Modified Thioxanthone Photoinitiator

Abstract

Latent photoinitiator compounds are described, as well as compositions containing such compounds and their use in photoinitiation processes for producing photoresist structures.

Description

[Technical Field]

[0001] The present invention relates to substituted thioxanthone derivatives and dimers thereof in which the carbonyl group is blocked by a cyclic ketal, or a substituted or unsubstituted 1,3-dioxolane, or a substituted or unsubstituted 1,3-dioxane, or a substituted or unsubstituted 1,3-dioxonane group, and the use of such derivatives in photoinitiated reactions. The invention also relates to synthetic methods for making these and other substituted thioxanthone derivatives. [Background technology]

[0002] Light-absorbing ketone compounds are well known for use in photoinduced reactions. These species, commonly referred to as photoinitiators or photosensitizers, generate reactive species upon exposure to radiation. Examples of such photoinitiators or photosensitizers can be found in U.S. Pat. No. 7,585,611B, European Patent Application No. 2,792,694A1, and U.S. Pat. No. 7,425,585B. When incorporated into a suitable convertible substrate, the reactive species generated by exposure to radiation, optionally in combination with other species, can directly or indirectly trigger a chemical reaction in the convertible substrate via sensitization and energy or electron transfer processes. Typically, the convertible substrate contains an organic material that can be a monomer, oligomer, polymer, or mixture thereof, that is converted into a new polymeric material.

[0003] In some applications, it is desirable to block one or more ketone moieties of a ketone photoinitiator so that the photoinitiator is latent and can be activated by unblocking. U.S. Patent Application Publication No. 2004 / 0014833 and WO 2011 / 086389 relate to such protected ketone photoinitiators and methods of using them.

[0004] The present invention relates to blocked or latent ketone photoinitiators that are improvements over those known in the art. In particular, the blocked or latent ketone photoinitiators of the present invention, which have specific substituents on the cyclic ketal and specific substituents and / or protecting groups on the carbon backbone of the thioxanthone, have been found to have properties that make them desirable in a variety of applications. These properties include an increased differential solubility of at least the deprotected species in aqueous or organic development media compared to unsubstituted photoinitiators.

[0005] Unless otherwise specified, a "blocked" ketone photoinitiator, as used herein, refers to a latent ketone photoinitiator in which the ketone group is blocked by reaction of a ketone with a diol to form a 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane group, or by reaction of a ketone with a tetraol to form a dimer, wherein two photoinitiator molecules are linked such that each ketone forms a 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane group, respectively, by a linker between the two ketal moieties or by two ketal moieties fused together along a carbon-carbon bond. As used herein, a "blocked" ketone photoinitiator refers to a latent ketone photoinitiator dimer in which the ketone group of each monomer is blocked by reaction of the ketone with a substituted diol to form a substituted 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane group, where the substituent on the diol is a reactive substituent capable of reacting with itself to form a dimer. Consequently, references herein to "unblocked" or "deblocked" ketone photoinitiators are references to active ketone photoinitiator monomers in which a carbonyl is present in place of the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane group. Unless otherwise specified, reference herein to a "protected" ketone photoinitiator is a reference to a compound having a functional group present on the aromatic ring of the photoinitiator, which functional group has been modified by the inclusion of a protecting group. For example, acetal, alkyl carbonate, and ester substituents are protecting groups for the underlying hydroxyl group, so a compound having one of these protecting groups as a substituent can be referred to as a protected ketone photoinitiator.

[0006] One particular application of the blocked ketone photoinitiator for which the compounds of the present invention are suitable is as a component of a photoresist composition. Photoresists are photosensitive compositions used in many industrial processes and have particularly important applications in the electronics industry. Typically, a photoresist composition is coated on a substrate to form a photoresist layer. Selected areas of the layer are then exposed to electromagnetic energy, usually light energy such as UV, deep UV, KrF or ArF excimer laser light, EUV light, or electron beam (EB), to initiate a chemical reaction in the exposed areas of the photoresist. A photoresist developer is then used to remove materials soluble in the developer. The photoresist can be in the form of a negative photoresist or a positive photoresist. A positive photoresist is a photoresist in which the exposed portions of the photoresist become soluble in the photoresist developer and can therefore be removed by the developer, while the unexposed portions of the photoresist remain insoluble in the photoresist developer. A negative photoresist is one in which the exposed portions of the photoresist are rendered insoluble in the photoresist developer, while the unexposed portions of the photoresist are dissolved and can be removed by the photoresist developer. After the developer step, a patterned coating remains on the surface that is insoluble in the developer. Further steps, such as a curing step, which can be performed by the application of heat or exposure to further light, can be performed to harden the coating.

[0007] When the soluble portions of the photoresist that are removed by the developer have very fine features, as is generally the case with positive photoresists, it is important that the species present in the removed areas be soluble in the developing medium, which is typically an aqueous medium. Otherwise, so-called "scumming" can occur. The latent or blocked photoinitiators described herein can be advantageously used in such photoinitiation methods. Summary of the Invention

[0008] According to the present invention, there is provided a compound of formula I:

[0009] [ka]

[0010] In the formula, n=0 or 1, m=0, 1, 2 or 3, R1 and R2 are C 1-6 Alkyl hydroxy group or its carboxylate ester, C 1-6 Alkylthio group and C 1-6 Alkylamino group, ester part is C 1-6 C containing alkyl groups and / or 4- to 10-membered carbocyclic groups 1-6 carboxylate ester groups; and R3, R4, R5, R6, R7 and R8 are independently selected from H, a hydroxy group, C 1-6 Alkyl group, C 2-6 Alkenyl group, C 1-6 Alkoxy group, C 1-6 Alkylthio group, 4- to 8-membered carbocyclic group, 4- to 8-membered heterocyclic group, ester moiety is C 1-6 C containing alkyl groups and / or 4- to 10-membered carbocyclic groups 1-6 carboxylate ester groups, or R5 together with R3 or R7 form a 4- to 8-membered carbocyclic group or a 4- to 8-membered heterocyclic group.

[0011] In some embodiments, R3, R4, R5, R6, R7, and R8 are C 1-6 Alkyl group, C 2-6 Alkenyl group, C 1-6 Alkoxy group, C 1-6 Alkylthio group, 4- to 8-membered carbocyclic group, 4- to 8-membered heterocyclic group, ester moiety is C 1-6 C containing alkyl groups and / or 4- to 10-membered carbocyclic groups 1-6 carboxylate ester groups, or R5 together with R3 or R7 form a 4- to 8-membered carbocyclic or 4- to 8-membered heterocyclic group, the selected groups being halogen, hydroxyl, mercapto, nitro, cyano, formyl, carboxyl, trifluoromethyl, trifluoromethoxy, amino, oxo, imino, C 1-6 Alkyl (e.g., methyl), C 1-6Alkoxy (e.g., methoxy), heteroaryl, phenyl, or halogen, hydroxyl, mercapto, nitro, cyano, formyl, carboxyl, trifluoromethyl, trifluoromethoxy, amino, oxo, imino, C 1-6 Alkyl (e.g., methyl) or C 1-6 Optionally further substituted with one or more substituents selected from phenyl or heteroaryl substituted with one or more of alkoxy (eg, methoxy).

[0012] In some embodiments, the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane ring can be unsubstituted. In some embodiments, R, R, R, R, R, R, and R can be selected such that the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane ring is substituted with one or more substituents. In some embodiments, R, R, R, R, R, R, and R can be selected such that the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane ring is substituted with two or more substituents in any substitution pattern, such as geminal, vicinal, or other.

[0013] Thus, in some examples, one or more of R, R, R, R, R, R, and R can independently be (chloro)alkyl, and C 1-6 (Chloro)alkyl, such as (chloro)methyl, (chloro)ethyl, (chloro)propyl, and also (chloro)cycloalkyl, for example, where two substituents on the 1,3-dioxane ring may be joined to form a cyclic group, such as a 5- or 6-membered carbocyclic ring fused to the 1,3-dioxane ring. In some examples, the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane ring may contain one or more C substituted or unsubstituted carbon atoms in any substitution pattern. 1-6 Alkyl groups, e.g., two or more C 1-6For example, a 1,3-dioxolane ring, a 1,3-dioxane ring, a 1,3-dioxepane ring, a 1,3-dioxocane ring, or a 1,3-dioxonane ring may be substituted with a geminal or vicinal C 1-6 It may be substituted with an alkyl group, such as a geminal or vicinal methyl group. In some examples, the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane ring may be substituted with one, two, three, or four C 1-6 It may be substituted with alkyl groups, for example, 1, 2, 3 or 4 methyl groups. In all of the above examples, C 1-6 Alkyl is understood to include methyl, ethyl, propyl, butyl, pentyl and hexyl, and all positional isomers thereof.

[0014] In some instances, the compounds of the invention are other than compounds of Formula I and can be based on the same thioxantone ketone photoinitiator, where the ketone is blocked by a cyclic ketal linked by a linker group to another cyclic ketal-blocked thioxantone ketone photoinitiator, for example, a compound where the ketone is "blocked" by a six-membered cyclic acetal, such as 1,3-dioxane, and linked to another thioxantone ketone photoinitiator by a linker, such as an ethylene or vinyl bridge, to another ketone that is also "blocked" by a six-membered cyclic acetal, such as 1,3-dioxane. In some instances, such compounds can be described as dimers of compounds of Formula I, for example, compounds of Formula II:

[0015] [ka]

[0016] wherein m=0, 1, 2, 3 or 4; One of the aromatic rings is -OC (1-6) Alkylhydroxy group or its carboxylate ester, -OC (1-6) Alkylthio group and -OC (1-6) Alkylamino group, ester part is C 1-6-OC containing alkyl groups and / or 4- to 10-membered carbocyclic groups (1-6) 3,4-disubstituted with substituents independently selected from carboxylate ester groups; or one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio; and L=linker group.

[0017] In some embodiments, L is a single bond, -C 1-6 Alkyl- or C 2-6

[0023] L is an -alkenyl or phenyl ring, which may be substituted. In some examples, L is a carbon-carbon bond that fused two monomers together so that they share a common carbon-carbon bond between the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane groups, respectively. In some examples, L is a phenyl ring fused to each monomer so that they share a common carbon-carbon bond with the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane groups, respectively. In some examples, L is a phenyl ring that formed a new carbon-carbon bond with the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane groups, respectively. In some examples, L is a carbon atom common to the 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane groups of each monomer so as to form a spiro center.

[0018] Thus, in some instances, L is a single bond, C, which may each be substituted. 1-6 Alkyl group, C 2-6or L comprises a fused carbon-carbon bond shared between 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane groups, respectively; or L comprises a carbon atom shared between 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane groups, respectively.

[0019] Unless otherwise stated, when a stereocenter exists in any of the compounds described or claimed herein, the compounds exist in racemic form.

[0020] In one embodiment, one of the aromatic rings is substituted with at least one (e.g., 1, 2, 3, or 4) substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio, and the other aromatic ring is unsubstituted. In another embodiment, each aromatic ring is substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio.In this embodiment, each ring is substituted with a single substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio; or one of the rings is substituted with two substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio and the other ring is substituted with a single substituent selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio; or one of the rings is substituted with hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio. , acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio, and the other ring is substituted with a single substituent selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio, or one ring is substituted with four substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio, and the other ring is substituted with a single substituent selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio.

[0021] In other embodiments, each aromatic ring is substituted with at least two substituents, e.g., at least three substituents, e.g., four substituents, each independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0022] The present invention also provides (a) a compound of formula I or II as defined above; and (b) chemically transformable substrates; wherein the compound of formula I or II is a precursor to a reactive derivative of formula III:

[0023] [ka]

[0024] The compounds of formula III have the same substitution pattern as the compounds of formula I or II and can be obtained by reacting the compounds of formula I or II in the presence of an acid; Additionally, the convertible substrate can be converted in the presence of a compound of formula III by direct or indirect photoinitiation.

[0025] In some instances, compounds of formula III having the same substitution pattern as compounds of formula I or II can be obtained by reacting compounds of formula I or II in the presence of an acid by thermal treatment.

[0026] By "reactive derivative" is meant a ketal, e.g., a cyclic ketal such as a 1,3-dioxolane, or 1,3-dioxane, or 1,3-dioxepane, or 1,3-dioxocane, or 1,3-dioxonane moiety, that is cleaved by acid treatment, with or without heat, to make available a carbonyl group that provides a reactive functionality in the photoinitiation method described below.

[0027] The composition of the present invention comprises: (a) forming a layer of the composition on a substrate; (b) applying an acid or generating an acid in situ to selected areas of the layer and reacting the acid with a compound of formula I or II to form a reactive derivative of formula III in the selected areas of the layer; (c) exposing the layer having the reactive derivative present in selected areas to electromagnetic radiation of a wavelength or energy suitable to generate a reactive species from the compound of formula III; and (d) directly or indirectly causing the conversion of a substrate that can be converted into a reactive species; The photoinitiated method may be used in a photoinitiated method including:

[0028] In some embodiments, allowing the acid to react with the compound of Formula I or II to form the reactive derivative of Formula III can include the application of heat, which can be simultaneous with the application of the acid or in situ generation of the acid, or can be subsequent to this step.

[0029] In some embodiments, the method may further include performing a post-conversion heat treatment.

[0030] The temperature of either or both of these heat treatments may range from 70° C. to 170° C. The duration of either or both of these heat treatments may range from 2 minutes to 120 minutes. It is understood that the temperatures and times are given by way of example only and should not be considered limiting in any way.

[0031] In some embodiments, the reactive derivative of formula III includes a compound of formula IIIa:

[0032] [ka]

[0033] In the formula, R1 and R2 are C 1-6 Alkylhydroxy group, C 1-6 Alkylthio group and C 1-6 Alkylamino group, C 1-6 carboxylic acid groups.

[0034] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0035] In some embodiments, reactive derivatives of formula III include compounds of formula III wherein one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0036] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0037] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0038] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, oxyacetic acid and its esters, aryloxy, and arylthio.

[0039] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid, aryloxy, and arylthio.

[0040] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, oxyacetic acid, aryloxy, and arylthio.

[0041] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, acetal, ester, oxyacetic acid, aryloxy, and arylthio.

[0042] In some embodiments, reactive derivatives of formula III include compounds of formula III wherein one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0043] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, ester, oxyacetic acid, aryloxy, and arylthio.

[0044] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, oxyacetic acid and its esters, aryloxy, and arylthio.

[0045] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid, aryloxy, and arylthio.

[0046] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, acetal, oxyacetic acid and its esters, aryloxy, and arylthio.

[0047] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0048] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0049] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, acetal, oxyacetic acid and its esters, aryloxy, and arylthio.

[0050] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, oxyacetic acid, aryloxy, and arylthio.

[0051] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, acetal, oxyacetic acid, aryloxy, and arylthio.

[0052] In some embodiments, reactive derivatives of formula III include compounds of formula III wherein one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, ester, oxyacetic acid, aryloxy, and arylthio.

[0053] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, oxyacetic acid and its esters, aryloxy, and arylthio.

[0054] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, acetal, oxyacetic acid, aryloxy, and arylthio.

[0055] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, ester, oxyacetic acid, aryloxy, and arylthio.

[0056] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, oxyacetic acid and esters thereof, aryloxy, and arylthio.

[0057] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, acetal, ester, oxyacetic acid, aryloxy, and arylthio.

[0058] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, acetal, oxyacetic acid and its esters, aryloxy, and arylthio.

[0059] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0060] In some embodiments, reactive derivatives of formula III include compounds of formula III wherein one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, hydroxyalkyl, oxyacetic acid, aryloxy, and arylthio.

[0061] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, oxyacetic acid, aryloxy, and arylthio.

[0062] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, acetal, oxyacetic acid, aryloxy, and arylthio.

[0063] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, ester, oxyacetic acid, aryloxy, and arylthio.

[0064] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, oxyacetic acid and its esters, aryloxy, and arylthio.

[0065] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, alkylcarbonate, hydroxyalkyl, oxyacetic acid and esters thereof, aryloxy, and arylthio.

[0066] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, acetal, oxyacetic acid and its esters, aryloxy, and arylthio.

[0067] In some embodiments, reactive derivatives of formula III include compounds of formula III in which one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, ester, oxyacetic acid and its esters, aryloxy, and arylthio.

[0068] In some embodiments, reactive derivatives of formula III include compounds of formula III where one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, hydroxyalkyl, oxyacetic acid, aryloxy, and arylthio.

[0069] For the avoidance of doubt, the reference in the preceding paragraph to "one or both of the aromatic rings substituted with at least one substituent independently selected from ..." refers to a situation in which each of the aromatic rings is mono-, di-, tri-, or tetra-substituted with a substituent independently selected from any of the lists provided herein. It will be understood that the same reference applies equally to situations in which one ring has one substituent and the other has two, three, or four substituents, or one ring has two substituents and the other has three or four substituents, in all cases with substituents independently selected from any of the lists provided herein.

[0070] In some embodiments of the present invention, the compounds of the present invention have good solubility in aqueous media, making them suitable for use in photoinitiated processes in which the compounds remain after conversion of the chemically convertible substrate and must be removed by an aqueous developer.

[0071] In another embodiment, the compounds of the present invention have much better solubility in aqueous media after deprotection, making them suitable for use in photoinitiated processes where the compounds themselves, especially their deprotected forms, remain after conversion of the chemically convertible substrate and must be removed by an aqueous developer resulting in improved contrast and better image quality after development. DETAILED DESCRIPTION OF THE INVENTION

[0072] Compounds of the Invention In a first aspect, the present invention provides a compound of formula I:

[0073] [ka]

[0074] In the formula, n=0 or 1, m=0, 1, 2 or 3, R1 and R2 are C 1-6 Alkylhydroxy group, C1-6 Alkylthio group and C 1-6 R3, R4, R5, R6, R7 and R8 are independently selected from H, a hydroxy group, C 1-6 Alkyl group, C 1-6 Alkoxy group, C 1-6 R5 is independently selected from an alkylthio group, a 4- to 8-membered carbocyclic group, or a 4- to 8-membered heterocyclic group, or R5 together with R3 or R7 forms a 4- to 8-membered carbocyclic group or a 4- to 8-membered heterocyclic group.

[0075] The present invention also provides compounds of formula II:

[0076] [ka]

[0077] wherein m=0, 1, 2, 3 or 4, and one of the aromatic rings is -OC at the 3- and 4-positions of the thioxanthone ring. (1-6) Alkylhydroxy group or its carboxylate ester, -OC (1-6) Alkylthio group and -OC (1-6) Alkylamino group, ester part is C 1-6 -OC containing alkyl groups and / or 4- to 10-membered carbocyclic groups (1-6) disubstituted with substituents independently selected from carboxylate ester groups; or one or both of the aromatic rings are substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio; L = linker group.

[0078] In one embodiment, one of the aromatic rings is substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its esters, aryloxy, and arylthio, and the other aromatic ring is unsubstituted. For example, one ring may be substituted with a single substituent selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio; or it may be substituted with two substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio; or it may be substituted with three substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio; or it may be substituted with four substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio.

[0079] In another embodiment, each aromatic ring is substituted with at least one substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio. For example, each ring can be substituted with a single substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio, or one ring can be substituted with two substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio, and the other ring is substituted with a single substituent independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio, or one ring can be substituted with hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and esters thereof, aryloxy, and arylthio. One ring is substituted with three substituents independently selected from acetal, ester, oxyacetic acid and its ester, aryloxy and arylthio, and the other ring is substituted with a single substituent selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its ester, aryloxy and arylthio, or one ring is substituted with four substituents independently selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its ester, aryloxy and arylthio, and the other ring is substituted with a single substituent selected from hydroxy, alkoxy, benzyloxy, alkylcarbonate, hydroxyalkyl, acetal, ester, oxyacetic acid and its ester, aryloxy and arylthio.

[0080] In the compounds of the present invention, alkyl is C 1-6It can be alkyl, such as methyl or hexyl. In some examples, the alkyl can be selected from methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, neohexyl.

[0081] In the compounds of the present invention, alkoxy is C 1-6 The alkoxy may be, for example, methoxy or hexoxy. In some examples, the alkoxy may be selected from methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, t-butoxy, pentoxy, isopentoxy, neopentoxy, hexoxy, isohexoxy, and neohexoxy. In some examples, the compounds of the present invention have two or more methoxy substituents on the aromatic ring. In some examples, the compounds of the present invention have methoxy substituents on each aromatic ring. In some examples, the compounds of the present invention have two methoxy substituents on one of the aromatic rings. In some examples, the compounds of the present invention do not include any 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepane, 1,3-dioxocane, or 1,3-dioxonane derivatives of 2-methoxy-9H-thioxanthen-9-one or 3,6-dimethoxy-9H-thioxanthen-9-one falling within the scope of Formula (I).

[0082] For example, in the compounds of the invention relating to R1 and / or R2 of formula (I), alkylhydroxy is 1-6 It may be an alkylhydroxy group, e.g., ethylhydroxy. Thus, in compounds of formula (I) of the invention where R1 and / or R2 are alkylhydroxy, the substituents OR1 and OR2 on the thioxanthone ring are understood to refer to the general formula -OROH, which may be derived, for example, from ethylene glycol. The carboxylate ester is understood to include the addition of a carboxylic acid, e.g., acetic acid, to the terminal hydroxy group such that it conforms to the general formula -OROC(O)R'.

[0083] In the compounds of the present invention, alkylthio is C 1-6-alkylthio group, for example ethanethiol. Thus, in compounds of the invention of formula (I) where R1 and / or R2 are alkylthio, the substituents OR1 and OR2 on the thioxanthone ring are understood to relate to the general formula -ORSH.

[0084] In the compounds of the present invention, alkylamino is C 1-6 It may be an alkylamino group, for example aminoethane. Thus, in compounds of the invention of formula (I) where R and / or R are alkylamino, the substituents OR and OR on the thioxanthone ring are understood to relate to the general formula -ORNH.

[0085] In the compounds of the present invention, the alkyl carbonate is C 1-6 It may be an alkyl carbonate, for example t-butoxy carbonate.

[0086] In the compounds of the present invention, the ester is C 1-4 The orthoester may be an alkyl acid ester, such as an acetic acid ester or an ester of trifluoromethanesulfonic acid. In some instances, the ester may be an orthoester in which adjacent carbon atoms in the ring are bonded to respective oxygen atoms, thereby forming a 5- or 6-membered cyclic orthoester. The cyclic orthoester may be derived from trimethyl, triethyl, or tripropyl orthoformate, such as triisopropyl orthoformate. For example, in the case of trimethyl orthoformate, the resulting cyclic orthoester is 2-methoxybenzo[1,3]dioxole.

[0087] In compounds of the invention, the acetal can be a C alkoxyalkyl group, such as methoxymethyl or ethoxyethyl. In some instances, the acetal can be a cyclic acetal in which adjacent carbon atoms of the ring are bonded to respective oxygen atoms, thereby forming a 5- or 6-membered cyclic acetal.

[0088] In the compounds of the present invention, benzyloxy may be a benzyloxy group, including substituted or unsubstituted benzyl groups. The substituents may be selected from the group consisting of C alkyl, e.g., methyl or ethyl, hydroxy, alkoxy, alkyl carbonate, acetal, and ester.

[0089] In the compounds of the present invention, the oxyacetic acid and esters thereof may be oxyacetic acid or an ester thereof, such as an oxyacetic acid ester in which the esterifying group is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, isonorbornyl, 2-methyl-2-adamantyl, 3-tetrahydrofuranyl 3-oxocyclohexyl, γ-butyrolactone-3-yl, mevalonate lactone, γ-butyrolactone-2-yl, 3-methyl-γ-butyrolactone-3-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, 2,3-propylcarbonate-1-yl, vinyl ether addition products, such as ethoxyethyl, methoxyethoxyethyl, or acetoxyethoxyethyl.

[0090] In the compounds of the present invention, aryloxy can be optionally substituted C5 or C6 aryloxy, such as phenoxy. In the compounds of the present invention, arylthio can be optionally substituted C5 or C6 arylthio, such as phenylthio. The substituents can be selected from the group consisting of C1-6 alkyl, such as methyl or ethyl, hydroxy, alkoxy, alkyl carbonate, acetal, and ester.

[0091] In the compounds of the present invention, the 4- to 8-membered carbocyclic group may be an unsubstituted (un)saturated carbocycle, such as cyclobutane / ene or cyclooctane / ene. In some examples, the 4- to 8-membered carbocyclic group may be selected from cyclopentane / ene, cyclohexane / ene, and cycloheptane / ene. In some examples, the 4- to 8-membered carbocyclic group may be a substituted (un)saturated carbocycle, such as methylcyclobutane / ene or methylcyclooctane / ene. In some examples, the 4- to 8-membered carbocyclic group may be selected from methylcyclopentane / ene, methylcyclohexane / ene, and methylcycloheptane / ene. In some examples, the 4- to 8-membered carbocyclic group may be an unsubstituted aromatic carbocycle, such as benzene. In some examples, the 4- to 8-membered carbocyclic group may be a substituted aromatic carbocycle, such as toluene. In some examples, the substituted aromatic carbocycle may contain one or more C 1-6 Alkyl groups, e.g., two or more C 1-6 For example, a substituted aromatic carbocycle can be C 1-6 It may be substituted with an alkyl group, for example, an adjacent methyl group.

[0092] In the compounds of the present invention, the 4- to 10-membered carbocyclic group can be an unsubstituted saturated carbocyclic ring, such as adamantane. In some examples, the 4- to 10-membered carbocyclic group can be a substituted saturated carbocyclic ring, such as methyladamantane.

[0093] In the compounds of the present invention, the 4- to 8-membered heterocyclic group may be an unsubstituted (un)saturated heterocycle, such as azetidine or azocane. In some examples, the 4- to 8-membered heterocyclic group may be selected from pyrrolidine, piperidine, azepane, oxetane, tetrahydrofuran, tetrahydropyran, oxepane, oxocane, thietane, tetrahydrothiophene, thiane, thiepane, and thiocane. In some examples, the 4- to 8-membered heterocyclic group may be a substituted (un)saturated heterocycle, such as methylazetidine or methylazocane. In some examples, the 4- to 8-membered heterocyclic group may be selected from methylpyrrolidine, methylpiperidine, methylazepane, methyloxetane, methyltetrahydrofuran, methyltetrahydropyran, methyloxepane, methyloxocane, methylthietane, methyltetrahydrothiophene, methylthiane, methylthiepane, and methylthiocane. For the avoidance of doubt, unsaturated equivalents of the 4- to 8-membered heterocyclic groups listed above are also included. It is further understood that unsaturation means at least one double bond, if not more. It is further understood that unsaturation includes aromatic heterocycles, such as pyrrole, furan, and thiophene. In the above examples, it is further understood that the term "heterocycle" or "heterocyclic" refers to a ring molecule that may contain at least one heteroatom, if not more, such as pyrazine and thiazole.

[0094] In some embodiments of the present invention, all of the substituents on the aromatic ring may be the same.

[0095] In some embodiments of the present invention, the 1,3-dioxolane ring may be substituted with one or more substituents selected from alkyl, ester, cycloalkyl, cycloalkenyl, haloalkyl, aryl, heteroaryl, or vinyl in any substitution pattern described herein. In some examples, the alkyl may be C 1-6(chloro)alkyl, such as (chloro)methyl, (chloro)ethyl, (chloro)propyl, and also (chloro)cycloalkyl and aryl, where two substituents on the 1,3-dioxolane ring may be joined to form a cyclic group, such as a 5- or 6-membered carbocyclic ring fused to the 1,3-dioxolane ring. In some examples, the 1,3-dioxolane ring may contain one or more C 1-6 Alkyl groups, e.g., two or more C 1-6 For example, 1,3-dioxolane can be substituted with geminal or vicinal C alkyl groups in any substitution pattern. 1-6 In some examples, the 1,3-dioxolane ring may be substituted with one, two, three, or four C alkyl groups, such as geminal or vicinal methyl groups. 1-6 It may be substituted with alkyl groups, for example, 1, 2, 3 or 4 methyl groups. In all of the above examples, C 1-6 Alkyl is understood to include methyl, ethyl, propyl, butyl, pentyl and hexyl and all positional isomers thereof.

[0096] In some embodiments of the present invention, the 1,3-dioxane ring may be substituted with one or more substituents selected from alkyl, ester, cycloalkyl, cycloalkenyl, haloalkyl, aryl, heteroaryl, or vinyl in any substitution pattern. In some examples, alkyl is C 1-6 (chloro)alkyl, such as (chloro)methyl, (chloro)ethyl, (chloro)propyl, and also (chloro)cycloalkyl and aryl, where two substituents on the 1,3-dioxane ring may be joined to form a cyclic group, such as a 5- or 6-membered carbocyclic ring fused to the 1,3-dioxane ring. In some examples, the 1,3-dioxane ring may contain one or more C 1-6 Alkyl groups, e.g., two or more C 1-6 For example, 1,3-dioxane can be substituted with geminal or vicinal C groups in any substitution pattern. 1-6 In some examples, the 1,3-dioxane ring may be substituted with one, two, three, or four C alkyl groups, such as geminal or vicinal methyl groups. 1-6It may be substituted with alkyl groups, for example, 1, 2, 3 or 4 methyl groups. In all of the above examples, C 1-6 Alkyl is understood to include methyl, ethyl, propyl, butyl, pentyl and hexyl and all positional isomers thereof.

[0097] In some embodiments of the present invention, the 1,3-dioxepane ring may be substituted with one or more substituents selected from alkyl, ester, cycloalkyl, cycloalkenyl, haloalkyl, aryl, heteroaryl, or vinyl in any substitution pattern. 1-6 (Chloro)alkyl, such as (chloro)methyl, (chloro)ethyl, (chloro)propyl, and also (chloro)cycloalkyl and aryl, where two substituents on the 1,3-dioxepane ring may be joined to form a cyclic group, such as a 5- or 6-membered carbocyclic ring fused to the 1,3-dioxepane ring. In some examples, the 1,3-dioxepane ring may contain one or more C 1-6 Alkyl groups, e.g., two or more C 1-6 For example, 1,3-dioxepane can be substituted with either geminal or vicinal C groups in any substitution pattern. 1-6 It may be substituted with alkyl groups, such as geminal or vicinal methyl groups. In some examples, the 1,3-dioxepane ring may be substituted with 1, 2, 3, or 4 C 1-6 It may be substituted with alkyl groups, for example, 1, 2, 3 or 4 methyl groups. In all of the above examples, C 1-6 Alkyl is understood to include methyl, ethyl, propyl, butyl, pentyl and hexyl and all positional isomers thereof.

[0098] In some embodiments of the present invention, the 1,3-dioxocane ring may be substituted with one or more substituents selected from alkyl, ester, cycloalkyl, cycloalkenyl, haloalkyl, aryl, heteroaryl, or vinyl in any substitution pattern. In some examples, alkyl is C 1-6(Chloro)alkyl, such as (chloro)methyl, (chloro)ethyl, (chloro)propyl, and also (chloro)cycloalkyl and aryl, where two substituents on the 1,3-dioxocane ring may be joined to form a cyclic group, such as a 5- or 6-membered carbocyclic ring fused to the 1,3-dioxocane ring. In some examples, the 1,3-dioxocane ring may contain one or more C 1-6 Alkyl groups, e.g., two or more C 1-6 For example, 1,3-dioxocane can be substituted with geminal or vicinal C groups in any substitution pattern. 1-6 It may be substituted with alkyl groups, such as geminal or vicinal methyl groups. In some examples, the 1,3-dioxocane ring may be substituted with 1, 2, 3, or 4 C 1-6 It may be substituted with alkyl groups, for example, 1, 2, 3 or 4 methyl groups. In all of the above examples, C 1-6 Alkyl is understood to include methyl, ethyl, propyl, butyl, pentyl and hexyl and all positional isomers thereof.

[0099] In some embodiments of the present invention, the 1,3-dioxonane ring may be substituted with one or more substituents selected from alkyl, ester, cycloalkyl, cycloalkenyl, haloalkyl, aryl, heteroaryl, or vinyl in any substitution pattern. 1-6 (chloro)alkyl, such as (chloro)methyl, (chloro)ethyl, (chloro)propyl, and also (chloro)cycloalkyl and aryl, where two substituents on the 1,3-dioxonane ring may be joined to form a cyclic group, such as a 5- or 6-membered carbocyclic ring fused to the 1,3-dioxonane ring. In some examples, the 1,3-dioxonane ring may contain one or more C 1-6 Alkyl groups, e.g., two or more C 1-6 For example, 1,3-dioxonane can be substituted with geminal or vicinal C alkyl groups in any substitution pattern. 1-6 In some examples, the 1,3-dioxonane ring may be substituted with one, two, three, or four C alkyl groups, such as geminal or vicinal methyl groups. 1-6It may be substituted with alkyl groups, for example, 1, 2, 3 or 4 methyl groups. In all of the above examples, C 1-6 Alkyl is understood to include methyl, ethyl, propyl, butyl, pentyl and hexyl and all positional isomers thereof.

[0100] It will be understood that these examples are given by way of example only and are in no way limiting.

[0101] The compounds of the present invention may have good solubility in aqueous media before and after deprotection. This may be characterized by reference to the octanol-water partition coefficient, which may be calculated by various means. For example, preferred compounds of the present invention have a calculated logP (ClogP) or milogP of less than 4.5, preferably less than 4.0, as measured using Molinspiration cheminformatics software. In other cases, the compounds of the present invention may have improved solubility after deprotection.

[0102] The present invention also relates to deprotected and deblocked forms of compounds of formula I or II in which the ketal, such as the 1,3-dioxolane ketone blocking group, or the 1,3-dioxane ketone blocking group, or the 1,3-dioxepane ketone blocking group, or the 1,3-dioxocane ketone blocking group, or the 1,3-dioxonane ketone blocking group, the 1,3-dioxolane ketone blocking group and related linker, or the 1,3-dioxane ketone blocking group and related linker, or the 1,3-dioxepane ketone blocking group and related linker, or the 1,3-dioxocane ketone blocking group and related linker, or the 1,3-dioxonane ketone blocking group and related linker, has been removed, having formula III,

[0103] [ka]

[0104] The compounds of formula III have the same substitution pattern as the compounds of formula I or II, and the compounds can be obtained by reacting the compounds of formula I or II in the presence of an acid or in the presence of an acid and heat.

[0105] The compound of formula III can be obtained by reacting the compound of formula I or II in the presence of acid and heat. The acid treatment and heat treatment can be simultaneous or can be performed sequentially. For example, the compound of formula III can be obtained by first reacting the compound of formula I or II in the presence of acid, followed by a subsequent heat treatment.

[0106] Examples of compounds of formula (I), (II) and (III) of the present invention are listed below in Table 1, and selected compounds and their respective milogP values ​​are listed in Table 2.

[0107] [Table 1-1]

[0108] [Table 1-2]

[0109] [Table 1-3]

[0110] [Table 1-4]

[0111] [Table 1-5]

[0112] [Table 1-6]

[0113] [Table 1-7]

[0114] [Table 1-8]

[0115] [Table 1-9]

[0116] [Table 1-10]

[0117] [Table 1-11]

[0118] [Table 1-12]

[0119] [Table 2-1]

[0120] [Table 2-2]

[0121] [Table 2-3]

[0122] Compositions and photoinitiation methods In a second aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: A compound of formula I or II as defined above; and chemically convertible substrates; A composition comprising: Compounds of formula I or II are precursors to reactive derivatives of formula III:

[0123] [ka]

[0124] The compound of formula III has the same substitution pattern on the thioxanthene ring as the compound of formula I or II, and the compound of formula III can be obtained by reacting the compound of formula I or II in the presence of an acid; Additionally, the convertible substrate may be converted in the presence of a compound of formula III by direct or indirect photoinitiation.

[0125] In the compositions of the second aspect, the compounds of formula I or II may be precursors to reactive derivatives of compounds of formula III having any of the substitution patterns described above.

[0126] The compound of formula III can be obtained by reacting a compound of formula I or II in the presence of acid and heat. The acid treatment and heat treatment can be simultaneous or sequential. For example, the compound of formula III can be obtained by first reacting a compound of formula I or II in the presence of acid, followed by a subsequent heat treatment.

[0127] The compositions of the present invention may be used in photoinitiation methods. Accordingly, in a third aspect of the present invention, a photoinitiation method is provided, comprising: (a) forming a layer of the composition of the second aspect of the present invention on a substrate; (b) applying an acid or generating an acid in situ to selected areas of the layer and reacting the acid with a compound of formula I or II to produce a reactive derivative of formula III in the selected areas of the layer; (c) exposing the layer having the reactive derivative present in the selected regions to electromagnetic radiation of a wavelength or energy suitable to generate a reactive species from the compound of Formula III; and (d) the reactive species directly or indirectly causes the conversion of a convertible substrate; A photoinitiation method is provided, including:

[0128] In some embodiments, allowing the acid to react with the compound of Formula I or II to form the reactive derivative of Formula III can include the application of heat, which can be simultaneous with the application of the acid or in situ generation of the acid, or can be subsequent to this step.

[0129] In some embodiments, the method may further include performing a pre-conversion and / or post-conversion heat treatment. In other words, step c) above, in which the layer having the reactive derivative is exposed to electromagnetic radiation, may be followed by a heat treatment to allow reaction of any acid present with the convertible substrate. Similarly, step d) above, in which the reactive species cause conversion of the convertible substrate, may be followed by a heat treatment to initiate curing of the remaining converted substrate.

[0130] The reactive species can be, for example, a free radical species or an energetically excited form of a compound of formula III.

[0131] In one embodiment, an acid can be applied to selected areas of the layer to react with the compound of Formula I or II to produce a reactive derivative of Formula III in the selected areas of the layer. The acid can be applied, for example, by spraying or inkjet printing.

[0132] In another embodiment, an acid generator is incorporated into the composition applied to the substrate. Photoacid generators (PAGs) are preferred, although thermal acid generators (TAGs) can also be used. The acid generator is a species capable of generating an acid in response to an external stimulus, thereby generating an acid in situ, which reacts with a compound of Formula I or II to form a reactive derivative of Formula III in selected areas of the layer where the acid is generated. Although currently less preferred, following formation of the layer, the acid generator can be applied to the layer by, for example, spraying or inkjet printing.

[0133] In some examples, application of an acid or in situ acid generation is followed by a heat treatment step to allow the acid to sufficiently react with the compound of Formula I or II to form the reactive derivative of Formula III in all selected regions of the layer. The heat treatment step can be carried out regardless of whether the acid is applied externally or generated by a photoacid generator or a thermal acid generator. The temperature and duration of the heat treatment can vary depending, for example, on the concentration and strength of the externally applied acid or, in the case of a photoacid generator, the intensity and duration of exposure to electromagnetic radiation.

[0134] A reactive derivative of formula III is formed in selected regions of the layer in the first step of the method. In a subsequent step, reactive species are generated from the compound of formula III by exposure to electromagnetic radiation of a suitable wavelength. If the first step is performed photochemically using a PAG, the wavelength of the electromagnetic radiation used in the subsequent step is different from that used in the first step and is selected to avoid further generation of acid from the PAG. This allows the application of electromagnetic radiation in the second step to be performed at high energy as flood radiation, which does not need to be performed in an imagewise manner.

[0135] As used herein, a direct photoinitiated reaction is a reaction in which a reactive species generated from a compound of Formula III directly causes the conversion of a convertible substrate. This can occur, for example, when the reactive species directly initiates the polymerization of a polymerizable monomer.

[0136] An indirect photoinitiated reaction is one in which a reactive species generated from a compound of Formula III indirectly induces the conversion of a reactive substrate. This can occur, for example, when a reactive species interacts with a second photoinitiator or synergist by transferring its energy or electrons to another species, which then initiates or induces the conversion of the convertible substrate. Another example of an indirect photoinitiated reaction is one in which a reactive species photosensitizes a photoacid generator to generate an acid capable of inducing the conversion of a polymerizable substrate via cationic polymerization, or one in which an acid-labile protecting group of a protected polymer can be removed to render the polymer soluble in a suitable developer. In such methods, the generation of an acid capable of inducing the conversion of a polymerizable substrate can be achieved by applying heat. In some instances, a heat treatment can also be performed after dissolving and rinsing off the solubilized polymer to cure the remaining composition.

[0137] The composition of the present invention is particularly suitable as a photoresist composition. A layer of such a composition on a substrate, which can be used in the method of the third aspect of the present invention, is called a photoresist. Another aspect of the present invention is a photoresist layer formed on a substrate from the composition of the second aspect of the present invention.

[0138] The convertible substrate can be a polymerizable substrate, such as a cationically polymerizable substrate or a free radical-accelerated polymerizable substrate, or a substrate that includes acid-labile protecting groups on a protected polymer that can be removed by acid to render the polymer soluble in a suitable developer.

[0139] The cationically polymerizable compounds may be monomers, oligomers, and / or prepolymers. These monomers, oligomers, and / or prepolymers may have different degrees of functionality. Mixtures may be used, including combinations of mono-, di-, tri-, and higher-functional monomers, oligomers, and / or prepolymers.

[0140] In a preferred embodiment, the monomer, oligomer or prepolymer comprises at least one epoxy group, at least one vinyl ether group or at least one oxetane group as polymerizable group.

[0141] Examples of monomers, oligomers or prepolymers containing at least one epoxide group include epichlorohydrin-bisphenol S based epoxides, epoxidized styrene and more epichlorohydrin-bisphenol F and A based epoxides and epoxidized novolaks, alicyclic polyepoxides, polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyols, polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl esters of aromatic polyols, polyglycidyl ethers of aromatic polyols, bis-(3,4-epoxycyclohexyl)-adipate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, poly[(2-oxiranyl)-1, 2-Cyclohexanediol]-2-ethyl-2-(hydroxymethyl)-1,3-propanediol ether, 7-oxabicyclo[4.1.0]hept-3-ylmethyl 7-oxa-bicyclo[4.1.0]heptane-3-carboxylate, and other urethane polyepoxy compounds and polyepoxy polybutadiene alicyclic epoxy compounds; 3-(bis(glycidyloxymethyl)methoxy)-1,2-propanediol, limonene oxide, 2-biphenyl glycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and other diol derivatives; n-butyl glycidyl ether, distilled butyl glycidyl ether, 2-ethylhexyl glycidyl ether, C 8-10 Aliphatic glycidyl ether, C 12-14Examples of glycidyl ethers include aliphatic glycidyl ethers, o-cresyl glycidyl ether, p-tertiary butylphenyl glycidyl ether, nonylphenyl glycidyl ether, phenyl glycidyl ether, cyclohexanedimethanol diglycidyl ether, polypropylene glycol diglycidyl ether, polyglycol diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, trimethylopropane triglycidyl ether, castor oil triglycidyl ether, propoxylated glycerin triglycidyl ether, sorbitol polyglycidyl ether, and glycidyl ester of neodecanoic acid; and glycidyl amines such as epoxidized meta-xylenediamine.

[0142] Examples of monomers, oligomers, or prepolymers containing at least one vinyl ether group include ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, butanediol divinyl ether, hydroxybutyl vinyl ether, cyclohexanedimethanol monovinyl ether, phenyl vinyl ether, p-methylphenyl vinyl ether, p-methoxyphenyl vinyl ether, a-methylphenyl vinyl ether, b-methylisobutyl vinyl ether, and b-chloroisobutyl vinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, dodecyl vinyl ether, diethylene glycol monovinyl ether, cyclohexanedimethanol divinyl ether, 4-(vinyloxy)butylbenzoate, and the like. ester, bis[4-(vinyloxy)butyl]adipate, bis[4-(vinyloxy)butyl]succinate, 4-(vinyloxymethyl)cyclohexylmethylbenzoate, bis[4-(vinyloxy)butyl]isophthalate, bis[4-(vinyloxymethyl)cyclohexylmethyl]glutarate, tris[4-(vinyloxy)butyl]trimellitate, 4-(vinyloxy)butylsteatite, bis[4-(vinyloxy)butyl]hexanediylbiscarbamate, bis[4-(vinyloxy)methyl]cyclohexyl]methyl]terephthalate, bis[4-(vinyloxy)methyl]cyclohexyl]methyl]isophthalate, bis[4-(vinyloxy)butyl](4-methyl-1,3-phenylene)-biscarbamate, bis[4-(vinyloxy)butyl](methylenedi-4,1-phenylene)biscarbamate, and 3-amino-1-propane vinyl ether.

[0143] Examples of monomers, oligomers, or prepolymers containing at least one oxetane group include 3,3'-oxybis(methylene)bis(3-ethyloxetane), 3-ethyl-3-hydroxymethyl-1-oxetane, the oligomeric mixture 1,4-bis[3-ethyl-3-oxetanylmethoxy)methyl]benzene, 3-ethyl-3-[(phenylmethoxy)methyl]-oxetane, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, and bis[1-ethyl(3-oxetanyl)]methyl ether, 3-ethyl-[(triethoxysilylpropoxy)methyl]oxetane, and 3,3-dimethyl-2(p-methoxyphenyl)-oxetane.

[0144] The free-radically polymerizable compounds may be monomers, oligomers, and / or prepolymers. These monomers, oligomers, and / or prepolymers may have different degrees of functionality. Mixtures may be used, including combinations of mono-, di-, tri-, and higher-functional monomers, oligomers, and / or prepolymers.

[0145] In another preferred embodiment, the monomer, oligomer or prepolymer comprises at least one acrylate group or at least one methacrylate group as the polymerizable group.

[0146] Suitable free radical promoted polymerizable mono- or polyfunctional monomers are: isoamyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, decyl acrylate, isoamylstyl acrylate, isostearyl acrylate, 2-ethylhexyl diglycol acrylate, 2-hydroxybutyl acrylate, 2-acryloyloxyethylhexahydrophthalic acid, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxypropylene glycol acrylate, phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, methyl ... Diethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, vinyl ether acrylate, 2-acryloyloxyethyl succinate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, lactone-modified flexible acrylate and t-butylcyclohexyl acrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-Nonanediol diacrylate, neopentyl glycol diacrylate, dimethylol-tricyclodecane diacrylate, bisphenol A EO (ethylene oxide) adduct diacrylate, bisphenol A PO (propylene oxide) adduct diacrylate, hydroxypivalate neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, alkoxylated dimethyloltricyclodecane diacrylate and polytetramethylene glycol diacrylate, trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, tri(propylene glycol) triacrylate, caprolactone-modified trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxy tetraacrylate, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, glycerin propoxy triacrylate and caprolactam-modified dipentaerythritol hexaacrylate, or N-vinylamides such as N-vinylcaprolactam or N-vinylformamide; or acrylamides or substituted acrylamides such as acryloylmorpholine.

[0147] Other suitable monofunctional acrylates include caprolactone acrylate, cyclic trimethylolpropane formal acrylate, ethoxylated nonylphenol acrylate, isodecyl acrylate, isooctyl acrylate, octyldecyl acrylate, alkoxylated phenol acrylate, tridecyl acrylate, and alkoxylated cyclohexanone dimethanol diacrylate.

[0148] Other suitable difunctional acrylates include alkoxylated cyclohexanone dimethanol diacrylate, alkoxylated hexanediol diacrylate, dioxane glycol diacrylate, cyclohexanone dimethanol diacrylate, diethylene glycol diacrylate, and neopentyl glycol diacrylate.

[0149] Other suitable trifunctional acrylates include propoxylated glycerin triacrylate and propoxylated trimethylolpropane triacrylate.

[0150] Other higher functionality acrylates include ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, ethoxylated pentaerythritol tetraacrylate, methoxylated glycol acrylates and acrylate esters.

[0151] Additionally, methacrylates corresponding to the acrylates may be used along with these acrylates.

[0152] Examples of polymerizable oligomers include epoxy acrylates, aliphatic urethane acrylates, aromatic urethane acrylates, polyester acrylates, and linear acrylic oligomers.

[0153] The use of a polymerizable substrate can form a negative-acting photoresist, in which exposed portions or regions of the photoresist become insoluble in the photoresist developer via a polymerization reaction of the convertible substrate. In the case of a cationically polymerizable substrate, after exposure to UV light, there can also be a heating step, called a post-exposure bake (PEB), to complete the polymerization reaction. The unexposed and unpolymerized portions can be dissolved and removed with a suitable photoresist developer. After the developer step, a patterned coating that is insoluble in the developer remains on the surface. Depending on the application of the photoresist as a permanent coating, such as a solder mask or dielectric layer, further steps can be performed to harden the coating, such as a curing step that can be performed by applying heat and / or additional exposure to UV light.

[0154] If heat is applied, this can be done, for example, by heating on a hot plate, or by baking in a static or conveyorized hot air circulating oven, or by using a conveyorized infrared oven. In the case of further exposure to light, this can be done, for example, by using a conveyor to pass the substrate under a lamp that emits UV light of one or more wavelengths suitable for initiating further free radical polymerization.

[0155] For temporary resists such as etch or plate resists, an additional hardening step is usually not required as it makes subsequent removal of the resist more difficult.

[0156] In another embodiment, the convertible substrate can be a protected polymer, for example, a polymer having a polar group protected by an acid labile group, and the polymer is soluble in the development medium after removal of the acid labile group. Examples of suitable polymers protected by acid labile groups are described, for example, in U.S. Pat. No. 4,491,628A, the contents of which are incorporated herein by reference, and include poly(tert-butyloxycarbonyloxy-D-alkylstyrene), poly(p-tert-butyloxycarbonyloxy-D-methylstyrene), poly(tert-butyloxycarbonyloxystyrene), poly(p-tert-butyloxycarbonyloxy-styrene), and poly(tert-butylvinylbenzoate), poly(tert-butyl methacrylate), or copolymers thereof. In such examples, the acid labile group is a tert-butyl ester of a pendant carboxylic acid group of the polymer or a tert-butyl carbonate of a pendant phenol of the polymer. Other examples of suitable polymers protected by acid labile groups are described in US Pat. No. 7,858,287 B2, US Pat. No. 9,529,259 B2 and US Pat. No. 6,136,499 A, the contents of which are incorporated herein by reference.

[0157] This embodiment allows for the formation of a positive photoresist, in which the exposed portions of the photoresist become soluble in the photoresist developer due to the deprotection of the polymer and can therefore be removed by the developer, while the unexposed portions of the photoresist remain insoluble in the photoresist developer. After the developer step, a patterned coating remains on the surface that is insoluble in the developer. Further steps, such as a curing step that can be performed by the application of heat, can be performed to harden the coating. One example of the use of positive photoresists is in high-resolution lithography.

[0158] In another embodiment, the convertible substrate can be a protected dissolution promoter, e.g., a dissolution inhibitor containing an acid labile group that generates a material that is a dissolution promoter after an acid-catalyzed hydrolysis reaction. Examples of dissolution inhibitors containing acid labile groups and their uses are found in "Introduction to Microlithography" (2002). nd This is described on pages 223-227 and figure 85 of the ISBN 0-8412-2848-5.

[0159] The composition may further contain a quencher, also known as an acid diffusion controller or its photodecomposable counterpart. Such compounds control the diffusion of acid generated in the resist film upon exposure, thereby suppressing undesired chemical reactions in unexposed areas. The acid diffusion controller may be a nitrogen-containing organic compound whose basicity is not altered by exposure or heat treatment, and is typically present in an amount of 0.005 to 5% by weight of the composition. Examples of acid diffusion controllers include amines such as secondary lower aliphatic amines and tertiary lower aliphatic amines, e.g., trimethylamine, diethylamine, di-n-propylamine, tri-n-propylamine, tripentylamine, diethanolamine, triethanolamine, quaternary ammonium compounds, trialkylammonium compounds, amides, urea, TBOC-blocked amines, and combinations thereof.

[0160] Examples of photodegradable acid diffusion control agents include aryl sulfonium or iodonium salts containing anions such as acetate, hydroxide, or sulfamate, as well as those disclosed in US Pat. No. 8,614,047 B2.

[0161] The composition may contain additional ingredients known in the art such as crosslinkers, colorants, inorganic mineral fillers, surface modifiers such as flow agents and defoamers, free radical scavengers, stabilizers, plasticizers and adhesion promoters.

[0162] Further details of photoinitiation methods in which the compounds and compositions of the present invention can be used are described in WO 2011 / 086389 A1, the contents of which are incorporated herein by reference in their entirety.

[0163] Further, the compounds and compositions are described in U.S. Patent Application Publication Nos. 2015241783A1, 2016327869A1, and 2016357103A1; "Photosensitized Chemically Amplified Resist™ (PSCAR™) 2.0 for high throughput and high resolution EUV lithography: Dual photosensitization of acid generation and quencher decomposition by flood exposure," S. Tagawa et al., Proc. of SPIE Vol. 10146, Advances in Patterning Materials and Processes XXXIV, 101460G (2017); "Super High Sensitivity Enhancement by Photo-Sensitized Chemically Amplified Resist (PS-CAR) Process," S. Tagawa et al., J. Photopolymer Science and Technology, 26(6), 825 (2013); and "High-resist sensitization by pattern and flood combination lithography," S. Nagahara et al. al., Proc. SPIE, 9048, 90481S (2014), all of which are incorporated by reference in their entirety for all purposes. The electromagnetic wave for patterning in the first stage can be, for example, EUV (13.5 nm), ArF (193 nm), KrF (248 nm), or an electron beam. The electromagnetic radiation used as flood radiation in the second stage can be a 365 nm, 375 nm, 385 nm, 395 nm, 405 nm, or 415 nm LED, or a UV lamp with a broader wavelength distribution.

[0164] Synthesis of Compounds of the Invention The compounds of the present invention of formula I can be synthesized by a variety of methods.

[0165] For example, compounds of Formula I in which one diol in the ring of the spiro[(1,3)dioxolane-2,9'-thioxanthene] structure is substituted with, for example, an alkylhydroxy group can be synthesized by first preparing the corresponding dihydroxyalkyl-substituted 9H-thioxanthen-9-one compound protected as a diacetate that can then be removed. The protected structure is then reacted with ethylene glycol to protect the carbonyl group with a 1,3-dioxolane group, or with 1,3-propylene glycol to protect the carbonyl group with a 1,3-dioxane group, or with 1,4-butanediol to protect the carbonyl group with a 1,3-dioxepane group, or with 1,5-pentanediol to protect the carbonyl group with a 1,3-dioxocane group, or with 1,6-hexanediol to protect the carbonyl group with a 1,3-dioxonane group. Other glycols can also be used to generate substituted dioxolane, dioxane, dioxepane, dioxocane, or dioxonane groups. The acetate protecting group can then be removed to generate, for example, dihydroxyalkyl-substituted spiro[(1,3)dioxolane-2,9'-thioxanthene] compounds.

[0166] The diacetate-protected compound can be reacted with Lawesson's reagent (2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-dithione) followed by reaction with a diol, such as phthalyl alcohol (benzene-1,2-dimethanol). This synthetic route is shown in the following illustrative reaction scheme:

[0167] [ka]

[0168] Hydroxyl or alkoxy substituted 9H-thioxanthen-9-one precursors can be made by the following synthetic route.

[0169] [ka]

[0170] [ka]

[0171] [ka]

[0172] An example of the synthesis of a dimeric compound is given in Scheme 5 below.

[0173] [ka]

[0174] It is within the means of one of ordinary skill in the art to modify any of the synthetic methods described above to synthesize any of the compounds within the scope of the invention not explicitly exemplified. [Example]

[0175] The invention is illustrated by the following non-limiting examples. [Example 1] Synthesis of [(1,5-dihydrospiro[benzo[e][1,3]dioxepin-3,9'-thioxanthene)-3',4'-diylbis(oxy)]bis(ethane-2,1-diyl)diacetate Step I: [(9-)oxo-9H-thioxanthene-3,4-diyl)bis(oxy)](ethane-2,1-diyl)diacetate Run 1 3,4-Dihydroxy-9H-thioxanthen-9-one (110 g, 0.45 mol) was dissolved in N,N-dimethylformamide (1500 mL) under a nitrogen atmosphere and anhydrous cesium carbonate (176 g) was added. 2-Bromoethyl acetate (165 g, 0.988 mol) was added to the solution via a dropping funnel, and the mixture was stirred for 10 minutes. The reaction was heated to 70°C (oil bath temperature) and stirred overnight. The solvent was removed on a rotary evaporator, and the residue was dissolved in saturated ammonium chloride solution (1000 mL). This was extracted with ethyl acetate (3 x 500 mL). The combined organic extracts were washed with brine (1000 mL) and then dried over sodium sulfate. The drying agent was removed by filtration, and the filtrate was concentrated to leave 192 g of a dark brown sticky solid. This was triturated with methanol (500 ml) and the light brown solid was collected by filtration, washed on the filter with methanol (100 ml) and then dried in a vacuum oven at 35° C. This gave 146 g, 0.351 mol, 78% yield.

[0176] LC / MS confirmed the structure weight of M+1=417.07, and the purity by HPLC was 96.02%. 1H NMR was consistent with the desired structure.

[0177] Run 2+3 3,4-Dihydroxy-9H-thioxanthen-9-one (331 g, 1.355 mol) was dissolved in N,N-dimethylformamide (4600 ml) under a nitrogen atmosphere, and anhydrous cesium carbonate (532 g, 1.633 ml) was added. 2-Bromoethyl acetate (500 g, 2.994 mol) was added to the solution via a dropping funnel, and the mixture was stirred for 10 minutes. The reaction was heated to 70 °C (oil bath temperature) and stirred overnight. The solvent was removed on a rotary evaporator, and the two reactions were combined at this stage. The residue was dissolved in saturated ammonium chloride solution (3000 ml). This was extracted with ethyl acetate (4 x 2000 ml). The combined organic extracts were washed with water (3000 ml), forming an emulsion. This was filtered through GF / F to remove some solid material. The combined organic extracts were washed with brine (3000 ml) and then dried over sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated to leave 358 g of a dark brown sticky solid. This was triturated with methanol (1000 ml) and the light brown solid was collected by filtration, washed on the filter with methanol (100 ml), and then dried in a vacuum oven at 35° C. This gave 199.5 g, a 41.5% yield.

[0178] LC / MS confirmed the structure weight of M+1=417.18, and the purity by HPLC was 94.19%.

[0179] The solids previously removed by filtration were slurried in dichloromethane (5000 ml) at room temperature for 2 hours. This was then filtered through GF / F. The aqueous extract was re-extracted with dichloromethane (5000 ml), separated, and combined with the dichloromethane filtrate. The organic extract was stirred over sodium sulfate for 1 hour and then filtered. The filtrate was concentrated to a brown oil, which was triturated with methanol (750 ml) for 1 hour, and the solid was then collected by filtration. This was washed on the filter, leaving a light tan solid. This was dried to give 152 g, with a purity of 99.05% by HPLC. This gave a total yield of 351.5 g, 62.3%.

[0180] Run 4 3,4-Dihydroxy-9H-thioxanthen-9-one (130 g, 0.565 mol) was dissolved in N,N-dimethylformamide (1900 ml) under a nitrogen atmosphere, and anhydrous cesium carbonate (221 g, 0.678 ml) was added. 2-Bromoethyl acetate (209 g, 1.25 mol) was added to the solution via a dropping funnel, and the mixture was stirred for 10 minutes. The reaction was heated to 70°C (oil bath temperature) and stirred overnight. The solvent was removed on a rotary evaporator. The residue was dissolved in ethyl acetate (700 ml) and then added to saturated ammonium chloride solution (1400 ml). This was extracted with ethyl acetate (2 x 700 ml). The combined organic extracts were washed with water (3000 ml), resulting in the formation of an emulsion. This was filtered through GF / F to remove some solid material. The combined organic extracts were washed with brine (1400 ml) and then dried over sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated to leave a dark brown sticky solid. This was triturated with methanol (700 ml) and the light brown solid was collected by filtration, washed on the filter with methanol (3 x 100 ml), and then dried in a vacuum oven at 35°C. This gave 171 g, a 72.7% yield.

[0181] LC / MS confirmed the structure weight of M+1=417.25, and the purity by HPLC was 93.74%.

[0182] Step II: [(9-)Thioxo-9H-thioxanthene-3,4-diylbis(oxy)](ethane-2,1-diyl)diacetate Run 1 [(9-oxo-9H-thioxanthene-3,4-diyl)bis(oxy)](ethane-2,1-diyl) diacetate (145 g, 0.351 mol) and Lawesson's reagent (85 g, 0.211 mol) were suspended in toluene (1500 ml) under a nitrogen atmosphere. The light brown suspension was heated at 85°C for 3 hours, after which a dark green solution formed, and TLC (1:1 hexane / ethyl acetate) indicated the reaction was complete. The reaction was cooled to room temperature and then poured into saturated sodium bicarbonate solution (2.2 lt). The two layers were separated, and the aqueous phase was extracted with ethyl acetate (3 x 750 ml). The combined organic extracts were washed with brine (1000 ml), dried over sodium sulfate, and then filtered through GF / F. The filtrate was concentrated to a dark green sticky solid, which was triturated with methanol (600 ml) and allowed to stand for 2 hours. The solid was collected by filtration and washed on the filter with methanol until the brown color disappeared. The dark green solid was air-dried to give 137 g, 90.3%, with an HPLC purity of 89.45% (5.4% early peak, likely a ketone, an HPLC artifact). Mass spectrometry confirmed the molecular weight as M+1 = 433.16.

[0183] Run 2 [(9-oxo-9H-thioxanthene-3,4-diyl)bis(oxy)](ethane-2,1-diyl) diacetate (249 g, 0.598 mol) and Lawesson's reagent (146 g, 0.361 mol) were suspended in toluene (2600 ml) under a nitrogen atmosphere. The light brown suspension was heated at 85°C for 2 hours, after which a dark green solution formed, and TLC (1:1 hexane / ethyl acetate) indicated the reaction was complete. The reaction was cooled to room temperature and then poured into saturated sodium bicarbonate solution (6 ltr). The two layers were separated, and the aqueous phase was extracted with ethyl acetate (3 x 1500 ml). The combined organic extracts were washed with brine (2000 ml), dried over sodium sulfate, and then filtered through GF / F. The filtrate was concentrated to a dark green sticky solid, which was triturated with methanol (1000 ml) and allowed to stand for 24 hours. The solid was collected by filtration and washed on the filter with methanol until the brown color disappeared. The dark green solid was air-dried to give 230 g, 88.9%, with an HPLC purity of 90.74% (4.79% early peak, likely a ketone, an HPLC artifact). Mass spectrometry confirmed the molecular weight as M+1 = 433.24.

[0184] Step III: Benzene-1,2-dimethanol Phthalic acid (450 g, 2.71 mol) was slurried in tetrahydrofuran (4000 ml) under nitrogen and cooled to 0-5°C. Borane / tetrahydrofuran complex in tetrahydrofuran (7020 ml, 7.02 mol) was added, followed by stirring and warming to room temperature overnight. The reaction was judged complete by TLC (toluene / ethyl acetate / formic acid, 5:4:1). The reaction was quenched by dropwise addition of a 1:1 mixture of water and tetrahydrofuran (1630 ml), and the aqueous layer was then saturated with potassium carbonate (800 g). The mixture was stirred for 30 minutes and then separated. The aqueous phase was extracted with tetrahydrofuran (3 x 1600 ml), and the combined organic extracts were stirred over sodium sulfate for 1 hour. The drying agent was removed by filtration, and the filtrate was concentrated to give 366 g of a white crystalline solid, which turned yellow overnight. The solid was slurried in hexane (1000 ml) for 1 hour, then filtered and washed on the filter with hexane (500 ml). The solid was sucked dry for 30 minutes and then air-dried. This gave a white crystalline solid, 333 g, 88.9%, with a purity of 94.4% by GC. The structure was confirmed by NMR.

[0185] Mass spectrometry showed no molecular ion but showed a dehydration fragment M+1=121 and loss of the CH2 fragment as the major peak at M+1=93.

[0186] Stage IIIa: [(1,5-dihydrospiro[benzo[e][1,3]dioxepin-3,9'-thioxanthene]-3',4'-diylbis(oxy)]bis(ethane-2,1-diyl)diacetate [(9-)Thioxo-9H-thioxanthene-3,4-diyl)bis(oxy)](ethane-2,1-diyl)diacetate (135 g, 0.312 mol) was suspended in acetonitrile (2700 mL) under a nitrogen atmosphere. To this was added benzene-1,2-dimethanol (65 g, 0.47 mol) and triethylamine (180 mL). The reaction mixture was warmed to 30°C (oil bath temperature), and then a solution of copper trifluoroacetate (227.3 g, 0.785 mol) in acetonitrile (1000 mL) was added over several hours. The reaction was then warmed to 35°C (oil bath temperature) for 3 days. TLC (4:1 hexane / ethyl acetate) indicated the reaction was complete.

[0187] The solvent was removed on a rotary evaporator, leaving a black residue. This was partitioned between brine (2000 mL) and ethyl acetate (2000 mL) and then filtered through Celite on GF / F to remove copper salts. The filter cake was washed with ethyl acetate (1000 mL). The filtrate was separated, and the aqueous layer was extracted with ethyl acetate (500 mL). The combined organic extracts were dried over sodium sulfate, filtered, and concentrated to give a dark brown oil (238 g). This was dispersed in isopropyl alcohol (3500 mL) under a nitrogen atmosphere. Sodium borohydride (83 g, 2.19 mol) was added, and the mixture was then heated at 65°C (oil bath temperature) for 3 hours. TLC (1:1 hexane / ethyl acetate) indicated complete reduction of the ketone.

[0188] The reaction mixture was cooled to room temperature and then poured into water (10 ltr) and stirred. The product was extracted with dichloromethane (3 x 1500 ml), and the combined organic extracts were washed with brine (2000 ml) and dried over sodium sulfate. The drying agent was removed by filtration through GF / F, and the filtrate was concentrated to leave 156 g of a viscous brown oil, which crystallized overnight. This was dissolved in hexane / ethyl acetate (2:1) (250 ml) and passed through a basic (Brockmann grade I) alumina column (1200 g) to concentrate the diacetate-containing fractions, which were then triturated with methanol. The solid was collected and dried, leaving 2 g of DAS-22-74-1. NMR was consistent with the structure.

[0189] The column was then flushed with methanol to collect the next product, and the fractions were concentrated to a dark orange oil, which crystallized overnight. This was triturated with methanol containing approximately 10% t-butyl methyl ether. The solid was collected, washed with methanol and t-butyl methyl ether, and then dried overnight in a vacuum oven at 35°C. This yielded 29 g of an off-white solid, which was confirmed to be the diol by 1H NMR (hydrolyzed during aqueous workup).

[0190] It has been found that the compounds of the present invention are deprotected and deblocked in the presence of acid to reveal thioxanthone photoinitiators, thus making the compounds useful in the compositions and methods described herein.

[0191] Although the compounds, methods and related embodiments have been described with reference to particular examples, it will be understood that various modifications, changes, omissions and substitutions can be made without departing from the spirit of the disclosure. Features of any dependent claim may be combined with features of any other dependent claim or with any and / or any of the independent claims.

Claims

1. Compounds of Formula I: 【Chemistry 1】 During the ceremony, n = 0 or 1; m = 0, 1, 2 or 3; R １ and R ２ is hydroxy C １－６ Alkyl group or its carboxylate ester, C １－６ Alkylthio group, C １－６ Alkylamino group, ester portion is C １－６ C containing alkyl groups and / or 4- to 10-membered carbocyclic groups １－６ carboxylate ester groups; and R ３ , R ４ , R ５ , R ６ , R ７ and R ８ is H, a hydroxy group, C １－６ Alkyl group, C ２－６ Alkenyl group, C １－６ Alkoxy group, C １－６ Alkylthio group, 4- to 8-membered carbocyclic group, 4- to 8-membered heterocyclic group, ester moiety is C １－６ C containing alkyl groups and / or 4- to 10-membered carbocyclic groups １－６ carboxylate ester groups; or R ５ is R ３ Or R ７ and together with the carbon atom to which they are attached form a 4- to 8-membered carbocyclic or 4- to 8-membered heterocyclic group.

2. Compound of Formula II: 【Chemistry 2】 During the ceremony, m=0, 1, 2, 3 or 4; and One of the aromatic rings is hydroxy C （１－６） Alkyloxy group (—O—C （１－６） alkyl-OH) or its carboxylate ester, —O—C （１－６） Alkylthio group, —O—C （１－６） Alkylamino group, ester portion is C １－６ -O-C containing alkyl groups and / or 4- to 10-membered carbocyclic groups （１－６） disubstituted at the 3- and 4-positions with substituents independently selected from carboxylate ester groups; or One or both of the aromatic rings may be hydroxy, alkoxy, benzyloxy, C １－６ Alkyl carbonate, hydroxyalkyl, C １－４ Alkoxyalkyl, cyclic acetal, C １－４ substituted with at least one substituent independently selected from alkyl acid esters, cyclic orthoesters, oxyacetic acid and its esters, aryloxy, and arylthio; and L=a linker group, where the linker group is a C 1-6 alkyl group or a C 2-6 alkenyl group, each of which may be substituted.

3. One of the aromatic rings is hydroxy, alkoxy, benzyloxy, C １－６ Alkyl carbonate, hydroxyalkyl, C １－４ Alkoxyalkyl, cyclic acetal, C １－４ 3. The compound of claim 2, substituted with 1, 2, 3, or 4 substituents independently selected from alkyl acid esters, cyclic orthoesters, oxyacetic acids and their esters, aryloxy, and arylthio.

4. 4. The compound of claim 2 or 3, wherein one of the aromatic rings is substituted with two identical substituents.

5. The aromatic rings are each selected from hydroxy, alkoxy, benzyloxy, C １－６ Alkyl carbonate, hydroxyalkyl, C １－４ Alkoxyalkyl, cyclic acetal, C １－４ 3. The compound of claim 2, substituted with 1, 2, 3, or 4 substituents independently selected from alkyl acid esters, cyclic orthoesters, oxyacetic acids and their esters, aryloxy, and arylthio.

6. The compound of claim 5 , wherein each of the aromatic rings is substituted with a single substituent.

7. 6. The compound of claim 5, wherein one of the aromatic rings is substituted with two substituents and the other of the aromatic rings is substituted with one, two, three, or four substituents.

8. 6. The compound of claim 5, wherein one of the aromatic rings is substituted with three substituents and the other of the aromatic rings is substituted with one, two, three, or four substituents.

9. 6. The compound of claim 5, wherein one of the aromatic rings is substituted with four substituents and the other of the aromatic rings is substituted with one, two, three, or four substituents.

10. R ５ is R ３ or R ７ and together with the carbon atom to which they are attached form a six-membered carbocyclic group.

11. C １－６ The compound of any one of claims 1 to 10, wherein the alkoxy is methoxy.

12. Hydroxy C １－６ The compound of any one of claims 1 to 11, wherein the alkyl is 2-hydroxyisopropyl.

13. R １ and R ２ are independently hydroxy C １－６ 10. The compound of claim 1 which is an alkyl group or a carboxylate ester thereof.

14. C １－６ The compound according to any one of claims 2 to 9, wherein the alkyl carbonate is t-butyl carbonate.

15. C １－４ 10. The compound of any one of claims 2 to 9, wherein the alkyl acid ester is an acetate ester or the cyclic orthoester is a methyl orthoformate ester, an ethyl orthoformate ester, an n-propyl orthoformate ester, or an isopropyl orthoformate ester.

16. C １－４ The compound of any one of claims 2 to 9, wherein the alkoxyalkyl group is ethoxyethyl.

17. The compound of any one of claims 2 to 9, wherein the substituents on the aromatic ring are selected from hydroxy and alkoxy.

18. The compound of any one of claims 1 to 17, wherein all of the substituents on the aromatic ring are the same.

19. 19. The compound of any one of claims 1 to 18, wherein n and / or m are selected to form a 5-, 6- or 7-membered cyclic ketal.

20. The compound is (i) 2,3-dimethoxy-9H-thioxanthen-9-one, 2,3-dihydroxy-9H-thioxanthen-9-one, 2,3,5-trimethoxy-9H-thioxanthen-9-one, 2,3,7-trimethoxy-9H-thioxanthen-9-one, 1,5,6-trihydroxy-9H-thioxanthen-9-one, 1,5,6-trimethoxy-9H-thioxanthen-9 -one, 3,4-dihydroxy-9H-thioxanthen-9-one, 3,4-dimethoxy-9H-thioxanthen-9-one, 3,4-bis(benzyloxy)-9H-thioxanthen-9-one, 3,4-bis(1-ethoxyethyl)-9H-thioxanthen-9-one, di-t-butyl(9-thioxo-9H-thioxanthen-3,4-diyl)dicarbonate, 2-methan- Oxythiochromeno[3,2-g][1,3]benzodioxol-6-one, 2-ethoxythiochromeno[2,3-e][1,3]benzodioxol-6-one, 2-[4-(2-acetoxyethoxy)-9-oxo-thioxanthen-3-yl]oxyethyl acetate, 3,4-bis(2-hydroxyethoxy)thioxanthen-9-one, (1-ethylcyclopentyl ) 2-[4-[2-(1-ethylcyclopentoxy)-2-oxo-ethoxy]-9-oxo-thioxanthen-3-yl]oxyacetate, and (2-methyl-2-adamantyl) 2-[4-[2-[(2-methyl-2-adamantyl)oxy]-2-oxoethoxy]-9-oxo-thioxanthen-3-yl]oxyacetate or (ii) 3',4'-dimethoxyspiro[1,3-dioxane-2,9'-thioxanthene], 3',4'-dimethoxyspiro[1,3-dioxolane-2,9'-thioxanthene], 2',3'-dimethoxyspiro[(1.3)-dioxolane-2,9'-thioxanthene], 2'-methoxyspiro[1,3-dioxane-2,6'-thiochromeno[3,2-g][1,3]benzodioxole], 2'-methoxyspiro[1,3-dioxepane-2,6'-thiochromeno[2,3-g][1,3]benzodioxole], 2'-ethoxyspiro[ 1,3-dioxepane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], 2'-propoxyspiro[1,3-dioxepane-2,6'-thiochromeno[3,2-g][1,3]benzodioxole], 2'-phenoxyspiro[1,3-dioxepane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], 2'-isopropoxyspiro[1,3-dioxepane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], 2'-ethoxyspiro[1,3-dioxane-2,6'-thio 2'-ethoxyspiro[1,3-dioxolane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], 2'-propoxyspiro[1,3-dioxane-2,6'-thiochromeno[3,2-g][1,3]benzodioxole], 2'-propoxyspiro[1,3-dioxolane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], 2'-isopropoxyspiro[1,3-dioxane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole] oxol], 2'-isopropoxyspiro[1,3-dioxolane-2,6'-thiochromeno[3,2-g][1,3]benzodioxole], 2'-methoxyspiro[1,3-dioxane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], 2'-methoxyspiro[1,3-dioxolane-2,6'-thiochromeno[2,3-e][1,3]benzodioxole], spiro[1,3-dioxolane-2,9'-thioxanthene]-3',4'-diol, spiro[1,3-dioxane-2,9'-thioxanthene]-3',4'-diol, and spiro[1,3-dioxepane-2,9'-thioxanthene]-3',4'-diol, The compound of claim 2.

21. A compound comprising: 2-[4'-(2-acetoxyethoxy)spiro[1,5-dihydro-2,4-benzodioxepin-3,9'-thioxanthen]-3'-yl]oxyethyl acetate, 2-[4'-(2-hydroxyethoxy)spiro[1,5-dihydro-2,4-benzodioxepin-3,9'-thioxanthen]-3'-yl]oxyethanol, 2-[4'-(2-acetoxyethoxy)-5-phenyl-spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyethyl acetate, 2-[4'-(2-hydroxyethoxy)-5-phenyl-spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyethanol, 2-[4'-(2-acetoxyethoxy)-5,5-dimethyl-spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyethyl acetate, 2-[4'-(2-hydroxyethoxy)-5,5-dimethyl-spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyethanol, 2-[4'-(2-acetoxyethoxy)spiro[1,3-dioxepane-2,9'-thioxanthene]-3'-yl]oxyethyl acetate, 2-[4'-(2-hydroxyethoxy)spiro[1,3-dioxepane-2,9'-thioxanthene]-3'-yl]oxyethanol, 2-[4'-(2-acetoxyethoxy)spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyethyl acetate, 2-[4'-(2-hydroxyethoxy)spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyethanol, 2-[4'-(2-acetoxyethoxy)-5-[2-[3',4'-bis(2-acetoxyethoxy)spiro[1,3-dioxane-2,9'-thioxanthene]-5-yl]ethyl]spiro[1,3-dioxane-2,9'-thioxanthene]-3'-yl]oxyethyl acetate, 2-[5-[2-[3',4'-bis(2-hydroxyethoxy)spiro[1,3-dioxane-2,9'-thioxanthene]-5-yl]ethyl]-4'-(2-hydroxyethoxy)spiro[1,3-dioxane-2,9'-thioxanthene]-3'-yl]oxyethanol, 5-[2-(3',4'-dimethoxyspiro[1,3-dioxane-2,9'-thioxanthene]-5-yl)ethyl]-3',4'-dimethoxy-spiro[1,3-dioxane-2,9'-thioxanthene], (1-ethylcyclopentyl) 2-[4'-[2-(1-ethylcyclopentoxy)-2-oxoethoxy]spiro[1,3-dioxolane-2,9'-thioxanthene]-3'-yl]oxyacetate, (2-methyl-2-adamantyl)2-[4'-[2-[(2-methyl-2-adamantyl)oxy]-2-oxoethoxy]spiro[1,3-dioxolane-2,9'-thioxanthene]-3'-yl]oxyacetate, (2-methyl-2-adamantyl)2-[4'-[2-[(2-methyl-2-adamantyl)oxy]-2-oxoethoxy]spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyacetate, and (2-methyl-2-adamantyl)2-[4,6-dimethyl-4'-[2-[(2-methyl-2-adamantyl)oxy]-2-oxoethoxy]spiro[1,3-dioxane-2,9'-thioxanthen]-3'-yl]oxyacetate A compound selected from:

22. 1. A composition comprising: (a) a compound of formula (I) or (II) as defined in any one of claims 1 to 21; and (b) a chemically convertible substrate; wherein the compound of formula (I) or (II) is a precursor of a reactive derivative of formula (III): 【Transformation 3】 During the ceremony, One of the aromatic rings is a hydroxy C （１－６） Alkyloxy group (—O—C （１－６） alkyl-OH) or its carboxylate ester, —O—C （１－６） Alkylthio group, —O—C （１－６） The alkylamino group and the ester moiety are C １－６ -O-C containing alkyl groups and / or 4- to 10-membered carbocyclic groups （１－６） disubstituted at the 3- and 4-positions with substituents independently selected from carboxylate ester groups; or One or both of the aromatic rings may be hydroxy, alkoxy, benzyloxy, C １－６ Alkyl carbonate, hydroxyalkyl, C １－４ Alkoxyalkyl, cyclic acetal, C １－４ substituted with at least one substituent independently selected from alkyl acid esters, cyclic orthoesters, oxyacetic acid and its esters, aryloxy, and arylthio; The compound of formula (III) can be obtained by reacting the compound of formula (I) or formula (II) in the presence of an acid; Further, the composition, wherein said convertible substrate can be converted by direct or indirect photoinitiation in the presence of said compound of formula (III).

23. C １－６ 23. The composition of claim 22, wherein the alkoxy is methoxy.

24. Hydroxy C １－６ 23. The composition of claim 22, wherein the alkyloxy is 2-hydroxyisopropyloxy.

25. The composition according to any one of claims 22 to 24, wherein the convertible substrate is a polymerizable substrate.

26. 26. The composition of claim 25, wherein the polymerizable substrate is a cationically polymerizable substrate or a free radical promoted polymerizable substrate.

27. The composition of any one of claims 22 to 26, wherein the convertible substrate is a protected polymer.

28. 28. The composition of claim 27, wherein the protected polymer is a polymer having polar groups protected by acid labile groups, the polymer being soluble in the development medium after removal of the acid labile groups.

29. The composition of any one of claims 22 to 28, further comprising a photoacid generator (PAG).

30. 30. The composition of claim 29, wherein the PAG is capable of being photosensitized by the compound of formula (III).

31. The composition of any one of claims 22 to 30, further comprising a quencher or a photodegradable version thereof.

32. 1. A photoinitiation method comprising: (a) forming a layer of the composition of any one of claims 22 to 31 on a support; (b) applying an acid or generating an acid in situ to selected areas of said layer and reacting said acid with said compound of formula (I) or formula (II) to form said reactive derivative of formula (III) in said selected areas of said layer; (c) exposing the layer with the reactive derivative present in the selected regions to electromagnetic radiation of a wavelength or energy suitable to generate a reactive species from the compound of formula (III); and (d) allowing said reactive species to directly or indirectly cause conversion of said convertible substrate.

33. 33. The method of claim 32, wherein the composition comprises a PAG, and in (b), an acid is generated in situ by exposing the layer to an external stimulus that causes the PAG to generate an acid in the region of the layer for reaction with the compound of Formula (I) or Formula (II).

34. 33. The method of claim 32, wherein the generated reactive species are free radicals and the convertible substrate is a free radical-promoted polymerizable substrate, whereby the free radical reactive species directly causes conversion of the convertible substrate.

35. 33. The method of claim 32, wherein the composition further comprises a coinitiator or synergist, and the generated reactive species is an excited state of the compound of formula (III) that can function as a sensitizer to activate the coinitiator or synergist.

36. 33. The method of claim 32, wherein the convertible substrate is a protected polymer having a polar group protected by an acid labile group, and the generated reactive species is an excited state of the compound of formula (III) that can function as a sensitizer to activate the PAG, thereby generating additional acid effective to convert the convertible substrate by deprotecting the protected polymer.

37. A photoresist structure comprising a substrate and a layer of the composition of any one of claims 22 to 31 formed thereon.

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