WO2020103118A1

WO2020103118A1 - Process for producing substituted anthraquinone

Info

Publication number: WO2020103118A1
Application number: PCT/CN2018/117112
Authority: WO
Inventors: Wen-juan ZHOU; Fangzheng SU; Stéphane STREIFF
Original assignee: Solvay Sa
Priority date: 2018-11-23
Filing date: 2018-11-23
Publication date: 2020-05-28

Abstract

A process for manufacturing a compound of formula (II), said process comprising a step of reacting a compound of formula (I) in the presence of a zeolite catalyst and a solvent, (I), (II) wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇ and R₈ are independently H, halo, C₁-C₁₂ alkyl, C₁-C₁₂ alkyloxy, C₂-C₁₂ alkenyl, C₂-C₁₂ alkenyloxy, C₂-C₁₂ alkynyl, C₂-C₁₂ alkynyloxy, C₃-C₈ cycloalkyl, C₃-C₈ cycloalkyloxy, C₆-C₁₀ aryl, C₆-C₁₀ aryloxy, C₇-C₁₀ aralkyl, C₇-C₁₀ alkylaryl or C₄-C₇ heteroaryl; and wherein the solvent is a halogen substituted aromatic compound.

Description

[Title established by the ISA under Rule 37.2] PROCESS FOR PRODUCING SUBSTITUTED ANTHRAQUINONE

TECHNCIAL FIELD

The present disclosure relates to a process for producing substituted anthraquinone.

BACKGROUND

Classic production of substituted anthraquinone is realized by using large excess of oleum that is associated with waste and safety problem. Zeolites, resin and carbon materials are reported to be able to transform 2- (4’-alkylbenzoyl) benzoic acid into corresponding alkylanthraquinone. However, solvent-free cyclization reaction often leads to low efficiency and selectivity.

Process for manufacturing alkyl-anthraquinones from 2- (4’-alkylbenzoyl) benzoic acid using zeolite catalysts is well known in the field. CN107098802 A describes conversion of 2- (4’-alkylbenzoyl) benzoic acid to alkyl-anthraquinone using a zeolite catalyst and biphenyl, isopropylbiphenyl, diisopropylbiphenyl, di-Me phthalate, di-Et phthalate or di-Pr phthalate as a solvent. However, the reactions in the examples are all performed at high temperature in order to achieve high yield of alkyl-anthraquinones.

Up to now, no prior art discloses a process for manufacturing alkyl-anthraquinones from 2- (4’-alkylbenzoyl) benzoic acid wherein a halogenated aromatic solvent is used during the conversion.

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to a process for manufacturing a compound of formula (II) , said process comprising a step of reacting a compound of formula (I) in the presence of a zeolite catalyst and a solvent, wherein the solvent is a halogen substituted aromatic compound,

and wherein R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, R ₇ and R ₈ are independently H, halo, C ₁-C ₁₂ alkyl, C ₁-C ₁₂ alkyloxy, C ₂-C ₁₂ alkenyl, C ₂-C ₁₂ alkenyloxy, C ₂-C ₁₂ alkynyl, C ₂-C ₁₂ alkynyloxy, C ₃-C ₈ cycloalkyl, C ₃-C ₈ cycloalkyloxy, C ₆-C ₁₀ aryl, C ₆-C ₁₀ aryloxy, C ₇-C ₁₀ aralkyl, C ₇-C ₁₀ alkylaryl or C ₄-C ₇ heteroaryl.

DEFINITIONS

For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are collected here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

The articles “a” , “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

The term “and/or” includes the meanings “and” , “or” and also all the other possible combinations of the elements connected to this term. As disclosed herein, “and/or” means “and, or as an alternative” .

All ranges include endpoints unless otherwise indicated.

Throughout the description, including the claims, the term "comprising one" should be understood as being synonymous with the term "comprising at least one" , unless otherwise specified, and "between" should be understood as being inclusive of the limits.

It should be noted that in specifying any range of concentration, any particular upper concentration can be associated with any particular lower concentration.

It is specified that, in the continuation of the description, unless otherwise indicated, the values at the limits are included in the ranges of values which are given.

As used herein, the term "alkyl" means a saturated hydrocarbon radical, which may be straight, or branched, such as, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, t-butyl, pentyl, n-hexyl. Alkyl preferably contains 1 to 20 carbon atoms, preferably 1-12, or 1-10 carbon atoms, preferably 1-8 carbon atoms, more preferably, 1-6 carbon atoms.

As used herein, the term “alkyloxy” means alkyl-O-, wherein alkyl is as defined above.

As used herein, the term "alkenyl" as a group or part of a group denotes an aliphatic hydrocarbon group containing at least one carbon-carbon double bond and which may be straight or branched. The group may contain a plurality of double bonds in the normal chain and the orientation about each is independently E or Z. Exemplary alkenyl groups include, but are not limited to, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl and nonenyl. The group may be a terminal group or a bridging group.

As used herein, the term "alkynyl" as a group or part of a group denotes an aliphatic hydrocarbon group containing at least one carbon-carbon triple bond and which may be straight or branched. The group may contain a plurality of triple bonds in the normal chain. Exemplary alkynyl groups include, but are not limited to, ethynyl, propynyl, butynyl, pentynyl, hexynyl, and the like.

As used herein, the term "alkenyloxy" means alkenyl-O-, wherein alkenyl is as defined above.

As used herein, the term "alkynyloxy" means alkynyl-O-, wherein alkynyl is as defined above.

As used herein, the term "aryl" refers to a monovalent aromatic hydrocarbon group, including bridged ring and/or fused ring systems, containing at least one aromatic ring. Examples of aryl groups include phenyl, naphthyl and the like. The term "arylalkyl" or the term "aralkyl" refers to alkyl substituted with an aryl. The term "arylalkoxy" refers to an alkoxy substituted with aryl.

As used herein, the term "cyclic group" means a closed ring hydrocarbon group that is classified as an alicyclic group, aromatic group, or heterocyclic group. The term "alicyclic group" means a cyclic hydrocarbon group having properties resembling those of aliphatic groups.

As used herein, the term "cycloalkyl" as used herein means cycloalkyl groups containing from 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms, for example cyclohexyl.

As used herein, the term "aromatic compound" as used herein means a compound conforming to the Hückel rule, such as benzene, naphthalene and the like. The aromatic compound may be further substituted by such as hydroxy, amino, C ₁-C ₂₀ alkyl, C ₂-C ₂₀ alkenyl, C ₂-C ₂₀ alkynyl, C ₁-C ₂₀ alkyloxy, C ₂-C ₂₀ alkenyloxy, or C ₂-C ₂₀ alkynyloxy. Preferably, the aromatic compound may be further substituted by H, hydroxy, amino, C ₁-C ₆ alkyl, C ₂-C ₆ alkenyl, C ₂-C ₆ alkynyl, C ₁-C ₆ alkyloxy, C ₂-C ₆ alkenyloxy, or C ₂-C ₆ alkynyloxy.

As used herein, the terminology " (C _n-C _m) " in reference to an organic group, wherein n and m are each integers, indicates that the group may contain from n carbon atoms to m carbon atoms per group.

DETAILED DESCRIPTION OF THE INVENTION

Preferably, R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, R ₇ and R ₈ are independently H, halo, C ₁-C ₆ alkyl, C ₁-C ₆ alkyloxy, C ₂-C ₆ alkenyl, C ₂-C ₆ alkenyloxy, or C ₃-C ₈ cycloalkyl.

More preferably, R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, R ₇ and R ₈ are independently H, halo, C ₁-C ₆ alkyl, or C ₁-C ₆ alkyloxy.

Even more preferably, R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, and R ₈ are independently H, halo, C ₁-C ₆ alkyl, or C ₁-C ₆ alkyloxy, and R ₇ is C ₁-C ₆ alkyl.

Even more preferably, R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, and R ₈ are independently H, and R ₇ is C ₁-C ₆ alkyl.

Most preferably, the compound of formula (I) is 2- (4’-ethylbenzoyl) benzoic acid or 2- (4’-amylbenzoyl) benzoic acid.

Solvent

As previously expressed, the solvent is a halogen substituted aromatic compound.

As used herein, the term "halogen" refers to F, Cl, Br, and I. Preferably, the halogen substituted to benzene compound is Cl or Br.

The solvent is a halogen substituted benzene compound, or a halogen substituted naphthalene compound, preferably chloro substituted benzene compound or bromo substituted benzene compound.

Preferably, the solvent is benzene substituted by at least two halogen atoms and more preferably 2 to 4 halogen atoms. Examples of such solvent are benzene substituted by 2, 3 or 4 chlorine atoms or benzene substituted by 2, 3 or 4 bromine atoms.

More preferably, the solvent may be selected from the group consisting of 1, 2-dichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 2, 4, 5-tetrachlorobenzene.

The solvent may be used at an amount of 2 mL to 100 mL solvent per gram of the compound of formula (I) .

Zeolite catalyst

The zeolite catalyst is not particularly limited. All the zeolites having catalytic activity towards the reaction according to the present invention can be used. Notably, the zeolite catalyst can be MOR, BEA, MFI, FAU or FER framework. MOR, MFI, BEA, FAU and FER framework are all the framework type codes assigned by International Zeolite Association (IZA) structure commission, which is authorized by IUPAC.

The zeolite catalyst may be H-MOR, H-BEA, H-MFI, H-FAU or H-FER; it preferably is H-MOR or H-BEA.

Preferably, the weight ratio of the compound of formula (I) to zeolite may be 10: 1 to 1: 1, preferably 5: 1 to 2: 1.

Additive

The process can be carried out in the presence of a zeolite catalyst, a solvent and a nucleophilic reagent.

The nucleophilic reagent can be a pyridine, substituted pyridine, pyrimidine and/or substituted pyrimidine. Substituted pyridine or pyrimidine refers to pyridine or pyrimidine which is substituted by one or more C ₁-C ₂₀ alkyl, preferably C ₁-C ₁₀ alkyl, more preferably C ₁-C ₆ alkyl. For example, the substituted pyridine or pyrimidine can be 2, 6-di-tert-butyl-4-methylpyridine, 2, 4, 6-tri-tert-butyl-pyridine or 2, 4, 6-tri-tert-butylpyrimidine.

Alternatively, the nucleophilic reagent can be a phosphine compound of formula PR ¹R ²R ³ or an amine compound of formula NR ¹R ²R ³, wherein R ¹, R ² an R ³ are independently selected from the group of H, C ₁-C ₂₀ alkyl, C ₂-C ₂₀ alkenyl, C ₂-C ₂₀ alkynyl, C ₆-C ₂₀ aryl, C ₇-C ₂₀ alkylaryl, and C _7-C ₂₀ arylalkyl, preferably, H, C ₁-C ₆ alkyl, C ₂-C ₆ alkenyl, C ₂-C ₆ alkynyl, C ₆-C ₁₀ aryl, C ₇-C ₁₀ alkylaryl, and C ₇-C ₁₀ arylalkyl, more preferably, R ¹, R ² an R ³ are independently selected from the group of C ₁-C ₆ alkyl and phenyl. Preferably phosphine compound of formula PR ¹R ²R ³ is triphenylphosphine. Preferably amine compound of formula NR ¹R ²R ³ is triphenylamine.

The nucleophilic reagent may be added in the amount of 0.1-100 mg per gram of the compound of formula (I) .

In some embodiments, R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, and R ₈ are independently H, and R ₇ is C ₁-C ₆ alkyl, the compound of formula (I) is reacted in the presence of a H-MOR or a H-BEA zeolite catalyst and a solvent at a temperature of 150-270 ℃, wherein the solvent is a halogen substituted aromatic compound, preferably polychlorobenzene, even preferably 1, 2-dichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 2, 4, 5-tetrachlorobenzene.

Preferably, the above process is carried out in the presence of a nucleophilic reagent.

The nucleophilic reagent can be a pyridine, substituted pyridine, pyrimidine and/or substituted pyrimidine. Substituted pyridine or pyrimidine refers to pyridine or pyrimidine which is substituted by one or more C ₁-C ₂₀ alkyl, preferably C ₁-C ₁₀ alkyl, more preferably C ₁-C ₆ alkyl. For example, the substituted pyridine can be 2, 6-di-tert-butyl-4-methylpyridine or 2, 4, 6-tri-tert-butyl-pyridine. The substituted pyrimidine can be or 2, 4, 6-tri-tert-butylpyrimidine.

Alternatively, the nucleophilic reagent can be a phosphine compound of formula PR ¹R ²R ³ or an amine compound of formula NR ¹R ²R ³, wherein R ¹, R ² an R ³ are independently selected from the group of H, C ₁-C ₂₀ alkyl, C ₂-C ₂₀ alkenyl, C ₂-C ₂₀ alkynyl, C ₆-C ₂₀ aryl, C ₇-C ₂₀ alkylaryl, C _7-C ₂₀ arylalkyl, preferably, H, C ₁-C ₆ alkyl, C ₂-C ₆ alkenyl, C ₂-C ₆ alkynyl, C ₆-C ₁₀ aryl, C ₇-C ₁₀ alkylaryl, C ₇-C ₁₀ arylalkyl, more preferably, R ¹, R ² an R ³ are independently selected from the group of C ₁-C ₆ alkyl and phenyl. Preferably phosphine compound of formula PR ¹R ²R ³ is triphenylphosphine. Preferably amine compound of formula NR ¹R ²R ³ is triphenylamine.

In every embodiment of the present application, the process may be carried out at a temperature of 150-270 ℃, preferably 160-260 ℃, more preferably 180-240 ℃.

In every embodiment of the present application, the process may be carried out for 1-10 hours, preferably 2-8 hours, more preferably 4-5 hours.

The use of a halogen substituted aromatic compound, such as polychlorobenzene, as solvent with high boiling point can greatly enhance conversion of the substrate acid and selectivity of substituted anthraquinone, in comparison with the case of solvent-free conditions.

It is also found that a halogen substituted aromatic compound, such as polychlorobenzene can increase the selectivity of substituted anthraquinone at the same reaction temperature, in comparison with the solvents used in CN 107098802. The reaction according to the present invention can achieve ideal selectivity at a lower temperature than CN 107098802. Thus, it is safer and more suitable for industrialization.

The zeolite catalyst, such as H-BEA or H-MOR, exhibits good recyclability without any loss of activity and selectivity after regeneration. The zeolite, such as H-BEA or H-MOR catalyst both show good activity and selectivity.

Examples

Some embodiments of the invention will now be described in the following Examples, wherein all parts and percentages are by weight unless otherwise specified.

Materials:

H-BEA (available from Clariant, HCZB 150)

H-MOR (available from Zeolyst, CBV21A)

Dichlorobenzene (available from J&K, 99%)

Trichlorobenzene (available from J&K, 98%)

Tetrachlorobenzene (available from J&K, 98%)

EBOB: 2- (4’-ethylbenzoyl) benzoic acid

EQ: 2-ethylanthraquinone

ABOB: 2- (4’-amylbenzoyl) benzoic acid which is a mixture of 2- (4’-sec-amylbenzoyl) benzoic acid and 2- (4’-tert-amylbenzoyl) benzoic acid

AQ: 2-sec-amylanthraquinone and 2-tert-amylanthraquinone

Procedures:

In a typical reaction, a desirable amount of catalyst, substrate, solvent (if any) and additives (if any) were added into a reactor. The reactor was then placed in a preheated oil bath at a certain temperature for a certain period of time as described in the examples. If triphenylphosphine or triphenylamine was used as additive, desirable amount of catalyst, solvent and additives were mixed for a certain time before the addition of substrate. After a certain reaction time, a certain amount of tetrahydrofuran was added and liquid sample was collected after filtration of solid. The products were analyzed by a high performance liquid chromatography (Agilent 1260) .

Example 1: Cyclization of 2- (4’-ethylbenzoyl) benzoic acid (EBOB) to corresponding ethylanthraquinone (EQ) was investigated over H-BEA zeolite and H-MOR zeolite.

Table 1

1.5 g EBOB, 0.5 g catalyst, 5h, 5 ml solvent. In case of solvent-free conditions, 3 g EBOB and 1 g catalyst were added.

From the results in Table 1, it can be seen that H-BEA zeolite, available from Clariant and labelled as HCZB150, and H-MOR zeolite, available from Zeolyst and labeled as CBV21A both showed good conversion of EBOB, high EQ selectivity and high EQ yield in cyclization of 2- (4’-ethylbenzoyl) benzoic acid to ethylanthraquinone in the presence of a polychlorobenzene as a solvent. The EBOB conversion, EQ selectivity, and EQ yield are much higher than those of solvent-fee reaction conditions.

Example 2: Cyclization of EBOB into EQ without solvent or in different solvents.

Table 2

solvent	EBOB conversion (%)	EQ selectivity (%)
solvent-free	42	31
1, 2-dichlorobenzene	84	44
1, 2, 4-trichlorobenzene	76	41
glycol	0	0
diethylene glycol diethyl ether	0	0
1, 2-propanediol	12	0
dimethyl sulfoxide	0	0
benzonitrile	87	0

Reaction conditions: 1.5 g EBOB, 5 ml solvent, 0.5 g H-BEA catalyst, 180 ℃, 5 h.

From the above results in Table 2, it can be seen that when polychlorobenzene is used as a solvent, the substrate conversion and/or product selectivity are much higher than those using glycol, diethylene glycol diethyl ether, 1, 2-propanediol, dimethyl sulfoxide and benzonitrile as a solvent and those without a solvent.

Example 3: Cyclization of 2- (4’-amylbenzoyl) benzoic acid (ABOB) into 2-amylanthraquinone (AQ) over H-BEA zeolite (HCZB150) using polychlorobenzenes as solvents.

Table 3

Cyclization of ABOB over H-BEA by using 1, 2, 4-trichlorobenzene as solvent

Reaction conditions: 0.5 g ABOB, 0.25g H-BEA, 5 ml 1, 2, 4-trichlorobenzene, 5 h.

From the above results in Table 3, it can be seen that when1, 2, 4-trichlorobenzene is used as a solvent, the substrate conversion, product selectivity and product selectivity are all increased with an increase of reaction temperature.

Example 4: Cyclization of ABOB into AQ without solvent or in different solvents

Table 4

solvent	ABOB conversion (%)	AQ selectivity (%)
solvent-free	55	35
trichlorobenzene	99	81
γ-Valerolactone	99	1
propylene carbonate	87	5
octanoic acid	45	41
diethyl phthalate	93	7.4

Reaction conditions: 0.5 g ABOB, 5 ml solvent, 0.25 g H-BEA catalyst, 215 ℃, 5 h.

From the above results in Table 4, it can be seen that H-type BEA zeolite shows good performance for cyclization of 2- (4’-amylbenzoyl) benzoic acid to give amylanthraquinone by using trichlorobenzene as a solvent. The product selectivity when trichlorobenzene is used as a solvent is much higher than that of solvent-fee reaction conditions or using other solvents such as γ-Valerolactone, propylene carbonate, octanoic acid or diethyl phthalate. When trichlorobenzene is used as a solvent, the substrate conversion is much higher than that of solvent-fee reaction condition or using other solvents such as propylene carbonate or octanoic acid.

Example 5: Preparation of AQ from ABOB in the presence of H-BEA zeolite (HCZB150) and polychlorobenzenes at different temperatures.

Table 5

Reaction conditions: 0.5 g ABOB, 0.25 g HCZB-150, 5 ml solvent, 5 h.

Example 6: Recycle test: Catalyst was separated from reactant by centrifugation, washed 3 times with ethanol, dried at 80 ℃ under vacuum overnight and calcined at 600 ℃ for 3 h.

Table 6

Reaction conditions: 5 g ABOB, 2.5 g HCZB-150, 50 ml 1, 2, 4-trichlorobenzene, 5 h, 215 ℃.

From the above results in Table 6, it can be seen that even after been used for 10 cycles, the catalyst is still effective.

Example 7: Effect of an additive, 2, 6-Di-tert-butyl-4-methylpyridine in EBOB cyclization by using HCZB150 as a catalyst.

Table 7

Reaction conditions: 0.75 g EBOB, 0.25 g HCZB-150, 5 ml 1, 2, 4-trichlorobenzene, 2, 6-Di-tert-butyl-4-methylpyridine as additive (amount is calculated based on EBOB) , 5 h, 215 ℃.

From the above results in Table 7, it can be seen that the use of a nucleophilic reagent 2, 6-Di-tert-butyl-4-methylpyridine as an additive further improves the product selectively and yield.

Example 8: Effect of different additives in ABOB cyclization by using HCZB150 as a catalyst.

Table 8

Reaction conditions: 5 g ABOB, 2.5 g HCZB-150, 50 ml 1, 2, 4-trichlorobenzene, 2, 4, 6-tri-tert-butyl-pyrimidine or triphenylphosphine as additives, 5 h, 215 ℃.

In this example, catalyst was mixed with 1, 2, 4-trichlorobenzene and triphenylphosphine for 0.5 h at 215 ℃. Then ABOB was added. After that, the reaction was run for 5 h. From the above results in Table 8, it can be seen that the use of a nucleophilic reagent triphenylphosphine or 2, 4, 6-tri-tert-butyl-pyrimidine as an additive also further improves the product selectively and yield.

Example 9: Effect of an additive, 2, 4, 6-tri-tert-butyl-pyrimidine at different HCZB150 catalyst loadings

Table 9

Reaction conditions: 0.5 g ABOB, 5 ml 1, 2, 4-trichlorobenzene, 2, 4, 6-tri-tert-butyl-pyrimidine/HCZB-150=0.05 (weight ratio) , 5 h, 215 ℃.

Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

A process for manufacturing a compound of formula (II) , said process comprising a step of reacting a compound of formula (I) in the presence of a zeolite catalyst and a solvent

wherein R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, R ₇ and R ₈ are independently H, halo, C ₁-C ₁₂ alkyl, C ₁-C ₁₂ alkyloxy, C ₂-C ₁₂ alkenyl, C ₂-C ₁₂ alkenyloxy, C ₂-C ₁₂ alkynyl, C ₂-C ₁₂ alkynyloxy, C ₃-C ₈ cycloalkyl, C ₃-C ₈ cycloalkyloxy, C ₆-C ₁₀ aryl, C ₆-C ₁₀ aryloxy , C ₇-C ₁₀ aralkyl, C ₇-C ₁₀ alkylaryl or C ₄-C ₇ heteroaryl and wherein the solvent is a halogen substituted aromatic compound.
The process of claim 1, wherein R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, and R ₈ are independently H, halo, C ₁-C ₆ alkyl, or C ₁-C ₆ alkyloxy, and R ₇ is C ₁-C ₆ alkyl.
The process of claim 2, wherein R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, and R ₈ are independently H, and R ₇ is C ₁-C ₆ alkyl.
The process of claim 3, wherein the compound of formula (I) is 2- (4’ -ethylbenzoyl) benzoic acid or 2- (4’ -amylbenzoyl) benzoic acid.
The process of any of the preceding claims, wherein the halogen substituted aromatic solvent is a halogen substituted benzene compound or a halogen substituted naphthalene compound.
The process of claim 5, wherein the halogen substituted aromatic solvent is benzene substituted by 2, 3 or 4 chlorine atoms or benzene substituted by 2, 3 or 4 bromine atoms.
The process of claim 6, wherein the halogen substituted aromatic solvent is selected from the group consisting of 1, 2-dichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 2, 4, 5-tetrachlorobenzene.
The process of any of the preceding claims, wherein the zeolite catalyst is selected from the group consisting of H-MOR and H-BEA.
The process of any of the preceding claims, wherein the weight ratio of the compound of formula (I) to zeolite is 10: 1 to 1: 1, preferably 5: 1 to 2: 1.
The process of any of the preceding claims, wherein the process is carried out in the presence of a nucleophilic reagent.
The process of claim 10, wherein the nucleophilic reagent is a pyridine, substituted pyridine, pyrimidine and/or substituted pyrimidine.
The process of claim 11, wherein substituted pyridine or pyrimidine is pyridine or pyrimidine substituted by one or more C ₁-C ₂₀ alkyl.
The process of claim 12, wherein substituted pyridine or pyrimidine is 2, 6-di-tert-butyl-4-methylpyridine, 2, 4, 6-tri-tert-butylpyridine, or 2, 4, 6-tri-tert-butylpyrimidine.
The process of claim 10, wherein the nucleophilic reagent is a phosphine compound of formula PR ¹R ²R ³ or an amine compound of formula NR ¹R ²R ³, wherein R ¹, R ² an R ³ are independently selected from the group of H, C ₁-C ₂₀ alkyl, C ₂-C ₂₀ alkenyl, C ₂-C ₂₀ alkynyl, C ₆-C ₂₀ aryl, C ₇-C ₂₀ alkylaryl, and C ₇-C ₂₀ arylalkyl.
The process of claim 14, wherein R ¹, R ² an R ³ in the phosphine compound of formula PR ¹R ²R ³ or in the amine compound of formula NR ¹R ²R ³ are independently selected from the group of C ₁-C ₆ alkyl and phenyl.
The process of claim 15, wherein the phosphine compound of formula PR ¹R ²R ³ is triphenylphosphine.
The process of claim 1, wherein the zeolite is a H-MOR or a H-BEA zeolite, wherein the reaction temperature is 150-270 ℃, and wherein R ₁, R ₂, R ₃, R ₄, R ₅, R ₆, and R ₈ are independently H, and R ₇ is C ₁-C ₆ alkyl.