Composition comprising 2,4,6-TRIS(1,1'-biphenyl-4-YL)-1,3,5-triazine with lower amounts of impurities

Abstract

The present invention relates to a specific process for the production of 1,3,5-triazine,2,4,6-tris[1,1'- biphenyl]-4-yl (TBPT), wherein (heavy) metal impurities are reduced in the resulting product. Furthermore, the invention relates to TBPT obtained by this specific process, to cosmetic products comprising the obtained TBPT and to uses of the obtained TBPT as a UV filter in a cosmetic product for protecting hair and / or skin of a subject from the damaging effects of UV radiation.

Description

[0001] COMPOSITION COMPRISING 1,3,5-TRIAZINE, 2,4,6-TRIS[1,T-BIPHENYL]-4-YL WITH LOWER AMOUNTS OF IMPURITIES

[0002] Technical field

[0003] The present invention relates to a specific process for the production of 1 ,3,5-triazine,2,4,6-tris[1 , 1 biphenyl]-4-yl (TBPT), wherein (heavy) metal impurities are reduced in the resulting product. Furthermore, the invention relates to TBPT obtained by this specific process, to cosmetic products comprising the obtained TBPT and to uses of the obtained TBPT as a UV filter in a topical product, such as a cosmetic product for protecting hair and / or skin of a subject from the damaging effects of UV radiation.

[0004] Background

[0005] In orderto comply with Cosmetics Regulations, purity standards are set for chemical ingredients of cosmetic products. Purity standards may have particular relevance for cosmetic products comprising chemical ingredients that may exhibit impurities, which may be unbeneficial for the health of the user. In particular, aromatic hydrocarbon impurities may cause side effects on the human or animal body, when present in a cosmetic product. To reduce undesired side effects from impurities, chemical ingredients of cosmetic should be produced in a manner that focuses on reducing said impurities.

[0006] A chemical ingredient that is widely used in cosmetic products is 1 ,3,5-triazine, 2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT). Commonly, TBPT is used as a highly efficient, photostable filter against UVB and UVA II radiation in cosmetic products for protecting hair or skin of a human or animal from the damaging effects of UV radiation, such as anti-aging face care products or sun protection products. Besides, TBPT is known from electroluminescent devices (e.g., US 6,225,467 B1 , WO 2020 / 226300, WO 2020 / 231197).

[0007] In US 2004 / 0191191 A1 , a synthetic procedure is described to obtain TBPT from cyanuric chloride and 1 ,1 '-biphenyl in an aluminum chloride catalyzed reaction (Friedel-Crafts-reaction) in 1 ,2-dichlorobenzene. Without adequate purification steps, there is a risk that residual starting material may remain in the final product and thus end up in a cosmetic product. Additionally, corrosive conditions may lead to (heavy) metal contaminations in the product.

[0008] In orderto avoid impurities that may occur during TBPT synthesis in e.g. cosmetic products, there is a need of reducing those already during synthesis or purification steps.

[0009] Hence, it has been an object of the present invention to provide an optimized process for synthesizing, isolating and purifying TBPT, in particular to achieve a high-purity TBPT product with reduced (heavy) metal contaminations and, optionally, reduced organic side products, wherein the produced TBPT is preferably suitable for cosmetic application. Summary of the invention

[0010] Surprisingly, the inventors found that the production and purification process of TBPT can be improved by adding the steps of (1) pH adjustment during product isolation and / or (2) further purification with activated carbon. The newly developed processes resulted in TBPT with lower levels of metal contaminations. These results were particularly surprising because the presence of (heavy) metal contaminants in TBPT preparations and their reduction or removal have not been addressed to date.

[0011] In a first aspect, the invention therefore provides a process forthe production of 1 ,3,5-triazine,2,4,6-tris[1 , 1 biphenyl]-4-yl (TBPT), said process comprising the steps of

[0012] a) reacting a 2,4,6-trihalogen-1 ,3,5-triazine with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;

[0013] b) removing the organic solvent after the reaction is completed, preferably by distillation;

[0014] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;

[0015] d) separating, optionally washing and drying, the organic phase obtained in step c);

[0016] e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0017] f) crystallizing the TBPT from the solution obtained in step e) by cooling;

[0018] g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent and drying,

[0019] wherein the process further comprises the step(s) of:

[0020] d1) adjusting the pH of the organic phase obtained in step d) to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, optionally prior to drying, by addition of a suitable base, preferably sodium hydroxide; and / or

[0021] h) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT, and isolating the obtained TBPT, optionally washing the TBPT with a suitable organic solvent, and optionally drying the obtained TBPT.

[0022] In various embodiments, the process comprises step d1) but not step h). In various other embodiments, the process comprises step h) but not d1). In still further embodiments, the process comprises both, steps d1) and h).

[0023] In various embodiments of the process, in step a)

[0024] (1) 2, 4, 6-trihalogen-1 ,3,5-triazine is 2,4,6-trichloro-1 ,3,5-triazin (cyanuric chloride); and / or

[0025] (2) the suitable organic solvent is a non-polar solvent, preferably a linear, branched, or cyclic aliphatic hydrocarbon or aromatic hydrocarbon comprising C1-C20 carbon atoms, optionally substituted with, e.g., an C1-C3 alkyl group, alkyl-aryl ether, or alkyl-alkyl ether, optionally substituted with an alkoxy, halide or carbonyl moiety, more preferably a linear aliphatic hydrocarbon comprising C1-C20 carbon atoms, more preferably hexane or heptane, most preferably heptane. In various embodiments, in step a)

[0026] (1) the catalyst is selected from the group consisting of Lewis acids, acidic halides, metal alkyl and alkoxides, proton acids, acidic oxides, cation exchange resins and mixtures thereof, preferably selected from the group consisting of AICH, AIBrs, BF3, BCH, BBrs, BeCL, CdCL, ZnCL, GaCH, GaBrs, FeCH, SbCH, BiCH, TiCh, ZrCh, SnCh, UCh, SbCk, and mixtures thereof, more preferably AlCh; and / or

[0027] (2) the elevated temperature is equal to or higher than 90 °C, preferably equal to or higher than 100 °C, more preferably between 100 °C and 120 °C, for example 105 °C to 110 °C.

[0028] In various embodiments, the suitable organic solvent of step(s) c), g), and / or h) is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably it is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably it is selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene.

[0029] In various embodiments:

[0030] (1) the distillation step of step b) is carried out under vacuum (>100 mbar); and / or

[0031] (2) the hydrolyzing step of step c) comprises the addition of water, sodium hydroxide and an organic solvent, wherein the organic solvent is preferably as described above, wherein the hydrolyzing step is preferably carried out at a temperature of from 80 °C to 100 °C, more preferably of from about 85 °C to about 90 °C; and / or

[0032] (3) in step d), the organic phase is washed with water at 80 °C to 100 °C, preferably about 90 °C; and / or

[0033] (4) the drying in step d) comprises distillation, preferably azeotropic distillation under vacuum.

[0034] In various embodiments,

[0035] (1) the heating of step e) is to temperatures of from 130 °C to 160 °C, preferably 140 °C to 155 °C, more preferably about 143 °C to about 150 °C; and / or

[0036] (2) the crystallization of step f) comprises cooling to 30 °C to 50 °C, preferably about 40 °C.

[0037] In various embodiments, in step(s) g) and / or h), the drying is carried out under vacuum, optionally at 90°C to 110 °C, preferably at about 100 °C.

[0038] In preferred embodiments, if the process comprises step h),

[0039] (1) the activated carbon is a mixture of activated carbon and bentonite; and / or

[0040] (2) the suitable organic solvent is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably it is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably it is selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene; and / or

[0041] (3) the elevated temperature is from 130 °C to 160 °C, preferably 140 °C to 155 °C, more preferably about 150 °C; and / or

[0042] (4) removing of the activated carbon is carried out by filtration, optionally in the presence of cellulose, preferably at 130 °C to 160 °C, more preferably at 140 °C to 155 °C, most preferably at about 150 °C; and / or

[0043] (5) crystallization comprises cooling to 30 °C to 50 °C, preferably about 40 °C; and / or

[0044] (6) isolation comprises filtration and / or drying is carried out under vacuum, preferably at 90 °C to 140 °C, more preferably at 90 °C to 110 °C, more preferably about 100 °C.

[0045] In various preferred embodiments, the process according to the invention comprises the steps of

[0046] a) reacting 2,4,6-trichloro-1 ,3,5-triazin (cyanuric chloride) with biphenyl in a suitable organic solvent, preferably heptane, at elevated temperature, preferably 100 °C to 120 °C, in the presence of a catalyst, preferably AlCh;

[0047] b) removing the organic solvent after the reaction is completed, preferably by distillation under vacuum (such as at >100 mbar);

[0048] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water, sodium hydroxide and a suitable organic solvent, preferably xylene, preferably at a temperature of 80 °C to 100 °C; d) separating, washing, preferably with water, and drying the organic phase obtained in step c), preferably at a temperature of 80 °C to 100 °C, more preferably by distillation under vacuum; e) heating the organic phase obtained in step d), preferably to a temperature of 130 °C to 160 °C, to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0049] f) crystallizing the TBPT from the solution obtained in step e) by cooling, preferably to 30 °C to 50 °C;

[0050] g) isolating the crystallized TBPT obtained in step f), preferably by filtration, followed by washing with a suitable organic solvent, preferably xylene, and drying, preferably under vacuum, more preferably at 90 °C to 110 °C,

[0051] wherein the process further comprises the step(s) of:

[0052] d1) adjusting the pH of the organic phase obtained in step d) prior to drying to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, by addition of a suitable base, preferably sodium hydroxide; and / or

[0053] h) dissolving the TBPT obtained in step g) in a suitable organic solvent, preferably xylene, at elevated temperature, preferably 130 °C to 160 °C, in the presence of activated carbon and optionally bentonite, removing the activated carbon and the optional bentonite, preferably by filtration, more preferably at 130 °C to 160 °C, crystallizing the TBPT, optionally from the obtained filtrate, preferably by cooling to 30 °C to 50 °C, isolating the obtained TBPT, preferably by filtration, washing the TBPT with a suitable organic solvent, preferably xylene, and drying the obtained TBPT, preferably under vacuum, preferably at 90 °C to 110 °C. Again, in various embodiments, the process comprises step d1) but not step h). In various other embodiments, the process comprises step h) but not d1). In still further embodiments, the process comprises both, steps d1) and h).

[0054] In various embodiments, 1 ,3,5-triazine, 2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT), obtained from the process according to the invention is further purified, wherein the further purification process, performed after steps a) to g) and optionally H) given above, comprises:

[0055] A) providing the obtained TBPT product according to the invention, wherein said TBPT may comprise at least a first impurity consisting of one or more halogen-comprising triazine, and a second impurity consisting of biphenyl;

[0056] B) suspending TBPT in a solvent (S1), preferably isopropyl palmitate, thereby providing a first suspension;

[0057] C) heating the first suspension to a temperature of more than 200 °C, preferably more than 210 °C, more preferably about 220 °C, preferably under vacuum, thereby providing a heated first suspension or a first solution of TBPT in the solvent (S1);

[0058] D) keeping the heated first suspension or first solution of TBPT at a temperature between 100 °C and 235 °C, preferably 150 °C to 230 °C, more preferably 200 °C to 230 °C, most preferably about 223 °C, and a pressure of from 5 mbar to standard pressure, preferably from 5 or 10 mbar to 900 mbar or to standard pressure;

[0059] E) cooling the heated first suspension or the first solution to a temperature of 40 °C to 90 °C, preferably 50 °C to 80 °C, more preferably about 70 °C, to allow crystallization; and F) isolating the crystals from the solution to obtain a purified TBPT product, preferably by filtration, washing, preferably with isopropanol, and drying.

[0060] In various embodiments of said additional purification process,

[0061] (1) the halogen-comprising triazine is selected from chlorine-comprising triazines, brominecomprising triazines, and a mixture thereof, preferably it is 1 ,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1 ,3,5-triazine, 2,4-bis([1,1'-biphenyl]-4-yl)-6-chloro (BBCT), and most preferably it is 1,3,5- triazine, 2,4-bis([1 ,1'-biphenyl]-4-yl)-6-chloro (BBCT); and / or

[0062] (2) the obtained TBPT further comprises a third impurity, the third impurity comprising, preferably consisting of, an aromatic hydrocarbon, wherein the third impurity does not comprise biphenyl, more preferably the third impurity is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic 25 hydrocarbons (PAH), and mixtures thereof, more preferably selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, and mixtures thereof, and most preferably xylene.

[0063] In various embodiments of said additional purification process,

[0064] (1) the solvent (S1) has a boiling point at a pressure psi of 5 mbar at a temperature TBI equal to or less than 230 °C and / or has a boiling point at a pressure pB2 of 1 bar at a temperature TB2 equal to or higher than 230 °C and / or can dissolve from 5 wt-% to 50 wt-% TBPT with respect to the total weight of the solvent at a temperature Ts in the range of from 100 °C to 235 °C, for example in the range of from 150 °C to 230 °C.

[0065] In another aspect, the present invention relates to a purification method for TBPT comprising dissolving the TBPT in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT, and isolating the obtained TBPT, optionally washing the TBPT with a suitable organic solvent, and optionally drying the obtained TBPT. All embodiments that have been disclosed above in relation to step h) of the inventive process of the first aspect of the invention similarly apply to this aspect. In this aspect, the TBPT may be produced by any conventional process and the purification by activated carbon is carried out using this TBPT produced by any process.

[0066] In another aspect, the present invention relates to 1 ,3,5-triazine,2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT) obtained by a process according to the invention. The TBPT thus obtained is preferably at least 97.0 % pure, preferably at least 97.5 % pure, more preferably at least 98 % pure, even more preferably at least 98.5 % pure. This purity relates to TBPT after steps a) to g) and at least one of d1) and h).

[0067] In various embodiments, the TBPT obtained by the process of the invention comprising at least steps a) to g) and either d1) or h) comprises less than 100 ppm metal impurities selected from aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm. In various embodiments, the TBPT obtained by the process of the invention comprises less than 100 ppm metal impurities selected from aluminum, iron, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm.

[0068] In various embodiments, the above upper limits relate to the totality of all metals in said TBPT preparation.

[0069] In various embodiments, in the obtained TBPT the aluminum content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm. In various embodiments, in the obtained TBPT the iron content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm. In various embodiments, in the obtained TBPT the chromium content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm. In various embodiments, in the obtained TBPT the nickel content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm.

[0070] In still another aspect, the invention is directed to a TBPT preparation comprising less than 100 ppm metal impurities selected from aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm, irrespective of its method of production. In various embodiments, the above upper limits relate to the totality of aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably the totality of all metals in said TBPT preparation. This means that in various embodiments, the total content of aluminum, cadmium, lead, iron, cobalt, chromium, and nickel is less than 100 ppm, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm. This also means that in various embodiments, the total content of metals in said preparation is less than 100 ppm, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm.

[0071] In various embodiments, the total content of aluminum is less than 50 ppm, preferably less than 40 ppm or less than 30 ppm, more preferably less than 20 ppm or less than 15 ppm, even more preferably less than 10 ppm or less than 5 ppm.

[0072] In various embodiments, the total content of arsenic is less than 5 ppm, preferably less than 3 ppm or less than 2 ppm, more preferably less than 1.5 ppm or less than 1.0 ppm, even more preferably less than 0.5 ppm.

[0073] In various embodiments, the total content of cadmium is less than 10 ppm, preferably less than 5 ppm or less than 4 ppm, more preferably less than 3 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0074] In various embodiments, the total content of lead is less than 20 ppm, preferably less than 15 ppm or less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm.

[0075] In various embodiments, the total content of antimony is less than 20 ppm, preferably less than 15 ppm or less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm.

[0076] In various embodiments, the total content of iron is less than 80 ppm or less than 50 ppm, preferably less than 40 ppm or less than 30 ppm, more preferably less than 20 ppm or less than 15 ppm, even more preferably less than 10 ppm or less than 5 ppm.

[0077] In various embodiments, the total content of mercury is less than 10 ppm, preferably less than 5 ppm or less than 4 ppm, more preferably less than 3 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0078] In various embodiments, the total content of cobalt is less than 10 ppm, preferably less than 8 ppm or less than 6 ppm, more preferably less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0079] In various embodiments, the total content of chromium is less than 10 ppm, preferably less than 8 ppm or less than 6 ppm, more preferably less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm. In various embodiments, the total content of nickel is less than 20 ppm, preferably less than 15 ppm or less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm.

[0080] In various embodiments,

[0081] (1) the total aluminum content is less than 20 or less than 15 or less than 10 ppm or less than 5 ppm; (2) the total iron content is less than 40 ppm or less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm;

[0082] (3) the total chromium content is less than 6 ppm, more preferably less than 5 ppm, less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm;

[0083] (4) the total nickel content is less than 10 ppm preferably less than 8 ppm or less than 6 ppm, more preferably less than 5 ppm, less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm; (5) the total content of arsenic is less than 2 ppm, more preferably less than 1.5 ppm or less than 1.0 ppm, even more preferably less than 0.5 ppm;

[0084] (6) the total content of cadmium is less than 4 ppm, more preferably less than 3 ppm or less than 2 ppm, even more preferably less than 1 ppm;

[0085] (7) the total content of lead is less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm;

[0086] (8) the total content of antimony is less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm;

[0087] (9) the total content of mercury is less than 2 ppm, even more preferably less than 1 ppm; and / or, preferably and,

[0088] (10) the total content of cobalt is less than 6 ppm, more preferably less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0089] In a further aspect, the present invention relates to a topical product, preferably a cosmetic product, comprising the TBPT according to the invention, which may be obtained by a process according to the invention.

[0090] Finally, in still another aspect, the present invention relates to the use of the TBPT according to the invention, preferably obtained by a process according to the invention, as a UV filter in a topical product, preferably a cosmetic product, for protecting hair and / or skin of a subject from the damaging effects of UV radiation.

[0091] The present invention will be described with respect to particular embodiments and with reference to certain examples, but the invention is not limited thereto, and it is only defined by the appended claims.

[0092] Detailed Description

[0093] Before describing in detail exemplary embodiments of the present invention, definitions important for understanding the present invention are given. Terms as set forth hereinafter are generally to be understood in their common sense unless indicated otherwise.

[0094] The terms “include” and “comprising” do not exclude other elements and mean that there may be other components in addition to those mentioned. These terms are meant inclusively and therefore include “consisting of’. “Consisting of’ is meant conclusively and means that no further constituents may be present. For the purposes of the present invention, the term “consisting of’ is considered to be a preferred embodiment of the term “comprising”. If hereinafter a group is defined to comprise at least a certain number of embodiments, this is also to be understood to disclose a group, which preferably consists only of these embodiments.

[0095] Where an indefinite or definite article is used when referring to a singular noun, e.g., “a”, “an” or “the”, this includes a plural of that noun unless specifically stated otherwise.

[0096] The term “at least one” means numerically “one or more”. In one embodiment, the term numerically means “one”. In various other embodiments, “at least one” means one, two, three, four, five, six, seven, eight, nine or more, for example 10, 100 or 1000.

[0097] Terms like “obtainable” and “obtained” are used interchangeably. This, e.g., means that, unless the context clearly dictates otherwise, the term “obtained” does not mean to indicate that e.g., an embodiment must be obtained by e.g. the sequence of steps following the term “obtained” even though such a limited understanding is always included by the terms “obtained” as a preferred embodiment.

[0098] Furthermore, the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)" etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operating in other sequences than described or illustrated herein. In case the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)", "i", "ii" etc. relate to steps of a process or use there is no time or time interval coherence between the steps, i.e. the steps may be carried out simultaneously or there may be time intervals of seconds, minutes, hours, days, weeks, months or even years between such steps, unless otherwise indicated in the application as set forth herein above or below.

[0099] It is to be understood that this invention is not limited to the particular methodology, protocols, reagents etc. described herein as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention that will be limited only by the appended claims.

[0100] The terms "about" or “approximately” allow a deviation from the indicated numerical value of ±10 %, preferably ±5 %, more preferably ±2 %, even more preferably ±1 %, and in the most preferred embodiments "about" and “approximately” mean “exactly”. A range delimited by numbers, e.g. "from 80 °C to 120 °C" means that the endpoints and each value within that range are individually disclosed.

[0101] The term “room temperature”, as used herein, relates to 20 °C. The term “standard pressure”, as used herein, relates to 1013 mbar. “Elevated” temperature, as used herein, means a temperature higher than room temperature, typically at least 40°C or higher, for example 50°C or higher, 60°C or higher or 70°C or higher.

[0102] The term “under vacuum” means a reduced pressure in comparison to standard pressure. In various embodiments, the reduced pressure is equal to or lower than 100 mbar, if not explicitly stated otherwise. In another embodiment, the reduced pressure can be equal to or lower than 10 mbar, if not explicitly stated otherwise.

[0103] The term “crystalline form” in relation to TBPT according to the present disclosure comprises in particular the crystalline form A and crystalline form B. However, it is not excluded that there may be additional crystalline forms. In preferred embodiments, TBPT obtained according to the present invention comprises in particular the crystalline form A, as for example described in international patent publications WO 2024 / 160670 A1 and WO 2024 / 160671 A1.

[0104] The term “purity”, as used herein, relates to the purity of a batch that was obtained by a “production process”, as described herein, wherein a product obtained from a production process typically comprises impurities. The purity of a batch may be determined by quantifying the TBPT content in a batch, e.g., by HPLC orGC. The experimental details for the method for quantification is further described in the examples given below. According to the present disclosure, TBPT may show a purity of e.g., 95 wt.-%, 96 wt.-%, 97 wt.-%, 98 wt.-%, 98.5 wt.-%, 99.0 wt.-%, 99.1 wt.-%, 99.2 wt.-%, 99.3 wt.-%, 99.4 wt.-%, 99.5 wt.-%, 99.6 wt.-%, 99.7 wt.-%, 99.8 wt.-%, 99.9 wt.-% or even 100 wt.-%. As used herein, a purity of 98.5 wt.-% may mean a mixture of 98.5 wt.-% TBPT and 1.5 wt.-% of impurities.

[0105] The term “impurities” as used herein relates to chemical compounds in a batch TBPT obtained by a production process that are not TBPT. As such, the term “impurities” includes inorganic and organic impurities. Particularly relevant impurities in the context of the present disclosure are impurities from remaining starting material, intermediate products or solvents that may be used or occur during a production process, and contaminants that may be introduced into the batch TBPT during its production process. Among those impurities there may be problematic impurities due to toxicological concerns, which are for example aromatic hydrocarbons, such as biphenyl or xylene, or halogenated triazines, such as 2,4-bis([1 ,T-biphenyl]-4-yl)-6-chloro-1 ,3,5-triazine (BBCT). Particularly relevant in the context of the present invention are impurities of (heavy) metal contaminations. Metal contaminations preferably comprise heavy metals such as cadmium, lead, iron, cobalt, chromium and nickel, and light metals such as aluminum. Further impurities include mercury, arsenic, and antimony. The list of “impurities” cannot be understood as a comprehensive or conclusive list of impurities. Further impurities that can be determined include, but are not limited to, arsenic, antimony and mercury. In the context of this disclosure, certain known “impurities” are quantified by, e.g., GC or HPLC. The experimental details for the method for quantification is further described in the examples given below. Metal impurities can be determined by Inductively coupled plasma optical emission spectrometer (ICP-OES), as for example described in the examples below. Mercury can be determined by atom absorption spectroscopy (AAS).

[0106] The term “xylene” as referred herein covers all xylene isomers and a mixture thereof comprising 1 ,2-dimethylbenzene, 1 ,3-dimethylbenzene and 1 ,4-dimethylbenzene, corresponding to o / Yho-xylenes, meta-xylenes, para-xylenes, also o-xylenes, m-xylenes, and p-xylenes.

[0107] The term “production process” refers to a process that may comprise the steps of synthesizing, isolating and purifying. The production process may only consist of one or two of these steps and optionally comprises additional steps. The production process is thus not to be understood to be limited to these steps or even the order of the steps, if not stated otherwise.

[0108] The term ‘TBPT’ as used herein has to be understood as abbreviation for the chemical compound name 1.3.5-triazine, 2,4,6-tris[1 ,1’-biphenyl]-4-yl (CAS Number: 31274-51-8, also: 2,4,6-tris([1 ,1'-biphenyl]-4-yl)- 1.3.5-triazine), which is described according to formula (I).

[0109]

[0110] (I).

[0111] TBPT may occur in amorphous form or crystalline form and mixtures thereof. Compound of formula (I) can exist in at least two crystal modifications or in mixtures of the two or more crystalline states. Polymorph type A can be distinguished from polymorph type B by powder X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). Only polymorph type A is suitable for sunscreen application due to the specific UV absorption properties. Moreover, polymorph type B is metastable at room temperature. For more details on these polymorphs, reference is made to international patent publications WO 2024 / 160670 A1 and WO 2024 / 160671 A1 , which are incorporated herein by reference in their entirety.

[0112] The term “raw TBPT” or “TBPT raw” according to the present disclosure, refers to TBPT as a crude product that is obtained after the synthesis but typically prior to purification, such as the TBPT obtained after steps a) to g) and d1) and / or h) of the processes according to the invention. “Raw TBPT” or“TBPT raw” may also be obtained from a standard production process resulting in a product with a higher level of impurities. TBPT raw may comprise TBPT in the crystalline form A.

[0113] The process according to the invention comprises the pH adjustment step as described herein (TBPT raw obtained from inventive process w / pH adjustment) and / or a further purification step comprising activated carbon as described herein (TBPT raw purified by inventive process). The TBPT products resulting from the inventive processes can be further purified by standard purification processes or purification processes as described herein.

[0114] Hence, in a first aspect the present invention relates to a process for the production of 1 ,3,5-triazine, 2, 4, 6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprising the steps of

[0115] a) reacting a 2,4,6-trihalogen-1 ,3,5-triazine with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;

[0116] b) removing the organic solvent after the reaction is completed, preferably by distillation;

[0117] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;

[0118] d) separating the organic phase obtained in step c) and, optionally, washing and drying it; e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0119] f) crystallizing the TBPT from the solution obtained in step e) by cooling;

[0120] g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent, and optionally drying,

[0121] wherein the process further comprises the step(s) of:

[0122] d1) adjusting the pH of the organic phase obtained in step d) to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, prior to drying by addition of a suitable base, preferably sodium hydroxide; and / or

[0123] h) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT, and isolating the obtained crystallized TBPT, optionally washing the TBPT with a suitable organic solvent, and optionally drying the obtained TBPT.

[0124] In various embodiments according to the invention, the process for the production of 1,3,5-triazine,2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprises the steps of

[0125] a) reacting a 2,4,6-trihalogen-1 ,3,5-triazine with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;

[0126] b) removing the organic solvent after the reaction is completed, preferably by distillation;

[0127] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;

[0128] d) separating and washing the organic phase obtained in step c), adjusting the pH of the organic phase to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, by addition of a suitable base, preferably sodium hydroxide, and drying the pH-adjusted organic phase; e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0129] f) crystallizing the TBPT from the solution obtained in step e) by cooling; and

[0130] g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent, and drying.

[0131] In various embodiments according to the invention, the process for the production of 1,3,5-triazine,2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprises the steps of

[0132] a) reacting a 2,4,6-trihalogen-1 ,3,5-triazine with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;

[0133] b) removing the organic solvent after the reaction is completed, preferably by distillation;

[0134] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;

[0135] d) separating, and optionally washing and drying, the organic phase obtained in step c);

[0136] e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0137] f) crystallizing the TBPT from the solution obtained in step e) by cooling;

[0138] g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent, and drying, and

[0139] h) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT, and isolating the crystallized TBPT, optionally washing the TBPT with a suitable organic solvent, and optionally drying the obtained TBPT.

[0140] In various embodiments according to the invention, the process for the production of 1,3,5-triazine,2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprises the steps of

[0141] a) reacting a 2,4,6-trihalogen-1 ,3,5-triazine with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;

[0142] b) removing the organic solvent after the reaction is completed, preferably by distillation;

[0143] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;

[0144] d) separating and washing the organic phase obtained in step c), adjusting the pH of the organic phase to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, by addition of a suitable base, preferably sodium hydroxide, and drying the pH-adjusted organic phase;

[0145] e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0146] f) crystallizing the TBPT from the solution obtained in step e) by cooling;

[0147] g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent, and drying; and, optionally,

[0148] h) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT from the obtained filtrate, isolating the obtained TBPT, washing the TBPT with a suitable organic solvent, and drying the obtained TBPT.

[0149] In various embodiments according to the invention, the process for the production of 1,3,5-triazine,2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprises the steps of

[0150] a) reacting a 2,4,6-trihalogen-1 ,3,5-triazine with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;

[0151] b) removing the organic solvent after the reaction is completed, preferably by distillation;

[0152] c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;

[0153] d) separating and washing the organic phase obtained in step c), adjusting the pH of the organic phase to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, by addition of a suitable base, preferably sodium hydroxide, and drying the organic phase;

[0154] e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;

[0155] f) crystallizing the TBPT from the solution obtained in step e) by cooling;

[0156] g) isolating the crystallized TBPT obtained in step f), followed by washing with a suitable organic solvent, and drying, and

[0157] h) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT from the obtained filtrate, isolating the obtained TBPT, washing the TBPT with a suitable organic solvent, and drying the obtained TBPT.

[0158] In various embodiments, the 2, 4, 6-trihalogen-1 ,3,5-triazine of step a) is 2,4,6-trichloro-1 ,3,5-triazin (cyanuric chloride).

[0159] The suitable organic solvent of step a) is preferably a non-polar solvent, more preferably a linear, branched, or cyclic aliphatic hydrocarbon or aromatic hydrocarbon comprising C1-C20 carbon atoms, optionally substituted with, e.g., an C1-C3 alkyl group, alkyl-aryl ether, or alkyl-alkyl ether, optionally substituted with an alkoxy, halide or carbonyl moiety, more preferably a linear aliphatic hydrocarbon comprising C1-C20 carbon atoms, more preferably hexane or heptane, most preferably heptane. “Non-polar”, as used in relation to a solvent, typically means compound having a dielectric constant (at 0°C) of less than 15.0, preferably less than 10.0.

[0160] In various embodiments, the elevated temperature in step a) is equal to or higher than 90 °C, preferably equal to or higher than 100 °C, more preferably between 90 °C and 120 °C or between 100 °C and 120 °C, most preferably between 105 °C and 115 °C, for example 105 °C to 110 °C and / or 110 to 114 °C.

[0161] It is preferred that the catalyst of step a) is a Lewis acid. The catalyst may be selected from the group consisting of acidic halides, metal alkyl and alkoxides, proton acids, acidic oxides, cation exchange resins and mixtures thereof, or for example selected from the group consisting of AICH, AIBrs, BF3, BCH, BBrs, BeCh, CdCh, ZnCh, GaCH, GaBrs, FeCH, SbCH, BiCH, TiCh, ZrCh, SnCh, UCh, SbCk, and mixtures thereof, more preferably AlCh.

[0162] In various embodiments, the catalyst is used in stoichiometric amounts or in excess. As co-catalysts alcohols, water, HCI, HF, H2SO4, H2PO4, RCOOH (organic acids), sulfonic acids like for example p-toluene sulfonic acid may be used. Most preferably, gaseous HCI is used as co-catalyst. The co-catalysts can also be used in stoichiometric amounts or in excess. In various embodiments, reaction step a) runs particularly well when gaseous HCI is discharged into the reaction mixture.

[0163] Furthermore, reaction step a) can be carried out in ionic fluids like for example 1-butyl-pyridinium chloride - aluminum (HI) chloride and 1-butyl-3-methylimidazolium chloride - aluminum (HI) chloride (See, e.g, 1-ethyl-3-methylimidazolium halogenoaluminate ionic liquids as solvents for Friedel-Crafts acylation reactions of ferrocene. Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry 1999 (1), 63).

[0164] In various embodiments, step a) can be carried out in the absence of a solvent like 1,2-dichlorobenzene.

[0165] In preferred embodiments, the distillation of step b) is carried out under vacuum (>100 mbar).

[0166] In various embodiments, the suitable organic solvent of step(s) c), g), and / or h) is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably it is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably it is selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene.

[0167] In various embodiments, the hydrolyzing step c) comprises the addition of water, sodium hydroxide and an organic solvent, wherein the organic solvent is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably it is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably it is selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene; wherein the hydrolyzing step is preferably carried out at a temperature of from 80 °C to 100 °C, more preferably of from about 85 °C to about 90 °C. The term “hydrolyzing” as used in this context, relates to the hydrolysis of the reaction mixture in which various activated complexes are formed of the aluminum chloride, biphenyl and intermediates, all of which may have impact on the reaction. These complexes are hydrolyzed by the added water due to the aluminum chloride being hydrated and dissolved in the water phase. Some of the organic byproducts may chemically react with or are hydrolyzed by the water.

[0168] In some embodiments, the organic phase of step d) is washed with water at 80 °C to 100 °C, preferably about 90 °C; and / or the drying in step d) is carried out by distillation, preferably azeotropic distillation under vacuum. Preferably, the heating of step e) takes place at a temperature of 130 °C to 160 °C, more preferably at 140 °C to 155 °C, more preferably at about 143 °C to about 150 °C.

[0169] In various embodiments, the crystallization of step f) is carried out by cooling to 30 °C to 50 °C, preferably about 40 °C.

[0170] In various embodiments, in step g), the drying is carried under vacuum, optionally at 90°C to 140 °C, preferably at 90 °C to 110 °C, more preferably at about 100 °C.

[0171] In various embodiments of the production process according to the invention, in step a) compound 2,4,6-trihalogen-1 ,3,5-triazine, preferably 2,4, 6-trichloro-1 ,3, 5-triazin (cyanuric chloride), reacts with biphenyl in a suitable organic solvent, preferably heptane, at an elevated temperature, preferably a temperature between 105 °C to 115 °C, for example 105 °C to 110 °C and / or 110 to 114 °C, in the presence of a catalyst, preferably AlCh. In various embodiments, the catalyst is preferably added in portions to the stirred reaction mixture of 2, 4, 6-trihalogen-1 ,3,5-triazine, preferably 2,4,6-trichloro-1 ,3, 5-triazin (cyanuric chloride), biphenyl and the suitable organic solvent, preferably heptane. In various embodiments, the addition of the catalyst is carried out in 6 to 10 hours, optionally 7 to 9 hours, for example about 8 hours.

[0172] After completion of the reaction, the organic solvent, preferably heptane, is removed in step b), preferably by distillation, more preferably under vacuum (>100 mbar).

[0173] Hydrolyzing step c) of the first aspect is carried out by adding the reaction mixture of step b) to a mixture of water and a suitable organic solvent. In preferred embodiments, the reaction mixture of step b) is added to a mixture of water, sodium hydroxide and a suitable organic solvent, wherein the suitable organic solvent is preferably xylene. In various embodiments, the hydrolyzing step c) is carried out at a temperature of from 80 °C to 100 °C, more preferably about 85 °C to about 90 °C, preferably until completion of hydrolysis.

[0174] In step d) of the inventive process, the organic phase is separated from the aqueous phase, preferably at a temperature of from 80 °C to 100 °C, most preferably about 90 °C. Then, the organic phase is preferably washed with water, more preferably at a temperature of 80 °C to 100 °C, most preferably about 90 °C.

[0175] In various embodiments, alternatively or in addition to step h) of the inventive process, the pH of the organic phase obtained after separating the wash water phase, has been adjusted to pH 1.5 to 4, preferably to pH 2.5 to 3.5, and most preferably to about pH 3.0, by addition of a suitable base, preferably sodium hydroxide (step d1). Then the organic phase is dried, preferably by distillation, more preferably by azeotropic distillation under vacuum.

[0176] In step e) of the process according to the invention, the organic phase of step d) (suspension) is heated, preferably to a temperature of 130 °C to 160 °C, more preferably 140 °C to 155 °C, most preferably about 143 °C to about 150 °C. In various embodiments, optionally, hot filtration is carried out. In step f) of the process according to the invention, the solution of step e) is cooled, preferably to a temperature of 30 °C to 50 °C, more preferably to about 40 °C, for crystallization of TBPT.

[0177] In the following step g), the crystallized product is isolated, preferably by filtration, it is then typically washed with a suitable organic solvent, preferably xylene, and dried, preferably at a temperature of from 90 °C to 140 °C, more preferably 90 °C to 110 °C, most preferably about 100 °C, preferably under vacuum.

[0178] In various preferred embodiments, the process according to the invention comprises a step h), alternatively or in addition to process step d1), wherein the TBPT obtained in step g) is dissolved in a suitable organic solvent at elevated temperature in the presence of activated carbon, wherein the activated carbon is afterwards removed, for example by filtration, the TBPT is crystallized optionally from the filtrate, isolated, washed with a suitable organic solvent, and dried to obtain the TBPT product.

[0179] Preferably, in step h),

[0180] (1) the activated carbon is a mixture of activated carbon and bentonite (for example CAS No. 1302- 78-9); and / or

[0181] (2) the suitable solvent is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, more preferably it is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene; and / or

[0182] (3) the elevated temperature is from 130 °C to 160 °C, more preferably 140 °C to 155 °C, most preferably about 150 °C; and / or

[0183] (4) removing of the activated carbon is carried out by filtration, more preferably at 130 °C to 160 °C, more preferably at 140 °C to 155 °C, most preferably at about 150 °C; and / or

[0184] (5) crystallization is carried out by cooling to 30 °C to 50 °C, more preferably about 40 °C; and / or (6) isolation is carried out by filtration; and / or

[0185] (7) drying is carried out under vacuum, more preferably at 90 °C to 110 °C, more preferably about 100 °C.

[0186] The removal of the activated carbon and optionally bentonite in step (4) may be further facilitated by the addition of cellulose, which is also removed by the filtration but helps to entrap the activated carbon.

[0187] In various embodiments, in which purification step h) is part of the process according to the invention, TBPT obtained in step g), is dissolved in a suitable organic solvent at elevated temperature in the presence of activated carbon. In preferred embodiments, the suitable organic solvent is xylene. The elevated temperature is preferably a temperature of from of from 130 °C to 160 °C, more preferably of from 140 to 155 °C, more preferably about 150 °C. In preferred embodiments, the activated carbon is a mixture of activated carbon and bentonite (for example CAS No. 1302-78-9). Afterwards, in various embodiments, cellulose is added to the resulting solution. In a subsequent step, the activated carbon is removed, preferably by filtration, more preferably at a temperature of from 130 °C to 160 °C, preferably 140 °C to 155 °C, more preferably about 150 °C. Then, the solution is cooled to a temperature of 30 °C to 50 °C, preferably about 40 °C, and the product is isolated, preferably by filtration, washed with a suitable solvent, preferably xylene, and dried, preferably at a temperature of 90 °C to 110 °C, most preferably about 100 °C, preferably under vacuum, to obtain the TBPT product.

[0188] Step h) can also be performed independently of the previous steps of the inventive processes and may thus be used to purify any TBPT (formulation), including those produced by other methods than those described herein. In such embodiments, the invention features a method for the purification of (crude) TBPT, in particular purification from metal impurities, said method comprising dissolving the TBPT in a suitable organic solvent at elevated temperature in the presence of activated carbon, wherein the activated carbon is afterwards removed, for example by filtration, the TBPT is crystallized optionally from the filtrate, isolated, washed with a suitable organic solvent, and dried to obtain the purified TBPT product. All preferred embodiments disclosed herein for step h) of the inventive process are similarly applicable to such purification method.

[0189] In various embodiments, the obtained product has a TBPT purity in the range of from 97.0 wt.-% to 100 wt.-% with respect to the total weight of the product, more preferably in the range of from 97.5 wt.-% to 100 wt.-%, more preferably in the range of from 99.0 wt.-% to 100 wt.-%, most preferably in the range of from 99.2 wt.-% to 100 wt.-%, e.g., equal to or more than about 97.5 wt.-%, equal to or more than about 99.0 wt.-%, or equal to or more than about 99.2 wt.-%.

[0190] Preferably, in the obtained TBPT product according to the invention (heavy) metal impurities are reduced, in comparison to processes of the state of the art, which do not comprise step d1) and / or h) of the process according to the invention. In particular metal impurities of aluminum, iron, chromium and nickel are reduced.

[0191] In various embodiments, in the TBPT obtained by the process of the invention comprising at least steps a) to g) and either d1) or h) the aluminum content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm.

[0192] In various embodiments, in the TBPT obtained by the process of the invention comprising at least steps a) to g) and either d1) or h) the iron content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm.

[0193] In various embodiments, in the TBPT obtained by the process of the invention comprising at least steps a) to g) and either d1) or h) the chromium content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm. In various embodiments, in the TBPT obtained by the process of the invention comprising at least steps a) to g) and either d1) or h) the nickel content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm.

[0194] In various embodiments, the TBPT obtained by the process of the invention comprising at least steps a) to g) and either d1) or h) comprises less than 100 ppm metal impurities selected from aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm. In various embodiments, the TBPT obtained by the process of the invention comprises less than 100 ppm metal impurities selected from aluminum, iron, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm. These values relate to the total amounts of all listed metals, i.e. for example less than 100 ppm of aluminum, cadmium, lead, iron, cobalt, chromium, and nickel combined.

[0195] In various embodiments, the above upper limits relate to the totality of all metals in said TBPT preparation, i.e. all metal including those listed above and all other metals not listed above. The total metal content in the TBPT may thus be less than 100 ppm, preferably less than 70 or less than 50 ppm.

[0196] In various embodiments, in the TBPT obtained by the process of the invention comprising at least step h) the aluminum content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm.

[0197] In various embodiments, in the TBPT obtained by the process of the invention comprising at least step h) the iron content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm.

[0198] In various embodiments, in the TBPT obtained by the process of the invention comprising at least step h) the chromium content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm.

[0199] In various embodiments, in the TBPT obtained by the process of the invention comprising at least step h) the nickel content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm.

[0200] In various embodiments, the TBPT obtained by the process of the invention comprising at least step h) comprises less than 100 ppm metal impurities selected from aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm. In various embodiments, the TBPT obtained by the process of the invention comprises less than 100 ppm metal impurities selected from aluminum, iron, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm. These values relate to the total amounts of all listed metals, i.e. for example less than 100 ppm of aluminum, cadmium, lead, iron, cobalt, chromium, and nickel combined.

[0201] In various embodiments, the above upper limits relate to the totality of all metals in said TBPT preparation, i.e. all metal including those listed above and all other metals not listed above. The total metal content in the TBPT may thus be less than 100 ppm, preferably less than 70 or less than 50 ppm.

[0202] In still another aspect, the invention is directed to a TBPT preparation in general, i.e. not necessarily obtained according to the processes of the present invention, comprising less than 100 ppm metal impurities selected from aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm, irrespective of its method of production. In various embodiments, the above upper limits relate to the totality of all metals in said TBPT preparation.

[0203] In various embodiments, in such a TBPT preparation the aluminum content is less than 50 ppm, preferably less than 40 ppm or less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm.

[0204] In various embodiments, in such a TBPT preparation the iron content is less than 80 ppm or less than 50 ppm, preferably less than 40 ppm or less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm.

[0205] In various embodiments, in such a TBPT preparation the chromium content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm, preferably less than 8 ppm or less than 6 ppm, more preferably less than 5 ppm, less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0206] In various embodiments, in such a TBPT preparation the nickel content is less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm preferably less than 8 ppm or less than 6 ppm, more preferably less than 5 ppm, less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0207] In various embodiments, the total content of arsenic is less than 5 ppm, preferably less than 3 ppm or less than 2 ppm, more preferably less than 1.5 ppm or less than 1.0 ppm, even more preferably less than 0.5 ppm.

[0208] In various embodiments, the total content of cadmium is less than 10 ppm, preferably less than 5 ppm or less than 4 ppm, more preferably less than 3 ppm or less than 2 ppm, even more preferably less than 1 ppm. In various embodiments, the total content of lead is less than 20 ppm, preferably less than 15 ppm or less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm.

[0209] In various embodiments, the total content of antimony is less than 20 ppm, preferably less than 15 ppm or less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm.

[0210] In various embodiments, the total content of mercury is less than 10 ppm, preferably less than 5 ppm or less than 4 ppm, more preferably less than 3 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0211] In various embodiments, the total content of cobalt is less than 10 ppm, preferably less than 8 ppm or less than 6 ppm, more preferably less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm.

[0212] In various embodiments, the 1 ,3,5-triazine, 2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT) product obtained from the process according to the invention as described above, i.e. either comprising steps a) to f) and at least one of d1) and h) or comprising at least step h), is further purified. Suitable further purification processes are known in the art and may comprise those described in WO 2024 / 160670 A1 and WO 2024 / 160671 A1.

[0213] In various embodiments, such purification process comprises:

[0214] A) providing the obtained TBPT product, wherein said TBPT may comprise at least a first impurity consisting of one or more halogen-comprising triazine, and a second impurity consisting of biphenyl;

[0215] B) suspending the TBPT in a first solvent (S1), preferably isopropyl palmitate, thereby providing a first suspension;

[0216] C) heating the first suspension to a temperature of more than 200 °C, preferably more than 210 °C, more preferably about 220 °C, preferably under vacuum, thereby providing a heated first suspension or a first solution of TBPT in the first solvent (S1);

[0217] D) keeping the heated first suspension or first solution of TBPT at a temperature between 100 °C and 235 °C, preferably 150 °C to 230 °C, more preferably 200 °C to 230 °C, most preferably about 223 °C, and a pressure of from 5 mbarto standard pressure, preferably from 900 mbar to standard pressure;

[0218] E) cooling the heated first suspension or the first solution to a temperature of 40 °C to 90 °C, preferably 50 °C to 80 °C, more preferably about 70 °C, to allow crystallization; and F) isolating the crystals from the solution, preferably by filtration, washing, preferably with isopropanol, and drying to obtain a further purified TBPT product.

[0219] In various embodiments, (1) the halogen-comprising triazine is selected from chlorine-comprising triazines, brominecomprising triazines, and a mixture thereof, preferably it is 1 ,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1 ,3,5-triazine, 2,4-bis([1,1'-biphenyl]-4-yl)-6-chloro (BBCT), and most preferably it is 1,3,5- triazine, 2,4-bis([1 ,1'-biphenyl]-4-yl)-6-chloro (BBCT); and / or

[0220] (2) the TBPT of step A) further comprises a third impurity, the third impurity comprising, preferably consisting of, an aromatic hydrocarbon, wherein the third impurity does not comprise biphenyl, more preferably the third impurity is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic 25 hydrocarbons (PAH), and mixtures thereof, more preferably selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, and mixtures thereof, and most preferably xylene.

[0221] Both the first and the second impurity, but in particular the second impurity, i.e. biphenyl, are side products of the production process of TBPT. Both impurities comprise aromatic entities, which are known to be capable of increasing the risk of diseases such as cancer. Hence, in various embodiments, the further purification process according to claim 10 provides a further purified TBPT product with reduced amounts of such impurities.

[0222] Preferably, the halogen-comprising triazine of the first impurity of TBPT is selected from the group consisting of chlorine-comprising triazines, bromine-comprising triazines, and a mixture thereof. The halogen-comprising triazines, such as the chlorine-comprising triazine and bromine-comprising triazine include 1 ,3,5-triazines, in particular phenyl substituted, such as 2,4,6-trisphenyl, or biphenyl substituted, such as 2,4-di([1 ,1’-biphenyl]-4-yl), 1 ,3,5-triazines in which one or more hydrogen atoms are replaced by halogen atoms, such as chloro or bromo, for example on the 1 ,3,5-triazine ring or the phenyl rings. In various embodiments, the first impurity more preferably is 1,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1 ,3,5-triazine, 2,4-bis([1,1'-biphenyl]-4-yl)-6-chloro (BBCT), and most preferably is 1 ,3,5-triazine, 2,4-bis([1,1'-biphenyl]-4-yl)-6-chloro (BBCT).

[0223] In various embodiments, the amount of the first impurity is equal to or less than 800 ppm by weight with respect to the total weight of the TBPT product before further purification, more preferably equal to or less than 600 ppm by weight, and most preferably equal to or less than 400 ppm by weight. Reduction of impurities, preferably the reduction of the first impurity, further reduces the risk of side effects if used, i.e., in cosmetic products.

[0224] In various embodiments, the first impurity is equal to or more than 0.01 ppm by weight with respect to the total weight of the TBPT product before further purification, preferably equal to or more than 0.1 ppm by weight with respect to the total weight of the TBPT product before further purification, more preferably equal to or more than 1 ppm by weight, still more preferably equal to or more than 10 ppm by weight and most preferably equal to or more than 100 ppm by weight. In various embodiments, the amount of the second impurity of the TBPT product before further purification is equal to or less than 3000 ppm by weight with respect to the total weight of the TBPT product, more preferably equal to or less than 600 ppm by weight, and most preferably equal to or less than 300 ppm by weight.

[0225] In further various embodiments, the amount of the second impurity is equal to or more than 0.01 ppm by weight with respect to the total weight of the TBPT product before further purification, more preferably equal to or more than 0.1 ppm by weight, still more preferably equal to or more than 1 ppm by weight, and even still more preferably equal to or more than 10 ppm by weight, and most preferably equal to or more than 100 ppm by weight.

[0226] In the production process for TBPT, preferably an aromatic solvent is used, as described herein above. This aromatic solvent can be a condensed aromatic system. Examples for such solvents are benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, more preferably xylene. However, such aromatic compounds are undesirable due to health concerns in particular for use in topical products to be used by humans. Thus, it is beneficial to further reduce the amount of such solvent in the resulting TBPT product, for application in cosmetic products.

[0227] In various embodiments, the TBPT product may further comprise a third impurity, the third impurity comprising, preferably consisting of, an aromatic hydrocarbon other than biphenyl. The third impurity may comprise an aromatic hydrocarbon or consist of an aromatic hydrocarbon other than biphenyl. Preferably, the one or more aromatic hydrocarbon of the third impurity is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably is selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably is xylene. This impurity may stem from residual solvent of the production method of TBPT.

[0228] In various embodiments, the amount of the third impurity is equal to or lower than 4000 ppm by weight with respect to the total weight of the TBPT product before further purification, preferably equal to or lower than 800 ppm by weight, and more preferably equal to or lower than 400 ppm by weight. Preferably, the amount of the third impurity is equal to or more than 5 ppm by weight with respect to the total weight of the TBPT product before further purification, preferably equal to or more than 10 ppm by weight, and more preferably equal to or more than 20 ppm by weight.

[0229] The first solvent (S1) may have, in various embodiments, a boiling point Bi at a pressure psi of 5 mbar, wherein the boiling point Bi is at a temperature TBI equal to or lower than 235 °C, preferably equal to or lower than 230 °C. Furthermore, preferably, the first solvent (S1) has a boiling point B2 at a pressure pB2 of 1 bar, wherein the boiling point B2 is at a temperature TB2 equal to or higher than 230 °C, preferably 235 °C. It is preferably, but not necessarily needed, that the first solvent (S1) can dissolve from 5 wt.-% to 50 wt.- % TBPT with respect to the total weight of the first solvent (S1) at a temperature Ts in the range of from 100 °C to 235 °C, for example in a range of from 150 °C to 230 °C.

[0230] Preferably, the further compound, for example the solvent (S1), is selected from the group consisting of esters, triglycerides, vegetable oils, modified vegetable oils, carbonates, hydrocarbons (preferably other than the aromatic hydrocarbons of the third impurity), alcohols, ethers, and mixtures thereof, preferably the further compound is an ester of a linear or branched, preferably linear, saturated or unsaturated, preferably saturated, C6-C50 fatty acid, preferably C6-C25 fatty acid.

[0231] Preferred esters are selected from the group consisting of myristates, palmitates, benzoates, laurates and mixture thereof.

[0232] A preferred myristate is isopropyl myristate.

[0233] A preferred palmitate is isopropyl palmitate.

[0234] Preferred benzoates are selected from the group consisting of C12-C15 alkyl benzoates, dipropylene glycol dibenzoate, methyl gluceth-20 benzoate, and mixtures thereof.

[0235] Especially preferable esters are selected from the group consisting of C12-C15 alkyl benzoate, caprylyl caprylate / caprate, cetearyl ethylhexanoate, cetearyl isononanoate, cetyl palmitate, coco-caprylate, coco-caprylate / caprate, coco-caprylate / caprate, decyl oleate, oleyl oleate, dibutyl adipate, ethylhexyl palmitate, ethylhexyl stearate, hexyl laurate, hexyldecyl stearate, isopropyl stearate, octyl stearate, isopropyl myristate, isopropyl palmitate, myristyl myristate, oleyl erucate, propylene glycol dicaprylate / dicaprate, propylheptyl caprylate, PEG-7 glyceryl cocoate, cetearyl isononanoate, and mixtures thereof.

[0236] Preferable ethers are dicaprylyl ether and PPG-15 stearyl ether.

[0237] Preferred alcohols are selected from the group consisting of octyl dodecanol, hexyl decanol, oleyl alcohol, and mixtures thereof.

[0238] Preferably, the hydrocarbons are selected from the group consisting of hydrogenated polyisobutene, undecane, tridecane, dioctylcyclohexane, and mixtures thereof.

[0239] Preferred triglycerides are selected from the list consisting of caprylic / capric triglyceride, caprylic / capric triglyceride, cocoglycerides, and mixtures thereof.

[0240] Preferred vegetable oils are butyrospermum parkii, elaeis guineensis (palm) oil, passiflora incarnata seed oil, shorea stenoptera butter, and mixtures thereof. Preferably, modified vegetable oils are selected from the group consisting of butyrospermum parkii butter and olus oil.

[0241] Most preferably, the further compound is isopropyl palmitate (IPP).

[0242] Isopropyl palmitate filtrate can be used several times before it has to be recycled. Recycling methods: (1) distillation or (2) washing with aqueous bases or acids or (3) adsorption of impurities using specific absorbents like charcoal or silica gel or zeolites or activated carbon or cellulose or diatomaceous earth or kieselgur or other siliceous sedimentary rock or combinations of (1), (2) and (3). Adsorbents are used usually in the form of spherical pellets, rods, moldings, or monoliths with a hydrodynamic radius between 0.25 and 5 mm. They should have high abrasion resistance, high thermal stability and small pore diameters, which results in higher exposed surface area and hence high capacity for adsorption.

[0243] The procedure can also be carried out at a higher concentration using a TBPT suspension (14-50% TBPT).

[0244] Furthermore, it has been found that TBPT occurs in two crystalline polymorph forms, herein referred to as polymorph types A and B or (crystalline) forms A and B. Crystalline form A can be distinguished from crystalline form B by Xray powder diffraction spectroscopy. It was previously observed that the ratio of the amounts of these two crystalline forms varies depending on the conditions used in the production process of TBPT. It was observed that in particular crystalline form A shows thermal stability at temperatures around 15 °C to 45 °C. Hence, while crystalline form B shows also long storage times, crystalline form A of TBPT has improved storability in comparison to form B. Furthermore, form A of TBPT is suitable for sunscreen application due to the specific UV filter properties, i.e., the UV absorption spectrum of form A.

[0245] Thus, in various embodiments, the TBPT product comprises preferably at least a part of the TBPT, more preferably the total TBPT, in a crystalline form A, which, in an X-ray powder diffractogram at room temperature using Cu-Ka radiation, shows at least 3 of the 5 following reflexes, given in 20 values: 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2 and 24.4 ± O.2°0. More preferably, the crystalline form A shows in an X-ray powder diffractogram at room temperature using Cu-Ka radiation, at least the following three reflexes 11.6 ± 0.2, 17.8 ± 0.2 and 21.1 ± O.2°0, and preferably shows at least the following five reflexes 11.6 ± 0.2, 17.8 ± 0.2, 21.1 ± 0.2, 23.4 ± 0.2 and 24.4 ± O.2°0.

[0246] In various embodiments, in comparison to the form B form A provides the optimal UV absorption spectrum for sunscreen applications. Hence, it is beneficial to have most of the TBPT present in the product in form A. Thus, preferably, the amount of TBPT in crystalline form A is more than 50 wt.-% with respect to the total weight of the TBPT, preferably more than 60 wt.-%, more than 65 wt.-%, more than 70 wt.-%, more than 75 wt.-%, more than 80 wt.-%, more than 81 wt.-%, more than 82 wt.-%, more than 83 wt.-%, more than 84 wt.-%, more than 85 wt.-%, more than 86 wt.-%, more than 87 wt.-%, more than 88 wt.-%, more than 89 wt.-%, more than 90 wt.-%, more than 91 wt.-%, more than 92 wt.-%, more than 93 wt.-%, more than 94 wt.-%, more than 95 wt.-%, more than 96 wt.-%, more than 97 wt.-%, more than 98 wt.-%, more than 99 wt.-%, and most preferably 100 wt.-%. Preferably, the crystalline form A exhibits an endothermic peak in a DSC curve from 221 °C to 256 °C, wherein the DSC curve is measured by a differential scanning calorimeter at a scan rate of 10°C per minute. More preferably, the crystalline form A, which in a DSC curve exhibits an endothermic peak in a DSC curve from about 221 °C to about 256 °C, further preferably wherein the enthalpy AH measured at said endothermic peak is in the range from about 35 J / g to about 50 J / g, more preferably wherein the enthalpy AH measured at said endothermic peak is in the range from about 38 J / g to about 45 J / g.

[0247] In various embodiments, the polymorphic forms A and B are enantiotropic to each other. The transition temperature between the two forms is in the range of 230 °C to 250°C. Heating TBPT to this high temperature induces a phase transformation from the low temperature stable form A to the high-temperature stable form B. The two forms presumably represent an enantiotropic system of polymorphic forms, but the transformation is not readily reversed upon cooling.

[0248] Form A is suitable for sunscreen application due to the specific UV absorption properties. However, biphenyl and xylene in the TBPT product are problematic aromatic hydrocarbons due to toxicological concerns. It is not possible to significantly reduce the impurities by multiple recrystallizations from xylene or from xylene I biphenyl mixtures because the low-temperature stable form A readily incorporates small amounts of almost any solvent. The further purification process of the obtained TBPT product as described herein above can reduce these impurities as described in more detail in WO 2024 / 160670 A1 and WO 2024 / 2160671 A1.

[0249] Thus, in preferred embodiments, the TBPT obtained by the inventive processes is further purified, wherein the further purification steps comprise the following:

[0250] A) providing the obtained TBPT product according to the invention, wherein said TBPT may comprise at least a first impurity, the first impurity consisting of one or more halogen-comprising triazine, and a second impurity consisting of biphenyl;

[0251] B) suspending (in a suspension step) the TBPT in a first solvent (S1), preferably isopropyl palmitate, thereby providing a first suspension;

[0252] C) heating (in a heating step) the first suspension to a temperature T 1 , which is more than 200 °C, preferably more than 210 °C, more preferably about 220 °C, preferably under vacuum, thereby providing a heated first suspension or a first solution of TBPT in the first solvent (S1);

[0253] D) keeping (in a temperature keeping step) the heated first suspension or first solution of TBPT at a temperature T2 between 100 and 235 °C, preferably 150 to 230 °C, more preferably 200 to 230 °C, more preferably 220 °C to 223 °C, most preferably about 223 °C, and a pressure pi of from 5 mbar to standard pressure, preferably from 900 mbarto standard pressure;

[0254] E) cooling (in a cooling step) the heated first suspension or the first solution to a temperature T3 of 40 to 90 °C, preferably 50 to 80 °C, more preferably about 70 °C to allow crystallization; f) isolating (in an isolating step) the crystals from the solution, preferably by filtration, washing, preferably with isopropanol, and drying to obtain a further purified TBPT product. In various embodiments, the further TBPT purification may comprise a step of treating the TBPT with a second solvent (S2). For example, the isolating step may comprise the steps of filtering and washing the crystals with at least one second solvent (S2).

[0255] In various embodiments, the second solvent (S2) is not miscible with water, preferably is a hydrocarbon solvent, more preferably is selected from the list consisting of toluene, mesitylene, xylene, and mixtures thereof. These additional steps further improve the purity of the final product in view of the first and the second impurity comprised in the TBPT product prior to the further purification steps.

[0256] In various embodiments, the suspending step preferably comprises the step of adding the TBPT to the suspension in an amount in the range of from 5 wt-% to 50 wt-% with respect to the total weight of the first suspension.

[0257] In another embodiment, in the heating step the temperature Ti is in the range of from 100 °C to 235 °C, preferably in the range of from 150 °C to 230 °C more preferably 200 °C to 230 °C, most preferably about 223 °C, at a pressure of from 5 mbarto standard pressure, preferably from 900 mbarto standard pressure. Likewise, in the temperature keeping step, the pressure pi is preferably in the range of from 5 mbar to standard pressure, more preferably from 900 mbarto standard pressure.

[0258] In various embodiments, in the cooling step the temperature T3 is in the range of from 40 °C to 90 °C, preferably 50 °C to 80 °C, more preferably 60 °C to 80 °C, more preferably 65 °C to 75 °C, most preferably about 70 °C. This ensures optimal conditions for TBPT crystallization and filtration, as crystallization tends to improve at lower temperatures and filtration performs better at higher temperatures due to the reduced viscosity.

[0259] It has previously been found that with processes known from the prior art, it is not possible to significantly reduce the impurities by multiple recrystallizations from xylene or from xylene I biphenyl mixtures because the low-temperature stable form A readily incorporates small amounts of almost any solvent. These small amounts of the solvent cannot be removed from the crystals by other means such as evaporation. However, by using the further purification step as described herein, the problematic compounds, i.e., the first, second, and optionally third impurities, can be removed by replacement by the solvent (S1).

[0260] The particle size distribution (PSD) of the TBPT crystals is controlled by the nucleation and growth rates during crystallization, which in turn are affected by the supersaturation in the crystallizer. Therefore, in order to manage the PSD and impurities in the crystallization process, it is imperative to consider supersaturation, nucleation rate, and growth rate in the crystallizer. Further control of PSD can be achieved by addition of seeding crystals. Finally, PSD of TBPT easily can be adjusted by grinding of the product or by Ostwald ripening in TBPT suspensions.

[0261] Furthermore, in another aspect, the present invention relates to 1 ,3,5-triazine,2,4,6-tris[1 ,1’-biphenyl]-4-yl (TBPT) as obtained by a process according to the invention (production process with steps a) to f) and d1) and / or h) or purification process including at least step h)) further including the above additional purification process of steps A) to E).

[0262] In another aspect, the present invention relates to a topical product, for example a cosmetic product, comprising the TBPT according to the invention.

[0263] Finally, in still another aspect, the present invention relates to the use of the obtained TBPT according to the invention as a UV filter in a topical product, such as a cosmetic product for protecting hair and / or skin of a subject from the damaging effects of UV radiation.

[0264] In various embodiments, the present invention relates to TBPT according to the present invention for use as a UV filter in a topical product, such as a cosmetic product for protecting hair and / or skin of a subject from the damaging effects of UV radiation.

[0265] Examples

[0266] The present invention is further illustrated by the following examples.

[0267] Quantification of impurities

[0268] GC analysis was used for quantification of 2-propanol, xylene (mix of isomers), biphenyl, isopropyl palmitate. Instrument Agilent 6850-2 GC. Column: Agilent HP-5, 30 m x 320 pm x 0.25 pm. Oven temperature: 3 min at 70 °C, 50 K / min —> 300°C; 5 min at 300 °C. Sample preparation: Samples were completely dissolved in 1 ,4-dioxane at 80 °C (filtration of turbid solution after cooling to 20 °C). Detector: FID. Calibration with external standards of 2-propanol, xylene (mix of isomers), biphenyl, isopropyl palmitate. HPLC analysis was used for quantification of TBPT and BBCT. Instrument: Agilent 1200 HPLC. Column: Phenomenex C18 / 5 pm, length 150 mm. Oven temperature: 40 °C. Injection volume: 5 pL. Eluent: 900 parts acetonitrile + 50 parts tetrahydrofuran + 50 parts water (isocratic elution). Sample preparation: Samples were completely dissolved in tetrahydrofuran. Detector: DAD. Calibration with external standards of TBPT and BBCT.

[0269] ICP AES

[0270] Inductively coupled plasma optical emission spectrometer (ICP-OES) was used for quantification of metal impurities. Samples and blanks were prepared with a digestion system and diluted with deionized water. Metals in digested samples were determined using an iCAP 7400 Duo (Thermo Fisher Scientific, Germany). Calibration was done by external standard method with commercially available elemental standard solutions.

[0271] Example 1

[0272] Comparative example (CE1): Preparation and purification of TBPT

[0273] 311 kg cyanuric chloride, 3200 kg biphenyl (molten) and 1000 kg heptane are charged in a vessel (T=105-110 °C). At 110 °C, 450 kg aluminum chloride is added in portions to the stirred reaction mixture depending on the temperature development. After the aluminum chloride dosing is finalized in 4 h, the reaction mass is stirred for approx. 6 hours at 110-114 °C until the reaction is completed. Afterward, heptane is removed under vacuum (>100 mbar) by distillation. The reaction mixture is hydrolyzed by carefully adding it to a mixture of 3900 kg water, 50 kg sodium hydroxide and 2400 kg xylene at 85 °C. The mixture is stirred at 85-90 °C for approx. 30 min until complete hydrolysis. The lower aqueous phase is separated from the organic product suspension at 90 °C. Then the organic phase (suspension) is washed with 1300 kg water at 90°C. Afterwards, the organic phase (suspension) is dried by azeotropic distillation under vacuum. Water is completely removed from the suspension. By heating the yellow suspension to 143-150 °C, the product dissolves and a turbid solution is obtained. Hot filtration is performed to remove traces of insoluble impurities. Within 4 h, the orange to brown solution is cooled to 40 °C to obtain the crystalline TBPT. The product is isolated by filtration, washed with 2000 kg xylene, and dried at 100 °C under vacuum. (= TBPT raw).

[0274] Inventive examples (IE1 & IE2)

[0275] IE1: pH adjustment of the organic phase before clear filtration

[0276] The process was the same as in comparative example (CE1), but as an additional step, the pH of the organic phase obtained after separation of the wash water phase was adjusted to pH = 3 by adding sodium hydroxide. The products were analyzed on their metal content using spectrometry (ICP AES method) and calibration of the instrument with commercially available standards.

[0277] Table 1 : Metal content of TBPT raw obtained from standard vs. inventive process w / pH adjustment

[0278] < < <

[0279]

[0280] Table 1 shows that the pH adjustment of the organic phase reduces the corrosion potential of the organic product phase in downstream processing. Contamination of TBPT with Chromium and Nickel, which are strong indicators for metal corrosion, is strongly reduced.

[0281] IE2: Addition of activated carbon

[0282] 500 kg TBPT raw as obtained in CE1 is mixed with xylene (approx. 7 % TBPT). 20 kg of a mixture of bentonite and activated carbon is charged to the vessel and the suspension is heated to 150°C and kept at this temperature for 2h. During this process TBPT raw dissolves completely in xylene. 10 kg of cellulose is added, and the product solution is filtered at 150°C to remove the activated carbon-bentonite-mixture. Within 4 h, the solution is cooled to 40°C to obtain the crystalline TBPT. The product is isolated by filtration, washed with 1000 kg of xylene, and dried at 100°C under vacuum.

[0283] The products were analyzed on their metal content using spectrometry (ICP AES method) and calibration of the instrument with commercially available standards.

[0284] Table 2: Metal content of TBPT raw before and after inventive treatment according to IE2

[0285] < < < < < <

[0286]

[0287] The results in Table 2 demonstrate the reduction of metal contamination in TBPT raw by the inventive process.

[0288] For further purification and reduction of organic impurities, the TBPT is then subjected to the following purification protocol:

[0289] TBPT raw is made into a slurry in isopropyl palmitate (approx. 13 %). The suspension is heated under vacuum to 220°C. During this process first xylene and then at 10 mbar biphenyl is removed by distillation. At 220°C some isopropyl palmitate is removed and the TBPT concentration is increased to about 15 %. Vacuum is removed and the product is solved at 223°C. Slow cooling of the stirred solution to 70°C leads to crystallization of the product. The product is filtered at 70°C, washed with isopropanol and dried. (= purified TBPT raw).

[0290] To determine to what extent the purification in isopropyl palmitate (IPP) has an effect on the concentration of metal impurities in TBPT, a comparative example was carried out in which the preparation and purification of TBPT was done as described for comparative example 1 (CE1) above, followed by purification in isopropyl palmitate (IPP). It was found that purification in IPP has no effect on the metal impurities in TBPT:

[0291] Table 3: Metal content of TBPT raw purified by treatment in IPP

[0292]

[0293]

Claims

Claims1. Process forthe production of 1 ,3,5-triazine, 2,4, 6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprising the steps ofa) reacting a 2,4,6-trihalogen-1 ,3,5-triazine, preferably 2,4,6-trichloro-1 ,3,5-triazine (cyanuric chloride), with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;b) removing the organic solvent after the reaction is completed, preferably by distillation;c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;d) separating, and optionally washing and drying, the organic phase obtained in step c);d1) adjusting the pH of the organic phase obtained in step d) to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, prior to drying by addition of a suitable base, preferably sodium hydroxide; e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;f) crystallizing the TBPT from the solution obtained in step e) by cooling;g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent and drying,wherein the process, optionally, further comprises the step of:h) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT, and isolating the obtained TBPT, optionally washing the TBPT with a suitable organic solvent, and optionally drying the obtained TBPT.

2. Process forthe production of 1 ,3,5-triazine, 2,4, 6-tris[1 ,1’-biphenyl]-4-yl (TBPT), comprising the steps ofa) reacting a 2, 4, 6-trihalogen-1 ,3,5-triazine, preferably 2, 4, 6-trichloro-1 ,3,5-triazine (cyanuric chloride), with biphenyl in a suitable organic solvent at elevated temperature in the presence of a catalyst;b) removing the organic solvent after the reaction is completed, preferably by distillation;c) hydrolyzing the reaction mixture obtained in step b) by the addition of water and a suitable organic solvent;d) separating, and optionally washing and drying, the organic phase obtained in step c);e) heating the organic phase obtained in step d) to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof;f) crystallizing the TBPT from the solution obtained in step e) by cooling;g) isolating the crystallized TBPT obtained in step f), optionally followed by washing with a suitable organic solvent and drying, andh) dissolving the TBPT obtained in step g) in a suitable organic solvent at elevated temperature in the presence of activated carbon, removing the activated carbon, crystallizing the TBPT, andisolating the obtained TBPT, optionally washing the TBPT with a suitable organic solvent, and optionally drying the obtained TBPT.

3. The process according to claim 1 or 2, wherein in step a)(1) the suitable organic solvent is a non-polar solvent, preferably a linear, branched, or cyclic aliphatic hydrocarbon or aromatic hydrocarbon comprising C1-C20 carbon atoms, optionally substituted with, e.g., an C1-C3 alkyl group, alkyl-aryl ether, or alkyl-alkyl ether, optionally substituted with an alkoxy, halide or carbonyl moiety, more preferably a linear aliphatic hydrocarbon comprising C1-C20 carbon atoms, more preferably hexane or heptane, most preferably heptane.

4. The process according to any one of claims 1 to 3, wherein in step a)(1) the catalyst is selected from the group consisting of Lewis acids, acidic halides, metal alkylates and alkoxides, proton acids, acidic oxides, cation exchange resins and mixtures thereof, preferably selected from the group consisting of AICH, AIBrs, BF3, BCH, BBrs, BeCL, CdCL, ZnCL, GaCH, GaBrs, FeCH, SbCH, BiCH, TiCh, ZrCh, SnCh, UCh, SbCk, and mixtures thereof, more preferably AlCh; and / or(2) the elevated temperature is higher than 90 °C, preferably higher than 100 °C, more preferably between 100 °C and 120 °C, for example between 105 °C and 110 °C.

5. The process according to any one of the preceding claims, wherein the suitable organic solvent of step(s) c), g) and / or h) is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably it is selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably it is selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene.

6. The process according to any one of the preceding claims, wherein(1) the distillation step of b) is carried out under vacuum (>100 mbar); and / or(2) the hydrolyzing step of c) comprises the addition of water, sodium hydroxide and an organic solvent according to claim 4, wherein it is preferably carried out at a temperature of from 80 to 100 °C, more preferably about 85 °C to about 90 °C; and / or(3) in step d), the organic phase is washed with water at 80 °C to 100 °C, preferably about 90 °C, and / or drying is carried out by distillation, preferably azeotropic distillation under vacuum.

7. The process according to any one of the preceding claims, wherein(1) the heating of step e) is to temperatures of 130 °C to 160 °C, preferably 140 °C to 155 °C, more preferably about 143 °C to about 150 °C; and / or(2) the crystallization of step f) comprises cooling to 30 °C to 50 °C, preferably to about 40 °C.

8. The process according to any one of the preceding claims, wherein in step g) the drying is carried out by distillation, preferably under vacuum, optionally at 90 °C to 140 °C, preferably at 90 °C to 110 °C, more preferably at about 100 °C.

9. The process according to any one of the preceding claims, wherein in step h)(1) the activated carbon is a mixture of activated carbon and bentonite; and / or(2) the suitable organic solvent is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and mixtures thereof, preferably selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, fluorene, and mixtures thereof, and most preferably it is xylene; and / or(3) the elevated temperature is from 130 °C to 160 °C, preferably 140 °C to 155 °C, more preferably about 150 °C; and / or(4) removing of the activated carbon comprises filtration, preferably at 130 °C to 160 °C, more preferably at 140 °C to 155 °C, most preferably at about 150 °C; and / or(5) crystallization comprises cooling to 30 °C to 50 °C, preferably about 40 °C; and / or(6) isolation comprises filtration; and / or(7) drying is carried out under vacuum, preferably at 90 °C to 110 °C, more preferably about 100 °C.

10. The process according to any one of the preceding claims, comprising the steps ofa) reacting 2,4,6-trichloro-1 ,3,5-triazin (cyanuric chloride) with biphenyl in a suitable organic solvent, preferably heptane, at elevated temperature, preferably 100 °C to 120 °C, in the presence of a catalyst, preferably AlCh;b) removing the organic solvent after the reaction is completed, preferably by distillation under vacuum (>100 mbar);c) hydrolyzing the reaction mixture obtained in step b) by the addition of water, sodium hydroxide and a suitable organic solvent, preferably xylene, preferably at a temperature of 80 °C to 100 °C;d) separating, washing, preferably with water, and drying the organic phase obtained in step c), preferably at a temperature of 80 °C to 100 °C, more preferably by distillation under vacuum; d1) adjusting the pH of the organic phase obtained in step d) to 1.5 to 4.0, preferably 2.5 to 3.5, more preferably about 3.0, prior to drying by addition of a suitable base, preferably sodium hydroxide;e) heating the organic phase obtained in step d), preferably to a temperature of 130 °C to 160 °C, to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof; f) crystallizing the TBPT from the solution obtained in step e) by cooling, preferably to 30 °C to 50 °C;g) isolating the crystallized TBPT obtained in step f), preferably by filtration, followed by washing with a suitable organic solvent, preferably xylene, and drying, preferably by distillation under vacuum, more preferably at 90 °C to 140 °C,wherein the process optionally further comprises the step of:h) dissolving the TBPT obtained in step g) in a suitable organic solvent, preferably xylene, at elevated temperature, preferably 130 °C to 160 °C, in the presence of activated carbon and optionally bentonite, removing the activated carbon and the optional bentonite, preferably by filtration, more preferably at 130 °C to 160 °C, crystallizing the TBPT from the obtained filtrate, preferably by cooling to 30 °C to 50 °C, isolating the obtained TBPT, preferably by filtration, washing the TBPT with a suitable organic solvent, preferably isopropanol, and drying the obtained TBPT, preferably by distillation under vacuum, more preferably at 90 °C to 110 °C.

11. The process according to any one of claims 1 to 10, comprising the steps ofa) reacting 2,4,6-trichloro-1 ,3,5-triazin (cyanuric chloride) with biphenyl in a suitable organic solvent, preferably heptane, at elevated temperature, preferably 100 °C to 120 °C, in the presence of a catalyst, preferably AlCh;b) removing the organic solvent after the reaction is completed, preferably by distillation under vacuum (>100 mbar);c) hydrolyzing the reaction mixture obtained in step b) by the addition of water, sodium hydroxide and a suitable organic solvent, preferably xylene, preferably at a temperature of 80 °C to 100 °C;d) separating, washing, preferably with water, and drying the organic phase obtained in step c), preferably at a temperature of 80 °C to 100 °C, more preferably by distillation under vacuum; e) heating the organic phase obtained in step d), preferably to a temperature of 130 °C to 160 °C, to dissolve TBPT and obtain a solution of TBPT and, optionally, hot filtration thereof; f) crystallizing the TBPT from the solution obtained in step e) by cooling, preferably to 30 °C to 50 °C;g) isolating the crystallized TBPT obtained in step f), preferably by filtration, followed by washing with a suitable organic solvent, preferably xylene, and drying, preferably by distillation under vacuum, more preferably at 90 °C to 140 °C; andh) dissolving the TBPT obtained in step g) in a suitable organic solvent, preferably xylene, at elevated temperature, preferably 130 °C to 160 °C, in the presence of activated carbon and optionally bentonite, removing the activated carbon and the optional bentonite, preferably by filtration, more preferably at 130 °C to 160 °C, crystallizing the TBPT from the obtained filtrate, preferably by cooling to 30 °C to 50 °C, isolating the obtained TBPT, preferably by filtration, washing the TBPT with a suitable organic solvent, preferably isopropanol, and drying the obtained TBPT, preferably by distillation under vacuum, more preferably at 90 °C to 110 °C.

12. The process according to any one of the preceding claims, wherein the 1 ,3,5-triazine, 2,4,6-tris[1 ,1 biphenyl]-4-yl (TBPT) obtained from any one of claims 1 to 11 is further purified, wherein the further purification process comprises:A) providing the obtained TBPT according to any one of claims 1 to 11 , wherein said TBPT may comprise at least a first impurity consisting of one or more halogen-comprising triazine, and a second impurity consisting of biphenyl;B) suspending TBPT in a solvent (S1), preferably isopropyl palmitate, thereby providing a first suspension;C) heating the first suspension to a temperature of more than 200 °C, preferably more than 210 °C, more preferably about 220 °C, preferably under vacuum, thereby providing a heated first suspension or a first solution of TBPT in the solvent (S1);D) maintaining the heated first suspension or first solution of TBPT at a temperature between 100 °C and 235 °C, preferably 150 to 230 °C, more preferably 200 to 230 °C, most preferably about 223 °C, and a pressure of from 5 mbar to standard pressure, preferably from 900 mbar to standard pressure;E) cooling the heated first suspension or the first solution to a temperature of 40 to 90 °C, preferably 50 to 80 °C, more preferably about 70 °C, to allow crystallization; andF) isolating the crystals from the solution to obtain a purified composition, preferably by filtration, washing, preferably with isopropanol, and drying.

13. The process according to claim 12, wherein(1) the halogen-comprising triazine is selected from chlorine-comprising triazines, brominecomprising triazines, and a mixture thereof, preferably it is 1 ,3,5-triazine, 2,4,6-tris(4-bromophenyl) and / or 1 ,3,5-triazine, 2,4-bis([1,1'-biphenyl]-4-yl)-6-chloro (BBCT), and most preferably it is 1,3,5- triazine, 2,4-bis([1 ,1'-biphenyl]-4-yl)-6-chloro (BBCT); and / or(2) the TBPT in step a) further comprises a third impurity, the third impurity comprising, preferably consisting of, an aromatic hydrocarbon with the exception of biphenyl, more preferably the third impurity is selected from the group consisting of monocyclic-aromatic hydrocarbons, polycyclic aromatic 25 hydrocarbons (PAH), and mixtures thereof, more preferably selected from the group consisting of alkyl-substituted benzene compounds (Cn-benzenes), condensed aromatic hydrocarbons, and mixtures thereof, more preferably selected from the group consisting of benzene, toluene, xylene, ethylbenzene, naphthalene, and mixtures thereof, and most preferably xylene.

14. The process according to any one of claims 12 and 13, wherein the solvent (S1) has a boiling point at a pressure psi of 5 mbar at a temperature TBI equal to or less than 230 °C and / or has boiling point at a pressure pB2 of 1 bar at a temperature TB2 equal to or higher than 230 °C and / or can solve from 5 wt-% to 50 wt-% TBPT with respect to the total weight of the solvent at a temperature Ts in the range of from 100 °C to 235 °C, preferably in the range of from 150 °C to 230 °C.

15. 1 ,3,5-triazine, 2,4, 6-tris[1 ,1’-biphenyl]-4-yl (TBPT) comprising less than 100 ppm metal impurities selected from aluminum, cadmium, lead, iron, cobalt, chromium, and nickel, preferably less than 70, more preferably less than 50 ppm, even more preferably less than 40 ppm, less than 30 ppm, less than 25 ppm or less than 20 ppm, wherein said amount relates to the total amount of all said metals in said preparation, and / or obtained by a process according to any one of claims 1 to 14.

16. TBPT according to claim 15, wherein(1) the total aluminum content is less than 20 or less than 15 or less than 10 ppm or less than 5 ppm;(2) the total iron content is less than 40 ppm or less than 30 ppm, preferably less than 25, less than 20 or less than 15 or less than 10 ppm or less than 5 ppm;(3) the total chromium content is less than 6 ppm, more preferably less than 5 ppm, less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm;(4) the total nickel content is less than 10 ppm preferably less than 8 ppm or less than 6 ppm, more preferably less than 5 ppm, less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm;(5) the total content of arsenic is less than 2 ppm, more preferably less than 1.5 ppm or less than 1.0 ppm, even more preferably less than 0.5 ppm;(6) the total content of cadmium is less than 4 ppm, more preferably less than 3 ppm or less than 2 ppm, even more preferably less than 1 ppm;(7) the total content of lead is less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm;(8) the total content of antimony is less than 10 ppm, more preferably less than 8 ppm or less than 5 ppm, even more preferably less than 4 ppm or less than 2 ppm or less than 1 ppm;(9) the total content of mercury is less than 2 ppm, even more preferably less than 1 ppm; and (10) the total content of cobalt is less than 6 ppm, more preferably less than 4 ppm or less than 2 ppm, even more preferably less than 1 ppm.

17. Topical product, preferably cosmetic product, comprising the TBPT according to claim 15 or 16.

18. Use of TBPT according to claim 15 or 16 as a UV filter in a topical product, preferably a cosmetic product, for protecting hair and / or skin of a subject from the damaging effects of UV radiation.

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