1H), 6.79 6.66 (m, 1H), 6.63 6.50 (m, 1H), 5.74 (d, J =10.2 Hz, 1H), 2.84 (s, 3H), 2.23 (s, 6H), 1.29 (s, 3H), 1.24 (s, 6H), 1.17 (s, 3H).

[0415] 61 1 H NMR (300 MHz, dichloromethane- d 2) δ 8.02 (dd, J = 2.2, 0.7 Hz, 1H), 7.92 (d, J = 2.2 Hz, 1H), 7.79 7.68 (m, 4H), 7.62 7.53 (m, 1H), 7.53 7.45 (m, 2H), 7.05 (d, J =10.5 Hz, 1H), 6.61 6.54 (m, 1H), 5.91 (d, J = 10.4 Hz, 1H), 2.79 (s, 3H), 2.55 (s, 3H), 1.36 (s, 3H), 1.25 (s, 3H).

[0416] 62 1 H NMR (300 MHz, dichloromethane- d 2) δ 8.16 (d, J = 1.8 Hz, 1H), 8.00 7.92 (m, 1H), 7.85 7.78 (m, 1H), 7.75 7.67 (m, 2H), 7.59 7.38 (m, 4H), 7.34 7.18 (m, 2H), 7.136.98 (m, 3H), 5.93 (d, J = 10.3 Hz, 1H), 2.90 (s, 3H), 1.64 (s, 3H), 1.34 (s, 3H).

[0417] 63 1 H NMR (500 MHz, dichloromethane-) d 2) δ 7.77 7.65 (m, 4H), 7.59 7.54 (m, 1H), 7.53 7.46 (m, 2H), 7.33 7.25 (m, 1H), 7.03 (d, J= 1.4 Hz, 1H), 6.97 (s, 1H), 6.54 (d, J = 8.2 Hz, 1H), 5.79 (d, J = 10.5 Hz, 1H), 3.92 (s, 3H), 2.83 (s, 3H), 2.47 (s, 3H), 1.34 (s, 3H), 1.21 (s, 3H).

[0418] 64 1 H NMR (300 MHz, methanol-) d 4) δ 7.83 (s, 1H), 7.77 7.68 (m, 2H), 7.67 7.58 (m, 1H), 7.50 (tt, J = 7.5, 0.8 Hz, 2H), 7.36 7.21 (m, 2H), 7.19 7.06 (m, 2H), 5.91 (d, J = 10.3 Hz, 1H), 3.20 (s, 3H), 1.51 (s, 3H), 1.28 (s, 3H).

[0419] 65 1 H NMR (300 MHz, methanol-) d 4) δ 7.49 (dd, J = 7.8, 1.7 Hz, 1H), 7.43 (d, J =8.6 Hz, 1H), 7.29 (d, J = 1.4 Hz, 1H), 7.22 (d, J = 7.9 Hz, 1H), 7.13 (d, J = 8.6 Hz, 1H), 7.10 7.04 (m, 1H), 5.91 (d, J = 10.3 Hz, 1H), 3.15 (s, 3H), 2.95 (q, J = 5.9, 4.7Hz, 2H), 2.27 2.16 (m, 2H), 1.98 1.87 (m, 2H), 1.61 (s, 3H), 1.35 (s, 3H).

[0420] 66 1 H NMR (300 MHz, methanol-) d 4) δ 7.77 7.68 (m, 2H), 7.65 7.57 (m, 1H), 7.547.46 (m, 2H), 7.42 (d, J= 8.6 Hz, 1H), 7.32 7.21 (m, 2H), 7.18 7.02 (m, 3H), 5.93 (d, J = 10.3 Hz, 1H), 3.18 (s, 3H), 1.64 (s, 3H), 1.36 (s, 3H).

[0421] 67 1 H NMR (500 MHz, Methanol-d4) δ 8.88 (d, d 4) δ 8.16 (s, 1H), 4.57 (s, 3H), 2.51 (s, 3H), 1.76 (s, 6H). J = 8.6 Hz, 1H), 7.71 (d, J = 8.6 Hz, 1H), 4.32 (s, 3H), 1.89 (s, 6H).

[0422] 68 1 H NMR (300 MHz, Methanol-d4) δ 8.88 (d, d 4) δ 8.16 (s, 1H), 4.57 (s, 3H), 2.51 (s, 3H), 1.76 (s, 6H).

[0423] 69 1 H NMR (500 MHz, Methanol-d4) δ 8.88 (d, d 4) δ 8.88 (d, J = 1.4 Hz, 1H), 8.60 (d, J = 1.4 Hz, 1H), 4.12 (s, 3H), 1.82 (s, 6H).

[0424] 70 1 H NMR (300 MHz, Methanol-d4) δ 8.88 (d, d 4) δ 8.19 (dd, J = 1.7, 0.5 Hz, 1H), 8.02 (dd, J = 8.4, 1.6 Hz, 1H), 7.65 7.60 (m, 1H), 4.02 (s, 3H), 1.60 (s, 6H).

[0425] 71 1 H NMR (300 MHz, Methanol-d4) δ 8.88 (d, d 4) δ 8.16 (t, J = 1.1 Hz, 1H), 8.00 (d, J = 1.1 Hz, 2H), 7.85 7.74 (m, 2H), 7.74 7.66 (m, 1H), 7.62 7.51 (m, 2H), 4.13 (s, 3H), 1.67 (s, 6H).

[0426] 72 1 H NMR (300 MHz, Methanol-d4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). d 4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H).

[0427] 73 1 H NMR (300 MHz, Methanol-d4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). d 4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). J = 8.3 Hz, 1H), 8.17 (s, 1H), 4.19 (s, 3H), 3.33 (s, 3H), 1.75 (s, 6H).

[0428] 74 1 H NMR (300 MHz, Methanol-d4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). J = 8.3 Hz, 1H), 8.17 (s, 1H), 4.19 (s, 3H), 3.33 (s, 3H), 1.75 (s, 6H). J = 8.3 Hz, 1H), 8.17 (s, 1H), 4.19 (s, 3H), 3.33 (s, 3H), 1.75 (s, 6H). J = 8.3 Hz, 1H), 8.17 (s, 1H), 4.19 (s, 3H), 3.33 (s, 3H), 1.75 (s, 6H). J = 8.3 Hz, 1H), 8.17 (s, 1H), 4.19 (s, 3H), 3.33 (s, 3H), 1.75 (s, 6H).

[0429] 75 1 H NMR (300 MHz, Methanol-d4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). d 4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H).

[0430] 76 1 H NMR (300 MHz, Methanol-d4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). d 4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H).

[0431] 77 1 H NMR (300 MHz, Methanol-d4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H). d 4) δ 8.20 8.05 (m, 1H), 8.03 7.84 (m, 1H), 7.847.60 (m, 2H), 7.60 7.39 (m, 2H), 7.36 7.00 (m, 2H), 4.85 4.21 (m, 2H), 3.12 2.75 (m, 2H), 2.45 1.92 (m, 2H), 1.71 1.45 (m, 6H).J = 8.8, 0.9 Hz, 1H), 8.45 8.32 (m, 1H), 8.16 (d, J = 9.0 Hz, 1H), 7.98 (dd, J = 8.8, 1.7 Hz, 1H), 4.19 (s, 3H), 1.85 (s, 6H).

[0432] 79 1 H NMR (500 MHz, Methanol-d4, d 2) δ 7.82 7.78 (m, 2H), 7.77 7.72 (m, 2H), 7.66 (dd, J = 8.1, 1.7 Hz, 1H), 7.57 (d, J = 1.7 Hz, 1H), 6.97 (dd, J = 10.4, 0.7 Hz, 1H), 6.78 6.74 (m, 1H), 6.74 6.69 (m, 2H), 6.55 (d, J = 8.1 Hz, 1H), 5.78 (d, J = 10.3Hz, 1H), 3.85 (s, 3H), 3.06 (s, 6H), 2.82 (s, 3H), 1.32 (s, 3H), 1.20 (s, 3H).

[0433] 80 1 H NMR (500 MHz, Methanol-d4, d 2) δ 8.27 (dd, J = 8.0, 1.8 Hz, 1H), 8.22 (d, J = 8.4 Hz, 1H), 7.91 (d, J = 2.1 Hz, 1H), 7.83 (d, J = 2.1 Hz, 1H), 7.76 (dd, J =8.2, 1.4 Hz, 2H), 7.70 (ddd, J = 8.7, 7.1, 1.8 Hz, 1H), 7.66 7.61 (m, 1H), 7.53 (t, J =7.7 Hz, 2H), 7.46 (dd, J = 8.4, 1.0 Hz, 1H), 7.36 (ddd, J = 8.1, 7.1, 1.1 Hz, 1H), 7.07(d, J= 10.4 Hz, 1H), 6.69 (d, J = 8.4 Hz, 1H), 5.94 (d, J = 10.4 Hz, 1H), 2.87 (s, 3H), 1.69 (s, 3H), 1.42 (s, 3H).

[0434] 81 1 1H NMR (500 MHz, methanol- d 4) δ 7.62 7.59 (m, 1H), 7.45 7.42 (m, 3H), 7.40(d, J = 7.6 Hz, 1H), 7.36 7.34 (m, 2H), 7.33 7.27 (m, 2H), 7.11 (d, J = 10.3 Hz, 1H), 7.05 (t, J = 7.6 Hz, 1H), 6.58 (d, J = 8.4 Hz, 1H), 5.90 (d, J = 10.3 Hz, 1H), 3.58 3.39 (m, 2H), 3.09 (s, 3H), 2.86 2.76 (m, 2H), 2.09 1.97 (m, 2H), 1.34 (s, 3H), 1.13(s, 3H).

[0435] 82 1 1H NMR (500 MHz, methanol- d 4) δ 7.77 (ddd, J = 11.0, 8.4, 1.7 Hz, 3H), 7.68 7.59 (m, 2H), 7.58 7.50 (m, 2H), 7.35 (d, J = 7.8 Hz, 1H), 7.30 (dd, J = 7.8, 1.6 Hz, 1H), 7.15 (d, J = 10.3 Hz, 1H), 7.07 (d, J = 1.4 Hz, 1H), 6.93 (d, J = 8.4 Hz, 1H), 6.06 (d, J = 10.3 Hz, 1H), 3.59 3.43 (m, 2H), 3.12 (s, 3H), 2.91 2.80 (m, 2H), 2.23 2.06 (m, 2H), 1.39 (s, 3H), 1.26 (s, 3H).

[0436] 83 1 H NMR (500 MHz, methanol-) d 4) δ 7.43 7.33 (m, 5H), 7.30 (d, J = 8.6 Hz, 1H), 7.24 (dd, J = 8.7, 6.9 Hz, 2H), 7.05 (d, J = 10.4 Hz, 1H), 7.02 6.95 (m, 2H), 5.72 (d, J = 10.4 Hz, 1H), 2.97 (s, 3H), 1.44 (s, 3H), 1.24 (s, 3H).

[0437] 84 1 H NMR (300 MHz, dichloromethane-) d 2) δ 8.45 8.31 (m, 1H), 7.90 7.77 (m, 1H), 7.77 7.68 (m, 2H), 7.60 7.49 (m, 1H), 7.49 7.28 (m, 7H), 7.23 (t, J = 8.3 Hz, 1H), 7.14 6.98 (m, 2H), 5.96 (d, J = 10.3 Hz, 1H), 3.37 (s, 3H), 1.39 (s, 3H), 1.19 (s, 3H).

[0438] 87 1 H NMR (500 MHz, dichloromethane-) d 2) δ 7.72 (dd, J = 8.4, 1.9 Hz, 1H), 7.61(dd, J = 8.3, 1.9 Hz, 1H), 7.59 (d, J = 1.9 Hz, 1H), 7.50 7.47 (m, 2H), 7.45 (ddd, J =7.5, 1.6, 0.8 Hz, 1H), 7.42 7.37 (m, 1H), 7.35 (d, J = 1.9 Hz, 1H), 7.28 7.21 (m, 3H), 6.96 (t, J = 7.6 Hz, 1H), 6.64 (d, J = 8.4 Hz, 1H), 6.36 (d, J= 8.3 Hz, 1H), 4.42 (d, J = 10.2 Hz, 1H), 3.13 (s, 3H), 3.02 (s, 3H), 2.99 (s, 3H), 2.54 (s, 3H), 2.37 (dd, J =14.2, 4.9 Hz, 1H), 2.20 2.10 (m, 1H), 1.67 (s, 3H), 1.65 (s, 3H), 1.31 (s, 3H), 1.25 (s, 3H), 1.22 1.18 (m, 1H).

[0439] 91 1H NMR (500 MHz, dichloromethane-d2) δ 7.72 7.68 (m, 2H), 7.58 7.54 (m, 2H), 7.53 7.47 (m, 4H), 7.41 (d, J = 1.8 Hz, 1H), 7.40 7.37 (m, 1H), 7.31 (dd, J = 7.6, 1.7 Hz, 1H), 7.27 (dd, J = 7.5, 1.7 Hz, 1H), 7.26 7.22 (m, 2H), 6.97 (dd, J = 8.9, 1.4 Hz, 2H), 6.25 (d, J = 8.2 Hz, 1H), 5.70 (d, J = 10.3 Hz, 1H), 2.66 (s, 3H), 1.09 (s, 3H), 1.08 (s, 3H).

[0440] B. Preparations

[0441] In some cases, it may be advantageous to freeze-dry the two-color photoinitiator before formulation.

[0442] Example 1 Formulation 1

[0443] Initiator 66 (1 mg) was dissolved in a mixture of methyldiethanolamine (1 g), PEG-diacrylate (MW575) (1 g), and gelatin methacrylate (8 g). The mixture was shaken at 50°C until the components were fully mixed, and then allowed to cool to room temperature before printing.

[0444] Example 2 Formulation

[0445] Initiator 43 (2 mg) was dissolved in methyldiethanolamine (0.4 g) and dicarbamate dimethacrylate (isomeric mixture, CAS 72869-86-4) (10 g). The mixture was stirred until homogenized and ready for printing.

[0446] Example 3 Formulation

[0447] Initiator 55 (2 mg) was dissolved in methyldiethanolamine (0.4 g) and diaminocarbate dimethyl acrylate (mixture of isomers, CAS 72869-86-4) (10 g). The mixture was stirred until homogenized and can be used directly for printing.

[0448] Example Formulation 4

[0449] Initiator 56 (10 mg) was dissolved in acryloylmorpholine (0.4 g), methyldiethanolamine (0.4 g) and diaminocarbate dimethyl acrylate (mixture of isomers, CAS 72869-86-4) (10 g). The mixture was stirred until homogenized and can be used directly for printing.

[0450] C. Printing

[0451] The above formulations were used for volumetric printing.

[0452] The setup for volumetric printing was as follows: a cuvette with four transparent windows was illuminated with a light sheet of wavelength 1 in one direction while an image was projected from different angles onto the light sheet with wavelength 2. When the light sheet moved through the cuvette, the image was changed to create an animation. Printing resulted in solidification only in the volumes where the light of the two wavelengths intersected. Residual un-solidified resin was removed to obtain the shaped body which was further washed with solvent and post-processed.

[0453] It has been found that Formulation 1, Formulation 2, Formulation 3 and Formulation 4 are successfully used for volumetric printing with the use of two different wavelengths of light. Exemplarily, the following wavelengths can be used: Formulation 1, 3, 4: 375 nm and 500-700 nm Formulation 2: 405 nm and 500-700 nm.

[0454] Post-processing of shaped bodies manufactured from Formulation 4 is exemplarily described: Post-processing Example 1 : After washing with ethanol, the three-dimensional object was illuminated with light of wavelength 420 nm (Thorlabs M420L3, 750 mW) for 30 minutes, whereby the absorption of the object in the visible wavelength range was significantly reduced.

[0455] Post-processing Example 2: After washing with ethanol, the three-dimensional object was placed in a heatable chamber, where the three-dimensional object was tempered at 120 °C for 30 minutes, whereby the absorption in the visible wavelength range was significantly reduced.

[0456] Dual-color photoinitiating properties of spiropyran moieties

[0457] It has been found in the examples that when R4 For H and R 11 When the spiropyran is benzoyl, the resulting spiropyran is not suitable as a two-color photoinitiator because its switching efficiency is very low, exhibiting low quantum yield and very slow thermal reverse reaction, which makes it impossible to achieve printing with z-axis resolution.

[0458] When R 4 and R 11 When the benzoyl group is used, the resulting spiropyran is suitable as a two-color photoinitiator, possessing a sufficiently fast thermal reverse reaction, sufficiently high switching efficiency, and sufficiently high reactivity, thus allowing volumetric printing in two-color volumetric printing processes.

[0459] When R 4 and R 13 When (structure 91) is benzoyl (obtainable using the methods described herein), similar switching efficiency is observed, but surprisingly, the thermal reverse reaction rate and reactivity are also enhanced.

[0460] Furthermore, it has been found that when R 4 Surprisingly, when the moiety is benzoyl, the resulting moiety results in an extinction coefficient at 405 nm that is high enough to allow 405 nm to be used as the first wavelength required to switch to the intermediate state.

[0461] In contrast, when R 11 It is benzoyl and R 4 When R is H, the extinction coefficient at 405 nm is not high enough, so the first wavelength needs to be shifted to 375 nm. Using 405 nm as the first wavelength for irradiation may be more advantageous than 375 nm because the laser diode can achieve higher power at a lower cost. Furthermore, 405 nm is less damaging to cells, which may be important when printing in the presence of cells. 11 When the group is acyl, the extinction coefficient at 405 nm is insufficient for printing, but it is comparable to R. 11 Compared to the corresponding structures of benzoyl, ester, cyano, or CF3, the intermediate state exhibits surprisingly high reactivity under visible light and with co-initiators. 4 Benzoyl group and R 11 The performance of the bicolor photoinitiators produced by the combination of acyl groups (43) is surprisingly good, outperforming bicolor photoinitiators with only one carbonyl group or two identical carbonyl substituents.

[0462] In other embodiments, it has been found that when R 4 For SO2Me and R 11 When R is 4-F-benzoyl (51), the switching efficiency is surprisingly high, the quantum yield is close to 1, and the thermal reverse reaction is accelerated to a thermal half-life of a few seconds, thus achieving good printing performance.4 SO2Me and R 13 benzoyl (instead of R 11 ) (56) the switching efficiency is equally high and the quantum yield close to 1, but surprisingly the thermal back reaction rate and the initiation efficiency are even further improved, thus enabling printing performance superior to 51 in terms of resolution, printing speed and green body hardness.

[0463] From a large number of examples design rules for specific properties can be derived, for example: • having a stronger acceptor at R 4 can accelerate the back reaction rate and the switching efficiency.

[0464] • a benzoyl substituent on the pyran ring can cause a red shift of the spiropyran absorption spectrum, with the effect strength from strong to weak in the order: R 4 > R 12 > R 11 > R 13 > R 10 .

[0465] • a benzoyl substituent on the pyran ring can cause a suitable thermal back reaction rate, with the order from high to low: R 10 > R 12 > R 13 > R 11 .

[0466] The features disclosed in the specification and in the claims can be relevant to the implementation of various designs, alone or in any combination.

[0467] General findings on the printing method

[0468] Printing with photoinitiators 43, 48, 51 and 56 at different concentrations of the two-color photoinitiator and at varying first wavelength has been investigated. The initiators each carry an aroyl substituent in a different position, which causes a shift of the initial state absorption spectrum. Volume printing was performed as follows, where a cuvette with four transparent windows was illuminated with a light sheet of wavelength 1 in one direction, while an image was projected from the perpendicular direction onto the light sheet with wavelength 2. The image was changed as the cuvette moved through the light sheet to create an animation. Printing can result in solidification only in the volume where the two wavelengths of light intersect. Residual uncured resin was removed to obtain a shaped body, which was further washed with solvent and post-processed.

[0469] Table 1: Extinction coefficients (in L mol -1 cm -1) and the thermal half-life at room temperature. The measurements were performed in a typical resin used for volume printing: urethane dimethacrylate containing 3.5% N-methyldiethanolamine and 4.5% acryloylmorpholine.

[0470]

[0471] Although photochemical reactions should ideally be performed at the wavelength where the substance has its maximum absorption, surprisingly, tests did not lead to successful printing when a light sheet was generated near the wavelength of maximum absorption of the initial state. Instead, only solidification on the cuvette walls was observed. This can be explained by Beer's law: because near the wavelength of maximum absorption, photons are absorbed close to the cuvette walls, thus also causing the polymerization reaction to occur only close to the cuvette walls, while only a small fraction of the light reaches the middle of the cuvette.

[0472] To solve this problem, the concentration has been lowered such that the absorption at the wavelength of maximum absorption / first wavelength has been reduced to 1 or less.

[0473] Surprisingly, the problem of the penetration depth has been solved, but no solidification was observed at all. It is assumed that the concentration of the two-color photoinitiator in these experiments was too low to form a sufficient number of radicals.

[0474] Surprisingly, when a first wavelength was chosen in the red tail of the absorption spectrum, where the extinction coefficient of the initial state is lower, printing in the middle of the cuvette has been successful, without solidification on the walls. This is contrary to intuition, because one would expect that the fewer photons the initiator absorbs, the fewer radicals are formed, but surprisingly, more radicals are formed in the middle of the cuvette. However, when the first wavelength is shifted further to a region where the extinction coefficient of the initial state is even lower, no solidification is observed anymore, or a large increase in intensity is required, which again only leads to solidification on the cuvette walls. When the concentration is increased to the point where solidification can be observed, the solidification again mainly occurs on the walls. This can be explained by the presence of small amounts of impurities, which have a relatively high extinction coefficient compared to the initial state, or a relatively higher intensity of the first wavelength is required to cause the switching. By comparing the printing of different concentrations and first wavelengths, it has been found that the following conditions improve the printing results compared to the prior art. The concentration of the initiator can be increased sufficiently to achieve the two-color effect when the first wavelength is adjusted accordingly based on the extinction coefficient. Surprisingly, these conditions are not related to the structure of the initiator itself, but rather seem to be related to a surprising combination of the limitations imposed by both Beer's law and the two-color effect: 1) The extinction coefficient of the two-color photoinitiator at the first wavelength should be in the range of 5000 to 0 L mol -1 cm -1 1) The extinction coefficient of the two-color photoinitiator at the first wavelength should be in the range of 5000 to 0 L mol-1 cm -1 , more preferably 1000 to 20 L mol -1 cm -1 , even more preferably 500 to 50 L mol -1 cm -1 , most preferably 300 to 100 L mol -1 cm -1 .

[0475] 2) The absorbance of the resin at the first wavelength should be in the range of 1 to 0.05, preferably 0.9 to 0.1, more preferably 0.8 to 0.15, at a distance of 1 cm, using a non-absorbing solvent such as acetonitrile as a reference.

[0476] The ideal first wavelength for the initiators given in Table 1 are: 43: 405 nm, 48: 395 nm, 51 : 385 nm, 56: 375 nm.

[0477] Surprisingly, the preferred properties of the initiator and resin are independent of the object to be printed, but depend on the size of the container and the path length the light of the first wavelength needs to travel. Since the Beer's law involves the path length of the light, the importance of the issue of the penetration depth is lower for smaller build spaces of e.g. 1 x 1 x 1 mm 3 ; while for build spaces of > 5 x 5 x 5 mm 3 , preferably > 10 x 10 x 10 mm 3 , the above criteria ensure a significant boost in printing performance. As a non-limiting example, when a formulation containing 51 is subjected to a two-color polymerization, no curing is observed using 405 nm as the first wavelength, while 395 nm and 375 nm result in an acceptable quality green state, and 385 nm enables the highest degree of polymerization. Furthermore, by adjusting the extinction coefficient, it is possible to increase the build space while still maintaining a green state that is sufficiently polymerized.

Claims

1. A method for manufacturing spiropyran represented by the following formula (1): (Equation (1)); The method includes the following steps: A precursor is provided, wherein the precursor is a spiropyran represented by the following formula (2): (Equation (2)); Provide reactants, wherein the reactants are Indolonium salts represented by the following formula (3): (Equation (3)) Or the corresponding 2-methyleneindoline compound; or Salicylaldehyde is represented by the following formula (4): (Equation (4)); or Spiropyrans represented by the following formula 5: (Equation (5)); Optionally, the precursor may be pre-activated; A reaction mixture comprising the precursor or optionally a pre-activated precursor, and the reactants is provided to obtain the spiropyran of formula (1); The spiropyran, the precursor, and the reactant are different from each other; If the reactant is an indoleon salt of formula (3), then the obtained spiropyran of formula (1) is represented by the following formula (1A): (Equation (1A)), In equation (1A), R" 1 To R" 8 Independently with R" of equation (3) 1 To R" 8 The same, and R' of equation (1A) 9 To R' 13 Independently with R' of equation (2) 9 To R' 13 same; If the reactant is salicylaldehyde of formula (4), then the obtained spiropyran of formula (1) is represented by the following formula (1B): (Equation (1B)), In equation (1B), R' 1 To R' 8 Independently with R' of equation (2) 1 To R' 8 The same, and R" of equation (1B) 9 To R" 13 Independently with R" of equation (4) 9 To R" 13 same; If the reactant is spiropyran of formula (5), The obtained spiropyran of equation (1) is represented by equation (1A), where R" in equation (1A) 1 To R" 8 Independently with R" of equation (5) 1 To R" 8 The same, and R' of equation (1A) 9 To R' 13 Independently with R' of equation (2) 9 To R' 13 Same, or The obtained spiropyran of formula (1) is represented by formula (1B), where R' of formula (1B) 1 To R' 8 Independently with R' of equation (2) 1 To R' 8 The same, and R" of equation (1B) 9 To R" 13 Independently with R" of equation (5) 9 To R" 13 same; Where X is selected from S, C, or N; if X is S, then R is correspondingly selected from S, C, or N. 6 R 7 、R' 6 、R' 7 、R" 6 、R" 7 It may not exist; if X is N, then R is correspondingly... 7 、R' 7 、R" 7 It may not exist; Wherein Y is selected from O, S, or N; when Y is N, the substituent contains a substance similar to R. 13 The atoms necessary to form a cyclic structure, wherein the cyclic structure is selected from benzimidazole, indoline, indole, dihydroquinoline, and tetrahydroquinoline; Where Z is selected from N or C; If it exists, A is selected from O, S, or Se; If it exists, B is selected from H or D; If it exists, Hal - It is a halogen anion or anionic compound; If R exists, 1 To R 13 、R' 1 To R' 13 and R" 1 To R" 13 Independently selected from the following groups: H; D; halogen; NO2; CN; OH; SH; CF3; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 aryloxy group; NH2; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; substituted or unsubstituted C1-C 20 Alkylamides; substituted or unsubstituted C6-C 48 Arylamide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R's can form a ring structure; substituted or unsubstituted carboxylic acids and their salts; substituted or unsubstituted sulfonic acids and their salts; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; formyl group; ethers, thioethers; carbonates; carbonates; sulfates / esters; boric acid; borate esters; phosphonic acid; phosphonates; phosphine; phosphates / esters; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinates; sulfonates; thiolates, sulfoxides; sulfones; alkyl sulfones; acyl hydrazides; thioaldehydes; ketones; thioketones; oximes; hydrazides Nitrosyl; Azo; Diazo; Diazo salt; Isocyanate; Cyanate; Isocyanate; Thiocyanate; Isothiocyanate; Hydroperoxide; Peroxide; Acetal; Ketal; Orthoester; Orthocarbonate; Ammonium; Imine; Imide; Azide; Nitrate / Ester; Isonitrile; Nitrite group; Substituted or unsubstituted urethane; Substituted or unsubstituted ether; Substituted or unsubstituted polyether urethane; Substituted or unsubstituted aryl azo; Substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 alkenyl; Where R 1 To R 13 If one or more of the following substances contain one or more substituents, then the substituents are independently selected from the group consisting of: D; halogens; NO2; CN, C2-C. 49 Alkyl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy group; substituted or unsubstituted C2-C 49 Aryl acyl; (meth)acrylate; toluenesulfonyl; sulfonic acid or its salt; carboxylic acid or its salt; boric acid or its salt; phosphonic acid or its salt; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, the two R's can form a ring structure; NH2; and OH; If R exists, 2 To R 5 、R' 2 To R' 5 、R" 2 To R" 5 R 10 To R 13 、R' 10 To R' 13 and R" 10 To R" 13 Two adjacent groups can independently connect with each other to form a fused ring structure; and If R" exists, A To R" B Selected independently from H and D.

2. The method according to claim 1, In equation (1), R 2 To R 5 and R 10 To R 13 At least one of them is a substituent selected from one of the following structures: , , , , , , and ; Where R 14 To R 27 Independently selected from the following groups: H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 aryloxy group; NH2; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; substituted or unsubstituted C1-C 20 Alkylamides; substituted or unsubstituted C6-C 48 Arylamide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R's can form a ring structure; substituted or unsubstituted carboxylic acids and their salts; substituted or unsubstituted sulfonic acids and their salts; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; formyl group; ether; thioether; carbonate; carbonate; sulfate / ester; boric acid; borate; phosphonic acid; phosphonate; phosphine; phosphate / ester; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinate; sulfonate; thiol ester, sulfoxide; sulfone; alkyl sulfone; acyl hydrazine; thioaldehyde; ketone; thione; oxime; hydrazine Nitrosyl; Azo; Diazo; Diazo salt; Isocyanate; Cyanate; Isocyanate; Thiocyanate; Isothiocyanate; Hydroperoxide; Peroxide; Acetal; Ketal; Orthoester; Orthocarbonate; Ammonium; Imine; Imide; Azide; Nitrate / Ester; Isonitrile; Nitrite group; Substituted or unsubstituted urethane; Substituted or unsubstituted ether; Substituted or unsubstituted polyether urethane; Substituted or unsubstituted aryl azo; Substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 alkenyl; wherein if R 14 To R 27 If one or more of the following substances contain one or more substituents, then the substituents are independently selected from the group consisting of: D; halogens; NO2; CN, C2-C. 49 Alkyl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy group; substituted or unsubstituted C2-C 49 Aryl acyl; (meth)acrylate; toluenesulfonyl; sulfonic acid or its salt; carboxylic acid or its salt; boric acid or its salt; phosphonic acid or its salt; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; NH2; and OH; and R 15 and R 16 They can connect with each other to form unsubstituted or substituted ring structures; and / or In equation (1), R 2 To R 5 and R 10 To R 13 At least one of them is a substituent selected from the group consisting of: chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; acetyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; and toluenesulfonyl; and / or In equation (1), R 2 To R 5 and R 10 To R 13 At least one of them is a substituent selected from the group consisting of: sulfonic acid or a salt thereof; carboxylic acid or a salt thereof; Boric acid or its salts; phosphonic acid or its salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; (meth)acrylates; toluenesulfonyl group; NH2 and OH; and / or In equation (1), R 1 Selected from H, D, substituted or unsubstituted C1-C6 alkyl groups, -CH2-CH2-OH, -CH2-COOH, -CH2-CH2-COOH, -CH2-CH2-CH2-nMe3 + -CH2-CH2-CH2-SO3 - phenyl and benzyl, preferably R 1 It can be methyl, -CH2-CH2-OH, phenyl or benzyl, -CH2-COOH, -CH2-CH2-COOH, or -CH2-CH2-CH2-nMe3. + and -CH2-CH2-CH2-SO3 - ; and / or R 14 To R 27 Substituents on any of them, preferably R 19 The substituents on it can contain R 5 To R 8 Or R 10 To R 13 One of them together forms the necessary atoms to form a ring structure.

3. The method according to any one of the preceding claims, wherein in formula (1), R 2 To R 5 At least one of them and another R 10 To R 13 At least one of them is a substituent selected from one of the following formulas: , , , , , , and ; Where R 14 To R 27 As defined in claim 2, and / or Where R 10 and R 12 To R 13 At least one of them is a substituent selected from one of the following structures: , , , , , , and ; Where R 14 To R 27 As defined in claim 2.

4. The method according to any one of the preceding claims, wherein in formula (2), R' 2 To R' 5 and R' 10 To R' 13 Of which at least one, R' is preferred. 10 To R' 13 At least one of them is a substituent selected from electron-withdrawing substituents, acetyl groups, benzoyl groups, CN, CF3, or one of the following structures: , , , , , , and ; Where R 14 To R 27 As defined in claim 2, or In equation (2), R' 2 To R' 5 Of which at least one, R' is preferred. 4 It is a substituent selected from electron-donating substituents, alkoxy groups, methoxy groups, or one of the following structures: , , , , , , and , Where R 14 To R 27 As defined in claim 2; and / or Where R' 10 To R' 13 At least one of them is CF3; and / or Where R' 8 It is an alkyl group, preferably methyl.

5. The method according to any one of the preceding claims, wherein the precursor is preactivated with a nucleophile, preferably an amine base, more preferably a primary or secondary amine base, before the reaction mixture is provided, to obtain a preactivated precursor.

6. The method according to any one of the preceding claims, wherein the reactant is an indoleon salt of formula (3): (Equation (3)) Or the corresponding 2-methyleneindoline compounds; Among them, X, Hal, and R" A 、R" B and R" 1 To R" 8 It is a substituent as defined in claim 1; Among them, the preferred formula (3) has R". 2 To R" 5 The number of electron-withdrawing substituents is higher than that of R' in equation (2). 10 To R' 13 The number of electron-withdrawing substituents; and / or In equation (3), R" 4 The substituent in is R' in formula (2). 4 The substituents in it are stronger electron-withdrawing groups. and / or In equation (3), R" 4 The substituents are selected from the following group: carbonyl; chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; acetyl; benzoyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2.

7. The method according to any one of the preceding claims, wherein the reaction mixture further comprises a catalytic amount of a base, preferably a secondary amine base.

8. The method according to any one of the preceding claims, wherein the indolonium salt of formula (2) is formed from a corresponding 2-methyleneindoline compound and an acid, wherein preferably the acid is an organic acid or an inorganic acid, more preferably the acid is selected from hydrochloric acid, acetic acid or formic acid.

9. The method according to any one of the preceding claims, wherein the reactant is activated by converting the indolonium salt of formula (3) into the corresponding 2-methyleneindoline compound (3A) before mixing the precursor with the reactant in the reaction mixture, and then the activated reactant is added to the reaction mixture, wherein preferably the reactant is activated with a base, more preferably with an alkylamine, hydroxide or carbonate.

10. The method according to any one of the preceding claims, wherein an excess of more than 1.1 equivalents of the indolonium salt of formula (3) or the corresponding methyleneindoline of formula (3A) is added to the reaction mixture, preferably an excess of 1.1 to 1.2 equivalents of the indolonium salt or the corresponding methyleneindoline of formula (3A) based on the precursor.

11. The method according to any one of claims 1 to 9, wherein an excess of an indoline salt of formula (3) of formula (3) based on the precursor is added to the reaction mixture to form an adduct, and the adduct is then treated with acid to form a spiropyran of formula (2).

12. The method according to claims 1 to 5, wherein the reactant is salicylaldehyde of formula (4): (Equation (4)); Among them, A, B, Z, Y and R" 9 To R" 13 It is a substituent as defined in claim 1, wherein R" is preferred. 9 It is H or D; and R" 10 To R" 13 Independently selected from the group consisting of: H; D; halogen; toluenesulfonyl; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; acetyl; benzoyl; oxime; aldehyde, NO2; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; sulfonic acid or its salt; carboxylic acid or its salt; Boric acid or its salts; phosphonic acid or its salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; NH2; OH; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 aryloxy group; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; SiR'3, -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C. 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl groups, with two R' groups, can form a ring structure. Alternatively, the reactant may be a spiropyran of formula (5): (Equation (5)); The reaction mixture may contain an additional catalyst, preferably an amine base, more preferably a primary or secondary amine base.

13. The method according to any one of the preceding claims, wherein the reaction mixture comprises a solvent, preferably an alcohol, more preferably ethanol. The obtained spiropyran has a lower solubility in the solvent than the precursor; and / or The reaction mixture further comprises a scavenging agent, which is capable of binding the obtained spiropyran, binding the obtained byproducts, or deactivating the byproducts obtained in the reaction mixture; preferably, the scavenging agent is an acid.

14. A method for manufacturing a precursor represented by the following formula (2): (Equation (2)); Where R' 1 、R' 6 To R' 9 Independently selected from the following group: H, D, substituted or unsubstituted C1-C 10 Alkyl, preferably methyl; substituted or unsubstituted C6-C 32 Aryl, preferably phenyl; substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 alkenyl and benzyl; X is C; Z is C; Y is O; R' 2 To R' 5 and R' 10 To R' 13 Independently selected from the following group: H, D, F, Cl, Br, substituted or unsubstituted C1-C 10 Alkyl, substituted or unsubstituted C6-C 32 aryl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C6-C 48 Aryloxy group, CF3, CN; wherein two adjacent groups can be linked together to form a fused ring structure, preferably a fused aromatic C6 ring; and substituents of the following formula: ， Where R 19 As defined in claim 2; Where R 2 To R 5 and R 10 To R 13 At least one of them is a substituent of the following formula: ， The method includes the following steps: Provide reactants, wherein the reactants are spiropyrans represented by the following formula (2A): (Equation (2A)); Where R' 2 To R' 5 and R' 10 To R' 13 At least one of them is a halogen atom selected from Cl, Br and I; and the remaining substituents are the same as those in the precursor of formula (2); In metal-halogen exchange reactions, preferably with organolithium reagents or Grignard reagents, the halogen atoms of the reactants react to obtain metal-spiropyran compounds. The metal-spiropyran compound is then reacted with the following venoreberamide: ， Where R 28 and R 29 Selected from the following group: substituted or unsubstituted C1-C 10 Alkyl; substituted or unsubstituted C6-C 32 Aryl; substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 Alkenyl, preferably R 28 and R 29 Each is a methyl group. To obtain the precursor of formula (2), wherein the precursor of formula (2) is preferably obtained after posttreatment with an acidic aqueous solution.

15. The method according to claim 14, wherein the reactant of formula (2A) R 2 To R 5 At least one of them is a halogen atom selected from Cl, Br and I, and the R of the reactant of formula (2A) 10 To R 13 At least one of them is a halogen atom selected from Cl, Br and I, and at least two or more of the halogen atoms react with an organolithium reagent or Grignard reagent in a metal-halogen exchange reaction, followed by a reaction with a vinorelbine to obtain the precursor of formula (2).

16. A spiropyran represented by the following formula 1: (Equation (1)); Where X is selected from S, C, or N; if X is S, then R is correspondingly selected from S, C, or N. 6 R 7 It may not exist; if X is N, then R is correspondingly... 7 It may not exist. Wherein Y is selected from O, S, or N; when Y is N, the substituent contains a substance similar to R. 13 The atoms necessary to form a cyclic structure, wherein the cyclic structure is selected from benzimidazole, indoline, indole, dihydroquinoline, and tetrahydroquinoline; Where Z is selected from N or CR 9 ; Where R 1 To R 13 Independently selected from the following groups: H; D; halogen; NO2; CN; OH; SH; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 aryloxy group; NH2; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; substituted or unsubstituted C1-C 20 Alkylamides; substituted or unsubstituted C6-C 48 Arylamide; NR'2; SiR'3; -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R's can form a ring structure; substituted or unsubstituted carboxylic acids and their salts; substituted or unsubstituted sulfonic acids and their salts; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; formyl group; ether; thioether; carbonate; carbonate; sulfate / ester; boric acid; borate; phosphonic acid; phosphonate; phosphine; phosphate / ester; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinate; sulfonate; thiolate; thiol ester; sulfone; alkyl sulfone; acyl hydrazine; thioaldehyde; ketone; thione; oxime; hydrazine; nitroso; azo; diazo; Diazonium salts; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; hydroperoxides; peroxides; acetals; ketals; orthoesters; orthocarbonates; ammonium; imines; imides; sulfonium salts; iodomonium salts; diazonium groups; azides; nitrates / esters; isonitriles; nitrite groups; substituted or unsubstituted thiocarbamates; substituted or unsubstituted carbamates; substituted or unsubstituted ethers; substituted or unsubstituted polyether carbamates; substituted or unsubstituted aryl azo groups; substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 Alkenyl; wherein two adjacent groups can be connected to each other to form a fused ring structure, preferably a fused aromatic C6 ring; Where R 1 To R 13 If one or more of the following substances contain one or more substituents, then the substituents are independently selected from the group consisting of: D; halogens; NO2; CN, C2-C. 49 Alkyl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy group; substituted or unsubstituted C2-C 49 Aryl acyl; (meth)acrylate; toluenesulfonyl; sulfonic acid or its salt; carboxylic acid or its salt; boric acid or its salt; phosphonic acid or its salt; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; NH2; and OH; wherein, if present, R 10 To R 13 and R 2 To R 5 Two adjacent groups can independently connect to each other to form a fused ring structure; and Where R 2 To R 5 and R 10 To R 13 At least one substituent is selected from the group consisting of: carbonyl; chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl; acetyl; benzoyl; oxime; aldehyde, NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; Or choose one of the following formulas: , , , , , , and , Where R 14 To R 27 Independently selected from the following group: H; D; halogen; NO2; CN; OH; SH; CF3; benzoyl; substituted or unsubstituted C1-C 20 Alkyl; substituted or unsubstituted C3-C 20 Cycloalkyl; substituted or unsubstituted C6-C 48 Aryl; substituted or unsubstituted C2-C 42 heteroaryl; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy groups and NH2; substituted or unsubstituted C1-C 20 Alkyl esters; substituted or unsubstituted C6-C 48 Aryl esters; substituted or unsubstituted C1-C 20 Alkylamides; substituted or unsubstituted C6-C 48 Arylamides; NR'2, SiR'3, -O-SiR'3, wherein R' is independently selected from substituted or unsubstituted C1-C. 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R's can form a ring structure; substituted or unsubstituted carboxylic acids and their salts; substituted or unsubstituted sulfonic acids and their salts; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; formyl group; ethers, thioethers; carbonates; carbonates; sulfates / esters; boric acid; borate esters; phosphonic acid; phosphonates; phosphine; phosphates / esters; peroxycarbonic acid; thiocarbonic acid; sulfinic acid; sulfinates; sulfonates; thiolates, sulfoxides; sulfones; alkyl sulfones; acyl hydrazides; thioaldehydes; ketones; thioketones; oximes; hydrazides Nitrosyl; Azo; Diazo; Diazo salt; Isocyanate; Cyanate; Isocyanate; Thiocyanate; Isothiocyanate; Hydroperoxide; Peroxide; Acetal; Ketal; Orthoester; Orthocarbonate; Ammonium; Imine; Imide; Azide; Nitrate / Ester; Isonitrile; Nitrite group; Substituted or unsubstituted urethane; Substituted or unsubstituted ether; Substituted or unsubstituted polyether urethane; Substituted or unsubstituted aryl azo; Substituted or unsubstituted C2-C 20 Alkyne groups and substituted or unsubstituted C2-C 20 alkenyl; Where R 14 To R 27 If one or more of the following substances contain one or more substituents, then the substituents are independently selected from the group consisting of: D; halogens; NO2; CN, C2-C. 49 Alkyl acyl; substituted or unsubstituted C1-C 20 Alkoxy; substituted or unsubstituted C6-C 48 Aryloxy group; substituted or unsubstituted C2-C 49 Aryl acyl; (meth)acrylate; toluenesulfonyl; sulfonic acid or its salt, carboxylic acid or its salt, boric acid or its salt, phosphonic acid or its salt, NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; NH2; and OH; and R 15 and R 16 They can connect with each other to form unsubstituted or substituted ring structures. and Where R 2 To R 5 and R 10 To R 13 At least one other substituent is selected from the group consisting of: chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl group; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; and / or Where R 2 To R 5 and R 10 To R 13 At least one other substituent is selected from the group consisting of: sulfonic acids or their salts; carboxylic acids or their salts; boric acids or their salts; phosphonic acids or their salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl group, two R' can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; (meth)acrylates; toluenesulfonyl group; NH2; and OH; and / or R 14 To R 27 Substituents on any of them, preferably R 19 The substituents on it can contain R 5 To R 8 Or R 10 To R 13 One of them together forms the necessary atoms to form a ring structure.

17. The spiropyran according to claim 16, wherein R 2 To R 5 At least one of the following is selected from one of the following formulas: , , , , , , and , Where R 14 To R 27 As defined in claim 16, and Where R 10 To R 13 At least one of them is selected from the group consisting of: chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl group; acetyl, benzoyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; and / or Where R 10 To R 13 At least one other substituent is selected from the group consisting of: sulfonic acids or their salts; carboxylic acids or their salts; boric acids or their salts; phosphonic acids or their salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl groups, two R's can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; (meth)acrylates; toluenesulfonyl groups; NH2; and OH.

18. The spiropyran according to claims 16 to 17, wherein R 10 To R 13 At least one of the following is selected from one of the following formulas: , , , , , , and , Where R 14 To R 27 As defined in claim 16, and Where R 2 To R 5 At least one of them is selected from the group consisting of: chlorine; bromine; iodine; formyl; carbonate; carbonate; ester; amide; CF3; substituted or unsubstituted C2-C 49 Alkyl acyl; substituted or unsubstituted C2-C 49 Aryl acyl; ketone; acyl group; acetyl, benzoyl; oxime; aldehyde; NO2; CN; (meth)acrylate; sulfone; alkyl sulfone; sulfonamide; SO2Me; SO2NH2; methoxy; and toluenesulfonyl; and / or Where R 2 To R 5 At least one other substituent is selected from the group consisting of: sulfonic acids or their salts; carboxylic acids or their salts; boric acids or their salts; phosphonic acids or their salts; NR'3 + R' is independently selected from H, D, substituted or unsubstituted C1-C 20 Alkyl and substituted or unsubstituted C6-C 48 Aryl groups, two R's can form a ring structure; substituted or unsubstituted sulfonates; substituted or unsubstituted sulfonamides; phosphonates; phosphine; phosphates / esters; sulfinic acids; sulfinates; sulfonates; sulfoxides; sulfones; alkyl sulfones; oximes; isocyanates; cyanates; isocyanates; thiocyanates; isothiocyanates; ammonium; substituted or unsubstituted carbamates; (meth)acrylates; toluenesulfonyl groups; NH2; and OH.

19. The spiropyran according to claims 16 to 18, wherein R 2 To R 5 At least one of them and another R 10 To R 13 At least one of them is a substituent selected from one of the following formulas: , , , , , , and , Where R 14 To R 27 As defined in claim 16, and / or Where R 2 To R 5 The selected substituents on one of them and R 10 To R 13 The selected substituents on one are different. and / or Where R 10 and R 12 To R 13 At least one of them is a substituent selected from one of the following formulas: , , , , , , and , Where R 14 To R 27 As defined in claim 16.

20. The spiropyran according to any one of claims 16 to 19, wherein R 2 R 3 R 5 and R 10 To R 13 At least two substituents are independently selected from Or electron-withdrawing groups.

21. The spiropyran according to any one of claims 16 to 20, wherein R 2 To R 5 R 10 R 12 R 13 At least two substituents are independently selected from Or electron-withdrawing groups.

22. The spiropyran according to any one of claims 16 to 21, wherein R 2 To R 5 One of them is And R 10 To R 13 One of them is , where R 19 same.

23. The spiropyran according to any one of claims 16 to 22, wherein R 2 To R 5 One of them is And R 10 To R 13 One of them is , where R 19 different.

24. The spiropyran according to any one of claims 16 to 23, wherein R 2 To R 5 It is an electron-withdrawing group. and / or Where R 4 R 10 R 12 R 13 At least one of them is R 12 R 13 At least one of them is And more preferably R 13 for .

25. The spiropyran according to any one of claims 16 to 24, wherein R 2 To R 5 At least one of them is a substituted or unsubstituted aryl acyl group, and R 10 To R 13 At least one of them is a substituted or unsubstituted alkyl acyl group.

26. The spiropyran according to any one of claims 16 to 25, wherein R 4 It is an electron-withdrawing group, and R 13 for .

27. The spiropyran according to any one of claims 16 to 26, wherein R 11 It is H or an electron-withdrawing group.

28. The spiropyran according to any one of claims 16 to 27, wherein R 2 To R 5 and R 10 To R 13 At least one of them is a substituted aryl acyl group and contains an electron-withdrawing group as a substituent, preferably the substituent is selected from CN, CF3, F, Cl, Br, I, OCF3, substituted or unsubstituted alkyl esters, substituted or unsubstituted aryl esters, SO2Me and SO2NH2.

29. The spiropyran according to any one of claims 16 to 28, wherein R 1 Selected from the following group: H, D, substituted or unsubstituted C1-C6 alkyl, -CH2-CH2-OH, -CH2-COOH, -CH2-CH2-COOH, -CH2-CH2-CH2-nMe3 + -CH2-CH2-CH2-SO3 - phenyl and benzyl, preferably R 1 It can be methyl, -CH2-CH2-OH, phenyl or benzyl, -CH2-COOH, -CH2-CH2-COOH, or -CH2-CH2-CH2-nMe3. + and -CH2-CH2-CH2-SO3 - .

30. A method for locally polymerizing a starting material by using a spiropyran according to any one of claims 16 to 29 as a photoinitiator and irradiating the spiropyran with light of at least one wavelength, preferably with light of at least two different wavelengths.

31. A method for locally polymerizing a starting material via two-color photopolymerization, the method comprising: Provided a polymerizable starting material containing a photoinitiator molecule, wherein the photoinitiator molecule is a spiropyran according to any one of claims 16 to 29, which is capable of being sequentially photoexcited to a reactive state, wherein the photoinitiator molecule locally triggers the polymerization of the starting material; and By irradiating a local volume with light of a first wavelength and light of a second wavelength different from the first wavelength, the starting material within the local volume is photopolymerized, thereby achieving [the desired effect] within the local volume. The photoinitiator molecule, due to absorbing light of the first wavelength, transitions from an initial state where it substantially does not absorb light of the second wavelength to an intermediate state with altered optical properties compared to the initial state, such that the photoinitiator molecule in the intermediate state absorbs light of the second wavelength; and The photoinitiator molecule transforms from the intermediate state to the reactive state by absorbing light of the second wavelength, thereby locally triggering the polymerization.

32. A method for forming a molded article by two-color photopolymerization, the method comprising: Provided a polymerizable starting material containing a photoinitiator molecule, wherein the photoinitiator molecule is a spiropyran according to any one of claims 16 to 29, which is capable of being sequentially photoexcited to a reactive state, wherein the photoinitiator molecule locally triggers the polymerization of the starting material; and By irradiating a local volume with light of a first wavelength and light of a second wavelength different from the first wavelength, the starting material within the local volume is photopolymerized, thereby achieving [the desired effect] within the local volume. The photoinitiator molecule, due to absorbing light of the first wavelength, transitions from an initial state where it substantially does not absorb light of the second wavelength to an intermediate state with altered optical properties compared to the initial state, such that the photoinitiator molecule in the intermediate state absorbs light of the second wavelength; and The photoinitiator molecule transitions from the intermediate state to the reactive state by absorbing light of the second wavelength, thereby locally triggering the polymerization; and The photoinitiator molecules are able to spontaneously transition from the intermediate state to the initial state during a thermal reaction.

33. The method according to any one of claims 30 to 32, the method further comprising the step of providing a post-processing step on the molded article, wherein the post-processing includes heat treatment and / or optical treatment of the molded article.

34. The method of claim 30 or 33, the method further comprising the step of forming a three-dimensional object from the molded body by removing the molded body from the polymerizable starting material.

35. The method of claim 34, wherein post-processing of the three-dimensional object comprises altering the optical properties of the three-dimensional object such that the absorption properties of the three-dimensional object for at least one wavelength in the wavelength range of 300 nm to 2000 nm are reduced, and / or the projection properties of the three-dimensional object for at least one wavelength in the wavelength range of 300 nm to 2000 nm are increased.

36. The method according to any one of claims 30 to 35, wherein the optical processing is performed by irradiating light having a certain intensity and wavelength, the irradiation not removing the three-dimensional object from the polymerizable material.

Images