Process for preparation of hydroxyphenyl-1, 3, 5-triazine compounds

Abstract

The invention claimed herein relates to a process for the preparation of a hydroxyphenyl-1, 3, 5-triazine compound. In particular, the invention claimed herein relates to a process for preparing a hydroxyphenyl-1, 3, 5-triazine compound by reacting the corresponding 2-chloro-1, 3, 5-triazine compound with a phenol. The invention relates to a process for preparing a hydroxy-phenyl-1, 3, 5-triazine compound, comprising the steps of preparing a deep eutectic mixture (DEM) by mixing at least one quaternary ammonium salt and at least one phenol, and reacting at least one substituted 2-chloro-1, 3, 5-triazine compound and the deep eutectic mixture to obtain a hydroxy-phenyl-1, 3, 5-triazine compound of general formula (I). # imgabs0 #

Description

Technical Field

[0001] The invention claimed herein relates to a method for preparing a hydroxyphenyl-1,3,5-triazine compound. In particular, the invention claimed herein relates to a method for preparing a hydroxyphenyl-1,3,5-triazine compound by reacting the corresponding 2-chloro-1,3,5-triazine compound and phenol. Background Art

[0002] Hydroxyphenyl-1,3,5-triazines form a class of commercially useful compounds or intermediates. Tinuvin and Tinosorb- Compounds such as are used as UV filters, and their preparation involves hydroxyphenyl-1,3,5-triazine intermediates.

[0003] The commercial preparation of hydroxyphenyl-1,3,5-triazine compounds involves the Friedel-Crafts alkylation of the corresponding 2-chloro-1,3,5-triazine compounds with phenols.

[0004] CN105218466 describes a process for preparing 2,4,6-tris(2',4'-dihydroxyphenyl)-1,3,5-triazine, which involves the reaction of cyanuric chloride and resorcinol in an aprotic or protic solvent in the presence of a metal oxide or a supported solid acid catalyst.

[0005] However, known methods for preparing hydroxyphenyl-1,3,5-triazine compounds have disadvantages, such as the use of potentially toxic metal catalysts. The post-reaction workup procedures are cumbersome and generate hazardous effluents. Typically, the triazine starting materials have low solubility, thus requiring the use of hazardous solvents.

[0006] Therefore, the object of the invention claimed herein is to provide a method for preparing hydroxyphenyl-1,3,5-triazine compounds that overcomes one or more of the above-mentioned disadvantages. The object of the invention claimed herein is to provide a method involving a non-metallic catalyst for the reaction. In addition, the object of the invention claimed herein is to provide a method involving an easy post-processing procedure. Summary of the invention

[0007] Surprisingly, it has been found that the invention claimed herein provides a process for preparing hydroxyphenyl-1,3,5-triazine compounds that overcomes one or more of the above-mentioned disadvantages. In particular, the Friedel-Crafts alkylation of the corresponding 2-chloro-1,3,5-triazine compound and phenol is carried out in the presence of a non-metallic catalyst and the work-up procedure is simple.

[0008] Thus, one aspect of the invention claimed herein is a process for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (I)

[0009]

[0010] in

[0011] Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A),

[0012]

[0013] in

[0014] R 1 To R 4 independently selected from hydrogen, -OH, -CN, -COOH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C 24 Aralkyl, -OR 5 、-COOR 5 、-NR 5 R 6 , or -C(=O)NR 5 R 6 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 Alkyl, and R 6 is a linear or branched substituted or unsubstituted C1-C 18 alkyl.

[0015] The method comprises the following steps

[0016] a) preparing a deep eutectic mixture (DEM) (IV) by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III),

[0017]

[0018] Where R 11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 18Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl, or

[0019] R 11 and R 12 Together with the nitrogen atom to which they are bound, they form a substituted or unsubstituted saturated or unsaturated 5- to 12-membered cycloalkyl ring which optionally contains 1, 2 or 3 heteroatoms selected from O, N or S as ring members; and An - is selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, alkylsulfate or carboxylate, and R 1 To R 4 As defined above; and

[0020] b) reacting at least one substituted 2-chloro-1,3,5-triazine compound of the general formula (V) and the deep eutectic mixture obtained according to step (a) to obtain a hydroxyphenyl-1,3,5-triazine compound of the general formula (I),

[0021]

[0022] in

[0023] X is chlorine or Ar 1 , and Y is chlorine or Ar 2 . DETAILED DESCRIPTION

[0024] Before describing the present compositions and formulations of the invention claimed herein, it should be understood that the invention is not limited to the specific compositions and formulations described, as such compositions and formulations may, of course, vary. It should also be understood that the terminology used herein is not intended to be limiting, as the scope of the invention claimed herein will be limited only by the appended claims.

[0025] If a group is defined as including at least a certain number of embodiments hereinafter, this means that it also includes a group preferably consisting only of these embodiments. In addition, the terms 'first', 'second', 'third' or 'a', 'b', 'c', etc. in the specification and claims are used to distinguish between similar elements, and are not necessarily used to describe sequential or chronological order. It should be understood that the terms used in this way are interchangeable where appropriate, and the embodiments of the invention claimed herein described herein can operate in other sequences except as described or shown herein. In the case of the steps of the methods or purposes or tests, the terms 'first', 'second', 'third' or '(A)', '(B)' and '(C)' or '(a)', '(b)', '(c)', '(d)', 'i', 'ii', etc., unless otherwise indicated in the application as described above or below, there is no time or time interval coherence between these steps, that is, these steps can be performed simultaneously or there can be a time interval of seconds, minutes, hours, days, weeks, months or even years between such steps.

[0026] Furthermore, ranges defined throughout this specification also include the endpoints, ie, a range of 1 to 10 means that both 1 and 10 are included in the range. For the avoidance of doubt, the applicant is entitled to any equivalents under applicable law.

[0027] In the following paragraphs, different aspects of the invention claimed herein are defined in more detail. Unless explicitly indicated to the contrary, each aspect so defined may be combined with any one or more other aspects. In particular, any feature indicated as preferred or advantageous may be combined with any one or more other features indicated as preferred or advantageous.

[0028] References throughout this specification to 'one embodiment' or 'an embodiment' mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention claimed herein. Thus, the appearances of the phrase 'in one embodiment' or 'in an embodiment' in various places throughout this specification do not necessarily all refer to the same embodiment, but may.

[0029] Furthermore, in one or more embodiments, specific features, structures, or characteristics may be combined in any suitable manner, as will be apparent to those skilled in the art from this disclosure. Furthermore, although some embodiments described herein include some but not others that are included in other embodiments, combinations of features of different embodiments are still intended to be within the scope of the invention claimed herein and to form different embodiments, as will be understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments may be used in any combination.

[0030] The invention claimed herein uses a deep eutectic mixture (DEM) (IV) obtained by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III) for the Friedel-Crafts alkylation of 2-chloro-1,3,5-triazine compounds and phenol. The DEM acts as a non-metallic catalyst for the Friedel-Crafts alkylation. In addition, the DEM acts as a solvent for 2-chloro-1,3,5-triazine compounds having low solubility. The DEMs are characterized by low vapor pressure, and they are non-flammable and environmentally friendly solvents. In addition, the phenol present in the DEM acts as a reactant. The post-processing procedure is simple.

[0031] Thus, one aspect of the invention claimed herein relates to a process for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (I)

[0032]

[0033] in

[0034] Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A),

[0035]

[0036] in

[0037] R 1 To R 4 independently selected from hydrogen, -OH, -CN, -COOH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C 24Aralkyl, -OR 5 、-COOR 5 、-NR 5 R 6 , or -C(=O)NR 5 R 6 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 Alkyl, and R 6 is a linear or branched substituted or unsubstituted C1-C 18 alkyl.

[0038] The method comprises the following steps

[0039] a) preparing a deep eutectic mixture (DEM) (IV) by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III),

[0040]

[0041] Where R 11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 18 Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl, or

[0042] R 11 and R 12 together with the nitrogen atom to which they are bound, form a substituted or unsubstituted saturated or unsaturated 5- to 12-membered cycloalkyl ring which optionally contains 1, 2 or 3 heteroatoms selected from O, N or S as ring members; and

[0043] An - is selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, alkylsulfate or carboxylate, and R 1 To R 4 As defined above; and

[0044] b) reacting at least one substituted 2-chloro-1,3,5-triazine compound of the general formula (V) and the deep eutectic mixture obtained according to step (a) to obtain a hydroxyphenyl-1,3,5-triazine compound of the general formula (I),

[0045]

[0046] in

[0047] X is chlorine or Ar 1 , and Y is chlorine or Ar 2 .

[0048] In the context of the invention claimed herein, the term alkyl, as used herein, refers to a non-cyclic saturated aliphatic group, including a alkyl radical of the general formula C n H 2n+1 The alkyl group is a straight chain saturated hydrocarbon group represented by alkyl, wherein n is the number of carbon atoms 1, 2, 3, 4, etc. Preferably, the alkyl group refers to a straight chain unsubstituted C1 to C 24 The carbon atom is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1-ethylpropyl, 1-ethylbutyl or 2-ethylbutyl.

[0049] In the context of the invention claimed herein, the term alkenyl, as used herein, refers to a non-cyclic unsaturated aliphatic group having at least one double bond, including a group consisting of the general formula C n H 2n-1 The straight-chain olefinic unsaturated hydrocarbon group represented by , wherein n is the number of carbon atoms 1, 2, 3, 4, etc. Preferably, the olefinic group refers to a straight-chain unsubstituted C2 to C 12 a carbon atom selected from the group consisting of prop-1-enyl, prop-2-enyl, but-1-enyl, but-2-enyl, but-3-enyl, pent-1-enyl, pent-2-enyl, pent-3-enyl, pent-4-enyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, hex-4-enyl, hex-5-enyl, hept-1-enyl, hept-2-enyl, hept-3-enyl, hept-4-enyl, hept-5-enyl, -4-enyl, hept-5-enyl, hept-6-enyl, oct-1-enyl, oct-2-enyl, oct-3-enyl, oct-4-enyl, oct-5-enyl, oct-6-enyl, oct-7-enyl, non-1-enyl, non-2-enyl, non-3-enyl, non-4-enyl, non-5-enyl, non-6-enyl, non-7-enyl, non-8-enyl, dec- dec-1-enyl, dec-2-enyl, dec-3-enyl, dec-4-enyl, dec-5-enyl, dec-6-enyl, dec-7-enyl, dec-8-enyl, dec-9-enyl, undec-1-enyl, undec-2-enyl, undec-3-enyl, undec-4-enyl, undec-5-enyl, undec-6-enyl, undec-7-enyl, undec-8-enyl, undec-9-enyl, undec-10-enyl, dodec-1-enyl, dodec-2-enyl, dodec-3-enyl, dodec-4-enyl, dodec-5-enyl, dodec-6-enyl, dodec-7-enyl, dodec-8-enyl, dodec-9-enyl, dodec-10-enyl or dodec-11-enyl.

[0050] In the context of the invention claimed herein, as used herein, the term cycloalkyl refers to monocyclic and bicyclic 3- to 24-membered saturated alicyclic groups, including branched cycloalkyl saturated hydrocarbons. Preferably, cycloalkyl refers to C5 to C 10 The carbon atom is selected from cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl.

[0051] In the context of the invention claimed herein, as used herein, the term cycloalkenyl refers to monocyclic and bicyclic 3- to 10-membered unsaturated alicyclic groups having at least one double bond. Preferably, cycloalkenyl refers to C5 to C 10 a carbon atom selected from the group consisting of cyclopent-1-enyl, cyclopent-2-enyl, cyclopent-3-enyl, cyclohex-1-enyl, cyclohex-2-enyl, cyclohex-3-enyl, cyclohex-4-enyl, cyclohept-1-enyl, cyclohept-2-enyl, cyclohept-3-enyl, cyclohept-4-enyl, cyclohept-5-enyl, cyclooct-1-enyl, cyclooct-2-enyl, cyclooct-3-enyl, cyclooct-4-enyl, cyclohept-5-enyl, cyclooct-1-enyl, cyclooct-2-enyl, cyclooct-3-enyl, cyclooct-4-enyl, cyclooct-4-enyl, cyclooct-5-enyl, cyclooct-2-enyl, cyclooct-3-enyl, cyclooct-4-enyl, cyclooct-4-enyl, cyclooct-5-enyl, cyclooct-1-enyl, cyclooct-2-enyl, cyclooct-3-enyl, cyclooct-4 ... Oct-5-enyl, cyclooct-6-enyl, cyclonon-1-enyl, cyclonon-2-enyl, cyclonon-3-enyl, cyclonon-4-enyl, cyclonon-5-enyl, cyclonon-6-enyl, cyclonon-7-enyl, cyclodec-1-enyl, cyclodec-2-enyl, cyclodec-3-enyl, cyclodec-4-enyl, cyclodec-5-enyl, cyclodec-6-enyl, cyclodec-7-enyl or cyclodec-8-enyl.

[0052] In the context of the invention claimed herein, the term aryl as used herein refers to phenyl or naphthyl, preferably phenyl. The term substituted aryl refers to aryl in which some or all of the hydrogen atoms are replaced by substituents, preferably these substituents are selected from hydroxy, halogen, cyano, C1-C4-alkyl or C1-C4-alkoxy. Preferably aryl is unsubstituted or carries 1, 2 or 3 substituents.

[0053] In the context of the invention claimed herein, as used herein, the term aralkyl refers to an aryl group (such as phenyl or naphthyl) having an alkyl group. Preferably, aralkyl refers to a C7-C8 group selected from benzyl, phenylethyl or 2-phenylethyl. 24 The term substituted aralkyl refers to an aryl radical in which some or all of the hydrogen atoms are replaced by substituents, preferably these substituents are selected from hydroxy, halogen, cyano, C1-C4-alkyl or C1-C4-alkoxy. Preferably the aryl radical is unsubstituted or carries 1, 2 or 3 substituents.

[0054] In the context of the invention claimed herein, the term substituted group refers to a group in which some or all of the hydrogen atoms are replaced by substituents, preferably these substituents are selected from hydroxy, halogen, cyano, C1-C4-alkyl or C1-C4-alkoxy. The group can be alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, etc.

[0055] In the context of the invention claimed herein, the term deep eutectic mixture (DEM) as used herein refers to an emerging class of mixtures characterized by a significant depression in melting point compared to the melting points of the pure constituent components.

[0056] In a preferred embodiment, the invention claimed herein relates to a process for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (I)

[0057]

[0058] in

[0059] Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A),

[0060]

[0061] in

[0062] R 1 To R 4 independently selected from hydrogen, -OH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C 24 Aralkyl, -OR 5 , or -COOR 5 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 alkyl.

[0063] In a preferred embodiment, the invention claimed herein relates to a method for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (Im):

[0064]

[0065] in

[0066] Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A),

[0067]

[0068] in

[0069] R 1 To R 4 independently selected from hydrogen, -OH, -CN, -COOH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C 24 Aralkyl, OR 5 、COOR 5 NR 5 R 6 , or C(=O)NR 5 R 6 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 Alkyl, and R 6 is a linear or branched substituted or unsubstituted C1-C 18 alkyl.

[0070] The method comprises the following steps

[0071] a) preparing a deep eutectic mixture (DEM) (IV-m) by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III-m);

[0072]

[0073] Where R 11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 18 Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl, or

[0074] R 11 and R 12together with the nitrogen atom to which they are bound, form a substituted or unsubstituted saturated or unsaturated 5- to 12-membered cycloalkyl ring which optionally contains 1, 2 or 3 heteroatoms selected from O, N or S as ring members; and

[0075] An - is selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, alkylsulfate or carboxylate, and R 1 To R 4 As defined above; and

[0076] b) reacting at least one substituted 2-chloro-1,3,5-triazine compound of the general formula (V) and the deep eutectic mixture obtained according to step (a) to obtain a hydroxyphenyl-1,3,5-triazine compound of the general formula (Im);

[0077]

[0078] in

[0079] X is chlorine or Ar 1 , and Y is chlorine or Ar 2 .

[0080] In a more preferred embodiment, the invention claimed herein relates to a method for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (In):

[0081]

[0082] in

[0083] Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A),

[0084]

[0085] in

[0086] R 1 To R 4 independently selected from hydrogen, -OH, -CN, -COOH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C24 Aralkyl, OR 5 、COOR 5 NR 5 R 6 , or C(=O)NR 5 R 6 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 Alkyl, and R 6 is a linear or branched substituted or unsubstituted C1-C 18 alkyl.

[0087] The method comprises the following steps

[0088] a) preparing a deep eutectic mixture (DEM) (IV-n) by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III-n);

[0089]

[0090] Where R 11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 18 Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl, or

[0091] R 11 and R 12 together with the nitrogen atom to which they are bound, form a substituted or unsubstituted saturated or unsaturated 5- to 12-membered cycloalkyl ring which optionally contains 1, 2 or 3 heteroatoms selected from O, N or S as ring members; and

[0092] An - is selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, alkylsulfate or carboxylate, and R 1 To R 4 As defined above; and

[0093] b) reacting at least one substituted 2-chloro-1,3,5-triazine compound of the general formula (V) and the deep eutectic mixture obtained according to step (a) to obtain a hydroxyphenyl-1,3,5-triazine compound of the general formula (In);

[0094]

[0095] in

[0096] X is chlorine or Ar 1 , and Y is chlorine or Ar 2 .

[0097] In a preferred embodiment, the molar ratio of the at least one quaternary ammonium salt (II) to the at least one phenol (III) is in the range of 1:1 to 1:15.

[0098] In a more preferred embodiment, the molar ratio of the at least one quaternary ammonium salt (II) to the at least one phenol (III) is in the range of 1:2 to 1:10; even preferably in the range of 1:3 to 1:8; and most preferably in the range of 1:3 to 1:5.

[0099] In a particularly preferred embodiment, the molar ratio of the at least one quaternary ammonium salt (II) to the at least one phenol (III) is 1:4.

[0100] In a preferred embodiment, in step (a), the mixture comprising the at least one quaternary ammonium salt (II) and the at least one phenol (III) is heated at a temperature in the range of 20°C to 150°C for a time in the range of 5 minutes to 12 hours.

[0101] In a more preferred embodiment, in step (a), the mixture comprising the at least one quaternary ammonium salt (II) and the at least one phenol (III) is mixed at a temperature in the range of 40°C to 150°C; even more preferably at a temperature in the range of 60°C to 125°C; and most preferably at a temperature in the range of 80°C to 120°C.

[0102] In a particularly preferred embodiment, in step (a), the mixture comprising the at least one quaternary ammonium salt (II) and the at least one phenol (III) is mixed at a temperature in the range of 90°C to 110°C.

[0103] In a preferred embodiment, in step (a), the mixture comprising the at least one quaternary ammonium salt (II) and the at least one phenol (III) is mixed for a time in the range of 5 minutes to 300 minutes; more preferably 10 minutes to 240 minutes; and most preferably 15 minutes to 120 minutes.

[0104] In a preferred embodiment, step (a) is performed without using a solvent.

[0105] The at least one quaternary ammonium salt and the at least one phenol form a clear DEM (IV). This step does not require a solvent. The step of forming the DEM is carried out without using a solvent, even if either or both of (II) and (III) are solids.

[0106] Step (a) can also be carried out in a solvent selected from toluene, o-dichlorobenzene, chlorobenzene, acetonitrile, methyl ethyl ketone, methyl THF or methyl tert-butyl ether. The catalytic activity of DEM is not significantly affected by the presence of solvents.

[0107] In a preferred embodiment, R 11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 24 Alkyl; more preferably C1-C 18 Alkyl; even more preferably C1-C 12 -alkyl; and most preferably C1-C8 alkyl.

[0108] In a preferred embodiment, R 11 To R 13 independently selected from linear or branched substituted or unsubstituted C1-C 24 Alkyl; more preferably C1-C 18 Alkyl; even more preferably C1-C 12 -alkyl; and most preferably C1-C8 alkyl; and

[0109] R 14 Selected from -OH substituted straight or branched C1-C 24 Alkylene; more preferably C1-C 12 Alkylene; even more preferably C1-C6-alkylene; and most preferably C1-C4-alkylene.

[0110] In a preferred embodiment, R 11 and R 12 independently selected from linear or branched substituted or unsubstituted C1-C 24 Alkyl; more preferably C1-C 18 Alkyl; even more preferably C1-C 12 -alkyl; and most preferably C1-C8 alkyl;

[0111] R 13 Selected from substituted or unsubstituted C7-C 24 Arylalkyl; more preferably C7-C 12 alkyl; and most preferably benzyl; and

[0112] R 14 Selected from -OH substituted straight or branched C1-C 24 Alkylene; more preferably C1-C 12 even more preferably C1-C6 alkylene; and most preferably C1-C4 alkylene.

[0113] In a more preferred embodiment, R 11 To R 13 are independently selected from linear or branched substituted or unsubstituted C1-C8 alkyl, or benzyl, and

[0114] R 14 Selected from -OH substituted linear or branched C1-C8 alkylene groups.

[0115] In a preferred embodiment, R 11 and R 12 Together with the nitrogen atom to which they are bound, they form a substituted or unsubstituted saturated or unsaturated 5- to 6-membered cycloalkyl ring which optionally contains one heteroatom selected from O, N or S as a ring member;

[0116] R 13 is a linear or branched substituted or unsubstituted C1-C 24 Alkyl, and

[0117] R 14 Selected from linear or branched substituted or unsubstituted C1-C6 alkyl groups.

[0118] In a preferred embodiment, An - Selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, methylsulfate, ethylsulfate, salicylate or acetate.

[0119] In a preferred embodiment, the at least one quaternary ammonium salt of formula (II) is selected from choline chloride, choline fluoride, choline bromide, choline iodide, choline acetate, choline salicylate, tetra-n-ethylammonium chloride, tetramethylammonium chloride, tetra-n-butylammonium chloride, N,N-diethylethanolammonium chloride, N-benzyl-2-hydroxy-N,N-dimethylethylammonium chloride, N-ethyl-2-hydroxy-N,N-dimethylethylammonium chloride, 2-(chlorocarbonyloxy)-N,N,N-trimethylethylammonium chloride, N-methyl-N,N,N-trioctylammonium chloride, tris(2-hydroxyethyl)methylammonium methyl sulfate, or tributylmethylammonium methyl sulfate or cetylethylmorpholinium ethane sulfate.

[0120] In a more preferred embodiment, the at least one quaternary ammonium salt having formula (II) is choline chloride.

[0121] In a preferred embodiment, the at least one phenol having formula (III) is selected from substituted or unsubstituted phenol, resorcinol, catechol, hydroquinone, cresol, methoxyphenol, salicylic acid, α-naphthol or β-naphthol.

[0122] In a more preferred embodiment, the at least one phenol having formula (III) is resorcinol.

[0123] In a preferred embodiment, the deep eutectic mixture (IV) comprises choline chloride and resorcinol.

[0124] In a preferred embodiment, the molar ratio of choline chloride to resorcinol is in the range of 1:1 to 1:15.

[0125] In more preferred embodiments, the molar ratio of choline chloride to resorcinol is in the range of 1:3 to 1:8; even more preferably 1:3 to 1:6; and most preferably 1:4.

[0126] In a more preferred embodiment, the at least one quaternary ammonium salt having formula (II) is cetyl ethylmorpholinium ethane sulfate.

[0127] In a preferred embodiment, the substituted 2-chloro-1,3,5-triazine compound having formula (V) is selected from cyanuric chloride, 6-aryl-2,4-dichloro-1,3,5-triazine or 4,6-diaryl-2-chloro-1,3,5-triazine.

[0128] In a more preferred embodiment, the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) is cyanuric chloride.

[0129] In a preferred embodiment, the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) is a 6-aryl-2,4-dichloro-1,3,5-triazine.

[0130] In a more preferred embodiment, the at least one substituted 6-aryl-2,4-dichloro-1,3,5-triazine compound having formula (V) is 2,4-dichloro-6-(4-methoxy)phenyl-1,3,5-triazine.

[0131] In a preferred embodiment, the molar ratio of the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) to the at least one phenol (III) is in the range of 1:2 to 1:20.

[0132] In a more preferred embodiment, the molar ratio of the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) to the at least one phenol (III) is in the range of 1:2 to 1:15; even more preferably in the range of 1:2 to 1:10; and most preferably 1:2 and 1:6.

[0133] In a preferred embodiment, the weight ratio of the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) to DEM (IV) is in the range of 1:2 to 1:10.

[0134] In a more preferred embodiment, the weight ratio of the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) to DEM (IV) is in the range of 1:2 to 1:8.

[0135] In a particularly preferred embodiment, the weight ratio of the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) to DEM (IV) is 1:4.

[0136] In a preferred embodiment, step (b) involves the step of adding the at least one substituted 2-chloro-1,3,5-triazine compound of general formula (V) to DES (IV) at a temperature in the range of 30°C to 150°C for a period in the range of 5 minutes to 12 hours.

[0137] In a more preferred embodiment, the addition of the at least one substituted 2-chloro-1,3,5-triazine compound having the general formula (V) to DES (IV) is carried out at a temperature ranging from 50°C to 125°C; and most preferably from 80°C to 115°C.

[0138] In a more preferred embodiment, the addition of the at least one substituted 2-chloro-1,3,5-triazine compound having the general formula (V) to the DES (IV) is carried out within a time period ranging from 5 minutes to 600 minutes; even more preferably from 15 minutes to 300 minutes; and most preferably from 15 minutes to 120 minutes.

[0139] In a preferred embodiment, in step (b), the reaction mixture obtained upon complete addition of the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) to DES (IV) is heated at a temperature in the range of 30°C to 150°C for 5 to 300 minutes.

[0140] In a more preferred embodiment, in step (b), the reaction mixture is heated at a temperature in the range of 50°C to 130°C; and most preferably 80°C to 120°C.

[0141] In a more preferred embodiment, in step (b), the reaction mixture is heated for 10 minutes to 180 minutes; and most preferably 10 minutes to 120 minutes.

[0142] In a preferred embodiment, step (b) is performed without using a solvent.

[0143] The starting material 2-chloro-1,3,5-triazine compound having the general formula (V) and the product hydroxyphenyl-1,3,5-triazine compound having the formula (I) have low solubility. DEM (IV) acts as a solvent for both the starting material and the product. Therefore, step (b) does not require a solvent.

[0144] Step (b) can also be carried out in a solvent selected from toluene, o-dichlorobenzene, chlorobenzene, acetonitrile, methyl ethyl ketone, methyl THF or methyl tert-butyl ether.

[0145] In a preferred embodiment, the hydroxyphenyl-1,3,5-triazine compound having formula (I) is

[0146]

[0147] In a preferred embodiment, the hydroxyphenyl-1,3,5-triazine compound having formula (I) is 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI)

[0148]

[0149] In a preferred embodiment, the hydroxyphenyl-1,3,5-triazine compound having formula (I) is

[0150]

[0151] In a preferred embodiment, the hydroxyphenyl-1,3,5-triazine compound having formula (I) is 2-(4-methoxyphenyl)-4,6-bis-(2,4-dihydroxyphenyl)-1,3,5-triazine (VII)

[0152]

[0153] In a preferred embodiment, the method of the present invention further comprises the step of quenching the reaction by adding water to the reaction mixture.

[0154] In a preferred embodiment, the process comprises separating the aqueous phase comprising the at least one quaternary ammonium salt of formula (II) and the at least one phenol of formula (III).

[0155] In a preferred embodiment, the process comprises recovering the at least one phenol having formula (III) from the aqueous phase.

[0156] In a more preferred embodiment, the at least one phenol having formula (III) is recovered from the aqueous phase by using at least one technique selected from evaporation of water or extraction of the aqueous phase with an organic solvent.

[0157] In a most preferred embodiment, the at least one phenol having formula (III) is recovered from the aqueous phase by extracting the aqueous phase with methyl-THF.

[0158] It was found that the recovered phenol can be reused for the preparation of DEM(IV) without losing the activity of DEM(IV).

[0159] In preferred embodiments, the at least one phenol having formula (III) comprises recovered at least one phenol having formula (III).

[0160] In a preferred embodiment, the yield of the hydroxyphenyl-1,3,5-triazine compound having formula (I) is in the range of 40 to 80 wt %; more preferably 45 to 70 wt %; and most preferably 50 to 60 wt %.

[0161] In a preferred embodiment, the purity of the hydroxyphenyl-1,3,5-triazine compound having formula (I) is in the range of 80% to 99.9%.

[0162] In a preferred embodiment, the selectivity of the hydroxyphenyl-1,3,5-triazine compound having formula (I) is in the range of 60% to 90%.

[0163] Another aspect of the invention claimed herein relates to the use of the hydroxyphenyl-1,3,5-triazine compound having formula (I) obtained by the process of the present invention for the preparation of 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-isooctyloxycarbonylethyleneoxyphenyl)triazine and bis-ethylhexyloxyphenolmethoxyphenyltriazine.

[0164] The process of the invention claimed herein has high space-time and volumetric yields due to one or more of the following reasons:

[0165] (i) The process is carried out without using a solvent and the reaction mixture comprises reactants and a quaternary ammonium salt. Therefore, the space requirement of the reaction is low.

[0166] (ii) The work-up is easy and involves a simple step of adding water to the reaction mixture followed by stirring.

[0167] (iii) The method is rapid in both steps, with low reaction time.

[0168] The invention claimed herein provides one or more of the following advantages:

[0169] 1) DEM acts as a non-metallic catalyst for the Friedel-Crafts alkylation of 2-chloro-1,3,5-triazine compounds of the general formula (V) and at least one phenol of the general formula (III).

[0170] 2) DEM acts as a green solvent for the reaction. Therefore, the Friedel-Crafts alkylation of (V) and (III) can be carried out without the use of solvent.

[0171] 3) The method of the present invention involves easy quenching and post-treatment procedures.

[0172] 4) The method of the present invention has high space-time yield and volume yield.

[0173] 5) The process of the present invention involves recovery of phenol, which can be reused.

[0174] 6) The method of the present invention is economical.

[0175] In the following, a list of examples is provided to further illustrate the present disclosure without intending to limit the present disclosure to the specific examples listed below.

[0176] 1. A method for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (I)

[0177]

[0178] in

[0179] Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A),

[0180]

[0181] in

[0182] R 1 To R 4 independently selected from hydrogen, -OH, -CN, -COOH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C 24 Aralkyl, OR 5 、COOR 5 NR 5 R 6 , or C(=O)NR 5 R 6 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 Alkyl, and R 6 is a linear or branched substituted or unsubstituted C1-C 18 alkyl,

[0183] The method comprises the following steps

[0184] a) preparing a deep eutectic mixture (DEM) (IV) by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III);

[0185]

[0186] Where R11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 18 Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl, or

[0187] R 11 and R 12 together with the nitrogen atom to which they are bound, form a substituted or unsubstituted saturated or unsaturated 5- to 12-membered cycloalkyl ring which optionally contains 1, 2 or 3 heteroatoms selected from O, N or S as ring members; and

[0188] An - is selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, alkylsulfate or carboxylate, and R 1 To R 4 As defined above; and

[0189] b) reacting at least one substituted 2-chloro-1,3,5-triazine compound of the general formula (V) and the deep eutectic mixture obtained according to step (a) to obtain a hydroxyphenyl-1,3,5-triazine compound of the general formula (I);

[0190]

[0191] in

[0192] X is chlorine or Ar 1 , and Y is chlorine or Ar 2 .

[0193] 2. The method according to embodiment 1, wherein the molar ratio of the at least one quaternary ammonium salt (II) to the at least one phenol (III) is in the range of 1:1 to 1:15.

[0194] 3. The method according to embodiment 1 or 2, wherein, in step (a), the mixture comprising the at least one quaternary ammonium salt (II) and the at least one phenol (III) is mixed at a temperature in the range of 20°C to 150°C for a time in the range of 5 minutes to 12 hours.

[0195] 4. The method of any one of embodiments 1 to 3, wherein step (a) is performed without using a solvent.

[0196] 5. The method according to any one of embodiments 1 to 3, wherein step (a) is carried out in a solvent selected from toluene, o-dichlorobenzene, chlorobenzene, acetonitrile, methyl ethyl ketone, methyl THF or methyl tert-butyl ether.

[0197] 6. The method according to any one of embodiments 1 to 5, wherein R11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 24 Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl.

[0198] 7. The method according to any one of embodiments 1 to 6, wherein:

[0199] R 11 To R 13 independently selected from linear or branched substituted or unsubstituted C1-C8 alkyl, or substituted or unsubstituted C7-C 10 aralkyl, and

[0200] R 14 Selected from -OH substituted linear or branched C1-C8 alkylene groups.

[0201] 8. The method of any one of embodiments 1 to 6, wherein:

[0202] R 11 and R 12 together with the nitrogen atom to which they are bound, form a substituted or unsubstituted saturated or unsaturated 5- to 6-membered cycloalkyl ring which optionally contains one heteroatom selected from O, N or S as a ring member,

[0203] R 13 is a linear or branched substituted or unsubstituted C1-C 24 Alkyl, and

[0204] R 14 Selected from linear or branched substituted or unsubstituted C1-C6 alkyl groups.

[0205] 9. The method according to any one of claims 1 to 6, wherein An - Selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, methylsulfate, ethylsulfate, salicylate or acetate.

[0206] 10. The method of any one of embodiments 1 to 8, wherein the at least one quaternary ammonium salt of formula (II) is selected from choline chloride, choline fluoride, choline bromide, choline iodide, choline acetate, choline salicylate, tetra-n-ethylammonium chloride, tetramethylammonium chloride, tetra-n-butylammonium chloride, N,N-diethylethanolammonium chloride, N-benzyl-2-hydroxy-N,N-dimethylethylammonium chloride, N-ethyl-2-hydroxy-N,N-dimethylethylammonium chloride, 2-(chlorocarbonyloxy)-N,N,N-trimethylethylammonium chloride, N-methyl-N,N,N-trioctylammonium chloride, tris(2-hydroxyethyl)methylammonium methyl sulfate, or tributylmethylammonium methyl sulfate or cetylethylmorpholinium ethane sulfate.

[0207] 11. The method of any one of embodiments 1 to 9, wherein the at least one quaternary ammonium salt of formula (II) is choline chloride.

[0208] 12. The method of any one of embodiments 1 to 10, wherein the at least one phenol of formula (III) is selected from substituted or unsubstituted phenol, resorcinol, catechol, hydroquinone, cresol, methoxyphenol, salicylic acid, α-naphthol or β-naphthol.

[0209] 13. The method according to any one of embodiments 1 to 11, wherein the deep eutectic mixture (IV) comprises choline chloride and resorcinol.

[0210] 14. The method of embodiment 12, wherein the molar ratio of choline chloride to resorcinol is in the range of 1:1 to 1:15.

[0211] 15. The method of embodiment 11 or 12, wherein the molar ratio of choline chloride to resorcinol is in the range of 1:3 to 1:6.

[0212] 16. The method of any one of embodiments 11 to 13, wherein the molar ratio of choline chloride to resorcinol is 1:4.

[0213] 17. The method of any one of embodiments 1 to 16, wherein the substituted 2-chloro-1,3,5-triazine compound of formula (V) is selected from cyanuric chloride, 6-aryl-2,4-dichloro-1,3,5-triazine, or 4,6-diaryl-2-chloro-1,3,5-triazine.

[0214] 18. The method of any one of embodiments 1 to 17, wherein the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) is cyanuric chloride.

[0215] 19. The method of any one of embodiments 1 to 17, wherein the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) is a 6-aryl-2,4-dichloro-1,3,5-triazine.

[0216] 20. The method of embodiment 19, wherein the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) is 2,4-dichloro-6-(4-methoxy)phenyl-1,3,5-triazine.

[0217] 21. The method of any one of embodiments 1 to 20, wherein the molar ratio of the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) to the at least one phenol (III) is in the range of 1:2 to 1:20.

[0218] 22. The method of embodiment 21, wherein the molar ratio of the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) to the at least one phenol (III) is in the range of 1:2 to 1:15.

[0219] 23. The method according to any one of embodiments 1 to 22, wherein step (b) involves the step of adding the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) to DES (IV) at a temperature in the range of 30°C to 150°C for a period of time in the range of 5 minutes to 12 hours.

[0220] 24. The process according to any one of embodiments 1 to 23, wherein in step (b), the reaction mixture obtained upon complete addition of the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) to DES (IV) is heated at a temperature in the range of 30°C to 150°C for 5 minutes to 600 minutes.

[0221] 25. The method of any one of embodiments 1 to 24 wherein step (b) is performed without the use of a solvent.

[0222] 26. The method of any one of embodiments 1 to 24, wherein step (b) is carried out in a solvent selected from toluene, o-dichlorobenzene, chlorobenzene, acetonitrile, methyl ethyl ketone, methyl THF, or methyl tert-butyl ether.

[0223] 27. The method of any one of embodiments 1 to 26, wherein the hydroxyphenyl-1,3,5-triazine compound of formula (I) is

[0224]

[0225] 28. The method of embodiment 27, wherein the hydroxyphenyl-1,3,5-triazine compound having formula (I) is 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI)

[0226]

[0227] 29. The method of any one of embodiments 1 to 26, wherein the hydroxyphenyl-1,3,5-triazine compound of formula (I) is

[0228]

[0229] 30. The method of embodiment 29, wherein the hydroxyphenyl-1,3,5-triazine compound of formula (I) is 2-(4-methoxyphenyl)-4,6-bis-(2,4-dihydroxyphenyl)-1,3,5-triazine (VII)

[0230]

[0231] 31. The method of any one of embodiments 1 to 30, further comprising the step of quenching the reaction by adding water to the reaction mixture.

[0232] 32. The method according to embodiment 31, comprising separating the aqueous phase comprising the at least one quaternary ammonium salt of formula (II) and the at least one phenol of formula (III).

[0233] 33. The method of embodiment 32, comprising recovering the at least one phenol having formula (III) from the aqueous phase.

[0234] 34. The method of any one of embodiments 1 to 33, wherein the at least one phenol of formula (III) comprises recovered at least one phenol of formula (III).

[0235] 35. The method of any one of embodiments 1 to 34, wherein the yield of the hydroxyphenyl-1,3,5-triazine compound of formula (I) is in the range of 40 to 80 wt.%.

[0236] 36. The method of any one of embodiments 1 to 35, wherein the purity of the hydroxyphenyl-1,3,5-triazine compound of formula (I) is in the range of 80% to 99.9%.

[0237] 37. The process of any one of embodiments 1 to 36, wherein the selectivity of the hydroxyphenyl-1,3,5-triazine compound of formula (I) is in the range of 60% to 90%.

[0238] 38. Use of a hydroxyphenyl-1,3,5-triazine compound of formula (I) obtained by the method according to any one of embodiments 1 to 37 for the preparation of 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-isooctyloxycarbonylethyleneoxyphenyl)triazine and bis-ethylhexyloxyphenolmethoxyphenyltriazine.

[0239] While the invention claimed herein has been described in terms of specific embodiments thereof, certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the invention claimed herein.

[0240] Examples

[0241] The invention claimed herein is illustrated in detail by the following non-limiting working examples. More particularly, the test methods specified hereinafter are part of the general disclosure of the present application and are not limited to the specific working examples.

[0242] Material

[0243] The following materials are used in the examples:

[0244] Choline chloride is available from TCI Chemicals.

[0245] Resorcinol is available from Sigma Aldrich Chemical Pvt. Ltd.

[0246] Cyanuric chloride is available from Avra ​​Synthesis Pvt. Ltd.

[0247] Dimethylformamide (DMF) was available from Spectrochem Pvt. Ltd.

[0248] Example 1: Preparation of 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI)

[0249] (Choline chloride:resorcinol molar ratio - 1:4, and cyanuric chloride:DEM weight ratio - 1:6)

[0250]

[0251]

[0252] Into a 250 mL jacketed glass reactor maintained under nitrogen atmosphere were charged choline chloride 7.2 g (51.6 mmol) and resorcinol 22.8 g (207.1 mmol), and the mixture was heated at 95°C for 30 minutes to obtain a clear solution of DEM.

[0253] Cyanuric chloride 5.0 g (27.1 mol) was slowly added to the reactor over a period of 120 minutes while maintaining the temperature of the reaction mixture at 110° C. After the addition was complete, the reaction mixture was stirred at 110° C. for 240 minutes and then cooled to 50° C.

[0254] Water (200 g) was slowly added to the reaction mass to obtain a suspension containing a yellow precipitate. The suspension was stirred at 23 °C for 30 minutes. The suspension was filtered to obtain a filter cake and a filtrate containing an aqueous phase. The filter cake was washed with water (2 x 100 g) to obtain VI. (Weight - 8.4 g (76.36%). HPLC purity - 65.80%).

[0255] Example 2-5: Effect of the Weight Ratio of Choline Chloride to Resorcinol

[0256] 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI) was prepared at different molar ratios of choline chloride to resorcinol while maintaining a weight ratio of 2-chloro-1,3,5-triazine compound to DEM of 1:6. The experimental procedure of Example 1 was used for the experiment.

[0257] The results are summarized in Table 1.

[0258] Table 1:

[0259]

[0260] *HPLC conversion rate

[0261] The use of DEMs comprising choline chloride to resorcinol in molar ratios of 1:1 and 1:2 provided products with low yields. The use of DEMs comprising choline chloride to resorcinol in molar ratios of 1:3 or higher provided products with high yields.

[0262] Example 6: Preparation (including purification) of 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI)

[0263] (Choline chloride:resorcinol molar ratio -1:4, and cyanuric chloride:DEM weight ratio -1:4)

[0264] Into a 500 mL jacketed glass reactor maintained under nitrogen atmosphere were charged choline chloride 19.0 g (143.2 mmol) and resorcinol 61.0 g (544.9 mmol), and the mixture was heated at 95°C for 30 minutes to obtain a clear solution of DEM.

[0265] Cyanuric chloride 20.0 g (108.4 mol) was slowly added to the reactor over a period of 120 minutes while maintaining the temperature of the reaction mixture at 110° C. After the addition was complete, the reaction mixture was stirred at 110° C. for 240 minutes and then cooled to 50° C.

[0266] Water (200 g) was slowly added to the reaction mass to obtain a suspension containing a yellow precipitate. The suspension was stirred at 23 °C for 40 minutes. The suspension was filtered to obtain a filter cake and a filtrate containing an aqueous phase. The filter cake was washed with water (2 x 100 g) to obtain a wet cake containing VI.

[0267] The wet cake was transferred to a 1 L container followed by the addition of 200 ml of DMF. The contents were stirred at 100° C. for 60 minutes and gradually cooled to 10° C. followed by stirring for 40 minutes to complete the precipitation. The suspension was filtered to obtain a yellow solid which was washed with cold methanol (100 ml). The product was dried at 75° C. under reduced pressure to obtain VI (weight—24 g (54.5%)).

[0268] HPLC purity: 97%

[0269] Selectivity: 70.4% (by HPLC)

[0270] 1 H-NMR (500MHz, d6-DMSO): δ12.89(s,3H),10.47(s,3H),8.10(d,3H),6.53(dd,6H),6.41(d,3H)

[0271] 13 C-NMR (500MHz, d6-DMSO): δ168.31, 164.52, 163.82, 131.53, 109.46, 109.24, 103.74.

[0272] Example 7: Preparation (including purification) of 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI)

[0273] (Choline chloride:resorcinol molar ratio - 1:4, and cyanuric chloride:DEM weight ratio - 1:6)

[0274] The reaction was carried out using the procedure of Example 6 with a weight ratio of cyanuric acid to DEM of 1:6. The amounts of materials were as follows: choline chloride 58.0 g (415.0 mmol), resorcinol 182.0 g (165.3 mmol) and cyanuric chloride 40.0 g (216.0 mmol).

[0275] The amount of Compound VI obtained after recrystallization was 45.0 g (51.1%), and the HPLC purity was 98.5%.

[0276] Example 8-9: Effect of the molar ratio of 2-chloro-1,3,5-triazine compound to DEM

[0277] Different weight ratios of 2-chloro-1,3,5-triazine compound and DEM were used to prepare 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI) while maintaining the molar ratio of choline chloride to resorcinol at 1:4. The experiment was conducted using the experimental procedure of Example 1.

[0278] No recrystallization step was performed for Examples 8 and 9. Therefore, the filter cake obtained after washing with water was dried to obtain (VI).

[0279] The results are summarized in Table 2.

[0280] Table 2:

[0281]

[0282] *Conversion rate by HPLC

[0283] Example 8: Effect of reaction time

[0284] 2,4,6-Tris(2,4-dihydroxyphenyl)-triazine (VI) was prepared using the experimental procedure of Example 1 except that the reaction was run for 22 hours instead of 5 hours.

[0285] The yield of the crude product was 66.36% and the purity was 72.16%.

[0286] Example 9: Recovery of Resorcinol from Example 1

[0287] The filtrate comprising the aqueous phase obtained in Example 6 was subjected to recovery of resorcinol.

[0288] The filtrate was extracted with methyl-THF (2 x 200 ml). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure to obtain the product containing recovered resorcinol, weight-35 g (HPLC purity-resorcinol-76.5%) (actual yield based on assay-26.4 g).

[0289] The aqueous layer obtained after extraction with methyl-THF was concentrated under reduced pressure to obtain the product containing recovered resorcinol, weight - 17 g (water - 8.8%).

[0290] Experiment 10: Preparation of Compound (VI) using recovered resorcinol

[0291] Compound (VI) was prepared using a procedure similar to that of Experiment 1.

[0292] 26.0 g (254.3 mmol, 5.0 eq.) of the recovered resorcinol (organic extraction) from Experiment 9 was used for this experiment. The amount of choline chloride was 9.0 g (64.46 mmol, 1.3 eq.), and the amount of cyanuric chloride was 6.0 g (32.5 mmol, 1.0 eq.).

[0293] The amount of (VI) obtained was 9.0 g, yield—68.2% and HPLC purity—53.2%.

Claims

1. A method for preparing a hydroxyphenyl-1,3,5-triazine compound having the general formula (I) in Ar 1 and Ar 2 are the same or different and are independently selected from substituted or unsubstituted C6-C 18 Aryl, or a moiety having formula (A), in R 1 To R 4 independently selected from hydrogen, -OH, -CN, -COOH, substituted or unsubstituted straight or branched C1-C 24 Alkyl, substituted or unsubstituted straight chain or branched C2-C 24 Alkenyl, substituted or unsubstituted C5-C 24 Cycloalkyl, substituted or unsubstituted C5-C 24 Cycloalkenyl, substituted or unsubstituted C6-C 24 Aryl, substituted or unsubstituted C7-C 24 Aralkyl, OR 5 、COOR 5 NR 5 R 6 , or C(=O)NR 5 R 6 , where R 5 is a linear or branched substituted or unsubstituted C1-C 18 Alkyl, and R 6 is a linear or branched substituted or unsubstituted C1-C 18 alkyl, The method comprises the following steps a) preparing a deep eutectic mixture (DEM) (IV) by mixing at least one quaternary ammonium salt of the general formula (II) and at least one phenol of the general formula (III), Where R 11 To R 14 independently selected from linear or branched substituted or unsubstituted C1-C 18 Alkyl, or substituted or unsubstituted C7-C 24 Aralkyl, or R 11 and R 12 together with the nitrogen atom to which they are bound, form a substituted or unsubstituted saturated or unsaturated 5- to 12-membered cycloalkyl ring which optionally contains 1, 2 or 3 heteroatoms selected from O, N or S as ring members; and An - is selected from chloride, bromide, iodide, fluoride, sulfate, sulfonate, alkylsulfate or carboxylate, and R 1 To R 4 As defined above; and b) reacting at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) and the deep eutectic mixture obtained according to step (a) to obtain the hydroxyphenyl-1,3,5-triazine compound of formula (I), in X is chlorine or Ar 1 , and Y is chlorine or Ar 2 .

2. The method according to claim 1, wherein: The molar ratio of the at least one quaternary ammonium salt (II) to the at least one phenol (III) is in the range of 1:1 to 1:

15.

3. The method according to claim 1 or 2, wherein: In step (a), the mixture comprising the at least one quaternary ammonium salt (II) and the at least one phenol (III) is mixed at a temperature in the range of 20°C to 150°C for a time in the range of 5 minutes to 12 hours.

4. The method according to any one of claims 1 to 3, wherein: Step (a) is carried out without using a solvent.

5. The method according to any one of claims 1 to 4, wherein: The at least one quaternary ammonium salt of formula (II) is selected from choline chloride, choline fluoride, choline bromide, choline iodide, choline acetate, choline salicylate, tetra-n-ethylammonium chloride, tetramethylammonium chloride, tetra-n-butylammonium chloride, N,N-diethylethanolammonium chloride, N-benzyl-2-hydroxy-N,N-dimethylethylammonium chloride, N-ethyl-2-hydroxy-N,N-dimethylethylammonium chloride, 2-(chlorocarbonyloxy)-N,N,N-trimethylethylammonium chloride, N-methyl-N,N,N-trioctylammonium chloride, tris(2-hydroxyethyl)methylammonium methyl sulfate, tributylmethylammonium methyl sulfate or cetylethylmorpholinium ethane sulfate.

6. The method according to any one of claims 1 to 5, wherein: The at least one quaternary ammonium salt having formula (II) is choline chloride.

7. The method according to any one of claims 1 to 6, wherein: The at least one phenol having formula (III) is selected from substituted or unsubstituted phenol, resorcinol, catechol, hydroquinone, cresol, methoxyphenol, salicylic acid, α-naphthol or β-naphthol.

8. The method according to any one of claims 1 to 7, wherein: The deep eutectic mixture (IV) comprises choline chloride and resorcinol.

9. The method according to claim 8, wherein: The molar ratio of choline chloride to resorcinol is in the range of 1:1 to 1:

15.

10. The method according to any one of claims 1 to 9, wherein: The substituted 2-chloro-1,3,5-triazine compound of formula (V) is selected from cyanuric chloride, 6-aryl-2,4-dichloro-1,3,5-triazine or 4,6-diaryl-2-chloro-1,3,5-triazine.

11. The method according to any one of claims 1 to 10, wherein: The molar ratio of the at least one substituted 2-chloro-1,3,5-triazine compound having formula (V) to the at least one phenol (III) is in the range of 1:2 to 1:

20.

12. The method according to any one of claims 1 to 11, wherein: Step (b) involves the step of adding the at least one substituted 2-chloro-1,3,5-triazine compound of general formula (V) to DES (IV) at a temperature in the range of 30°C to 150°C over a period in the range of 5 minutes to 12 hours.

13. The method according to any one of claims 1 to 12, wherein: In step (b), the reaction mixture obtained upon complete addition of the at least one substituted 2-chloro-1,3,5-triazine compound of formula (V) to DES (IV) is heated at a temperature ranging from 30 to 150°C for 5 to 600 minutes.

14. The method according to any one of claims 1 to 13, wherein: Step (b) is carried out without using a solvent.

15. The method according to any one of claims 1 to 14, wherein: The hydroxyphenyl-1,3,5-triazine compound having formula (I) is 16. The method according to claim 15, wherein: The hydroxyphenyl-1,3,5-triazine compound having formula (I) is 2,4,6-tris(2,4-dihydroxyphenyl)-triazine (VI) 17. The method according to any one of claims 1 to 14, wherein: The hydroxyphenyl-1,3,5-triazine compound having formula (I) is 18. The method according to claim 17, wherein: The hydroxyphenyl-1,3,5-triazine compound having the formula (I) is 2-(4-methoxyphenyl)-4,6-bis-(2,4-dihydroxyphenyl)-1,3,5-triazine (VII) 19. The method according to any one of claims 1 to 18, further comprising the step of quenching the reaction by adding water to the reaction mixture.

20. The process according to claim 19, comprising separating the aqueous phase comprising the at least one quaternary ammonium salt of formula (II) and the at least one phenol of formula (III).

21. The process according to claim 20, comprising recovering the at least one phenol of formula (III) from the aqueous phase.

22. The method according to any one of claims 1 to 21, wherein: The at least one phenol having formula (III) comprises recovered at least one phenol having formula (III).

23. The method according to any one of claims 1 to 22, wherein: The yield of the hydroxyphenyl-1,3,5-triazine compound having formula (I) is in the range of 40 to 80 wt %, and wherein the purity of the hydroxyphenyl-1,3,5-triazine compound having formula (I) is in the range of 80 to 99.9%.

24. The method according to any one of claims 1 to 23, wherein: The selectivity of the hydroxyphenyl-1,3,5-triazine compound having the formula (I) is in the range of 60% to 90%.

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