JP2005145862A - Method for producing aromatic ethers - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aromatic ether having an objective structure in excellent selectivity by using a phenol and an oxirane compound as raw materials while controlling formation of by-product. <P>SOLUTION: In synthesizing an aromatic ether by reacting a phenol with an oxirane compound by using an anion exchangeable laminar compound as a catalyst, the method for producing an aromatic ether comprises using (A) a hydrotalcite-like compound obtained by decarbonating a compound having a hydrotalcite structure and an interlayer carbonate anion and introducing an anion except the carbonate anion into the compound or (B) a compound having a botallackite structure as the anion exchangeable laminar compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a corresponding aromatic ether from a phenol and an oxirane compound.

  Aromatic ethers such as β-phenoxyethanols have alcoholic hydroxyl groups in their molecules and are therefore used for various purposes. The above aromatic ethers are a kind of glycol ether and have a high boiling point, and are therefore excellent solvents in terms of working environment. Further, it is used as an important raw material for various chemicals including polyester raw materials, polyurethane raw materials, (meth) acrylate raw materials and the like by utilizing the action of alcoholic hydroxyl groups in the molecule.

  Further, when the aromatic ether also has a phenolic hydroxyl group in the molecule, it is widely used in the cosmetics field, the pharmaceutical field, and the perfume field, particularly using the bactericidal action of the phenolic hydroxyl group. For example, it has been shown to be useful as a highly safe external preparation for skin. Furthermore, it has good resolution, depth of focus and developability, and is used as a resist composition for integrated circuit fabrication having excellent sensitivity, resist pattern cross-sectional shape and storage stability, and as a cationic electrodeposition coating composition. Is also known.

  The synthesis of the above aromatic ethers has a very slow reaction rate and many side reactions without a catalyst. For this reason, the aromatic ethers are produced using a catalyst.

  For example, as a method for producing β-phenoxyethanols contained in the aromatic ethers, a method of synthesizing using an alkali metal salt and a large amount of water has been conventionally known (Patent Document 1).

  In addition, as a method for producing the aromatic ether by a non-aqueous process, a catalyst comprising a halogenated phosphonium salt or a tertiary phosphine and an alkyl halide (Patent Document 2), or a trialkylbenzylammonium halide is used. The reaction is known (Patent Document 3).

  By the way, if the catalyst remains in the aromatic ethers which are reaction products, the product (the aromatic ethers) may be adversely affected. Therefore, it is preferable to remove the catalyst after the production of the aromatic ethers.

  However, since the techniques disclosed in these patent documents 1 to 3 use a homogeneous catalyst, it is difficult to recover the catalyst after the reaction product is generated.

  For example, in addition to the techniques disclosed in Patent Documents 1 to 3, homogeneous catalysts such as metal hydroxides and ammonium salts are known as general catalysts. When these aromatic ethers are synthesized using these catalysts, the catalysts form salts with phenols that are raw materials. In order to remove this salt, complicated steps such as acid neutralization and water washing are required. Further, when acid neutralization is performed, phenols are liberated, leading to an increase in unreacted raw materials.

  It is possible to reduce the amount of free phenols at the time of neutralization by carrying out an excessive addition reaction between phenols and oxirane compounds. This causes a problem that it is difficult to obtain a product with high purity.

  Further, as a method for synthesizing the above aromatic ethers having a phenolic hydroxyl group, for example, a method of adding an oxirane compound to polyhydric phenols in the presence of a transition metal ion catalyst such as an iron ion is known ( Patent Document 4).

  However, according to the study by the present inventors, in this method, quinones are formed because a trace amount of oxygen present in the reaction system is oxidized by the transition metal ion as a catalyst to oxidize polyhydric phenol (catechol) as a raw material. It turns out that it is easy to do. Such quinones form so-called quinhydrones with phenols. Since these quinhydrones cause coloring of the aromatic ethers to be produced, the burden on the purification step after the reaction step increases, and this is not an industrially advantageous method.

  In general, quinhydrone is a molecular compound consisting of hydroquinone, which is a polyhydric phenol, and p-benzoquinone, which is an oxidation product thereof. The quinhydrone here refers to polyhydric phenols and their oxidation products. It refers to molecular compounds composed of quinones.

  Furthermore, Patent Document 5 discloses a method of adding ethylene oxide to polyhydric phenols using a halogenated quaternary ammonium compound and a halogenated quaternary phosphonium compound. However, according to the study by the present inventors, it is difficult to selectively synthesize aromatic ethers having a phenolic hydroxyl group by this method, and since the catalyst is a low molecule, the reaction crude after the reaction is completed. It was found that it was difficult to separate the catalyst from the liquid, and this was not an industrially advantageous method.

Patent Document 6 discloses a catalyst containing hydrotalcite as a catalyst for ethoxylation or propoxylation of a compound containing an active hydrogen atom, and as a compound containing an active hydrogen atom. , Alkylphenols (mono-, di- or trialkylphenols, especially those containing 4 to 12 carbon atoms in the alkyl group) are also mentioned, but specific descriptions (reactions according to specific compound names and examples of alkylphenols) There is no experiment).
Japanese Examined Patent Publication No. 39-30272 Japanese Patent Publication No. 50-654 Japanese Patent Publication No.49-33183 Dutch Patent No. 6600188 Japanese Patent Publication No.54-1291 Japanese Patent No. 3283510

  The present invention has been made in view of the above circumstances, and its purpose is to produce aromatic ethers having the desired structure with high selectivity while suppressing the production of by-products from phenols and oxirane compounds as raw materials. It is to provide a method of obtaining.

The process for producing the aromatic ether of the present invention that has achieved the above object is to use the anion exchange layered compound as a catalyst and react the phenol with an oxirane compound to synthesize the aromatic ether. A gist exists where the following compound (A) or (B) is used as the active layered compound.
(A) A hydrotalcite-like compound obtained by decarboxylating a compound having a hydrotalcite structure and having a carbonate anion between layers and introducing an anion other than the carbonate anion.
(B) A compound having a botalakite structure.

  By using these anion-exchange layered compounds as catalysts, the above-mentioned aromatic ethers can be produced with high yield by increasing the reaction activity.

  Further, the target compound (aromatic ethers) and the catalyst can be easily separated and can be used repeatedly. Since the catalyst can be easily separated, there is no need for a neutralization step of the catalyst after the reaction, and there is no increase in salts of unreacted phenols and impurities. Further, since it is possible to reduce unreacted phenols, it is not necessary to add an oxirane compound excessively, so there is little production of by-products, and the production selectivity of aromatic ethers of the target structure is good.

  According to the method of the present invention, when an aromatic ether is produced by reacting a phenol with an oxirane compound, an anion-exchange layered compound is used as a catalyst, thereby increasing the reaction activity and generating by-products. Thus, aromatic ethers having the target structure can be produced with good yield.

  The aromatic ethers obtained by the method of the present invention have a structure in which an alkylene chain having an alcoholic hydroxyl group is bonded to an aromatic ring via an ether bond, and is roughly classified into the following two modes. . First, the raw material phenols are polyhydric phenols, and after reaction with the oxirane compound, at least one hydroxyl group of the polyhydric phenols remains, that is, has a phenolic hydroxyl group. Aromatic ethers. Second, the starting phenols are unitary or polyhydric phenols, and are reacted with the oxirane compound without substantially leaving the phenolic hydroxyl groups of the phenols.

  The raw material phenols used in the method of the present invention may be either solid or liquid, and there is no particular limitation on the form (packaging) and purity.

  The phenols mean aromatic compounds containing one or more phenolic hydroxyl groups in the molecule. An aromatic compound is a compound having an aromatic ring, and the aromatic ring includes a non-benzene aromatic ring such as a cyclopentadiene ring; a benzene ring; a condensed aromatic ring such as a naphthalene ring, an anthracene ring, and a pyrene ring; Heteroaromatic rings (pyrrole ring, pyridine ring, thiophene ring, furan ring) in which one or more carbon atoms of the aromatic ring, aromatic ring or condensed aromatic ring are replaced by hetero atoms such as oxygen atom, nitrogen atom, sulfur atom Etc.);

  Unitary phenols include: phenol; o, m or p-cresol, o, m or p-ethylphenol, o, m or p-butylphenol, o, m or p-octylphenol, 2,3-xylenol, Phenols with hydrocarbon substituents such as 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,4-di-tert-butylphenol; o, m or p-phenylphenol, p- (α -Cumyl) phenol having an aromatic substituent such as phenol and 4-phenoxyphenol or a substituent containing an aromatic ring; phenol having an aldehyde group such as o, m or p-hydroxybenzaldehyde; ether bond such as guaiacol and guetol Phenol having a substituent containing; p-hydroxyphenethyl Phenol having a substituent containing an alcoholic hydroxyl group such as alcohol; phenol having a substituent containing an ester bond such as methyl p-hydroxybenzoate, methyl p-hydroxyphenylacetate and heptylparaben; 2,4,6-trichloro Phenol having a halogen group such as phenol and 2-amino-4-chlorophenol; phenol having a nitro group such as o or p-nitrophenol; aminophenol, 2,4,6-tris (dimethylaminophenol, p-hydroxy Examples include phenol having a substituent containing a nitrogen atom such as phenylacetamide, α-naphthol, β-naphthol, etc. Among these, phenol and cresol are preferable.

  As polyhydric phenols, catechols (catechol, protocatechuic acid, chloroacetylpyrocatechin, adrenalone, adrenaline, apomorphine, urushiol, tiron, phenylfluorone, etc.), resorcinols (resorcinol, orcin, hexyl resorcin, etc.), hydroquinone Dihydric phenols (eg, 2,3,5-trimethylhydroquinone, 2-t-butylhydroquinone, homogentisic acid ester); pyrogallols (pyrogallol, 2,3,4-trihydroxybenzophenone, lauryl gallate, gallic acid) Esters, purpurogallin, etc.), phloroglucins (eg, phloroglucin), trihydric phenols such as oxyhydroquinones (eg, oxyhydroquinone); bis (3,5-dimethyl-4 Hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfone, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (4-methyl-6-tert-butylphenol), 3,9-bis (1,1-dimethyl-2 ( β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy) ethyl-2,4,8,10-tetraoxaspiro (5,5) undecane, aluminone, atranoline, erythrin, catechin, epi Catechin, isocartamine, curcumin, coclaurine, cyanidin, syringidine, stilbestrol, tannic acid ester Bisphenols such as stealth, bisphenol A, bisphenol S, bisphenol Z, bisphenol fluorene, biscresol fluorene, phenol red, phlorizine, hexestrol, hematoxylin, pelargonidin, morin, decanolic acid; 1,4-dihydroxynaphthalene, carbonyl J acid , (R) -1,1′-bi-2-naphthol, (S) -1,1′-bi-2-naphthol, Eriochrome Black T, α-binaphthol, β-binaphthol, γ-binaphthol, etc. 1,4-dihydroxyanthraquinone, leuco-1,4-diaminoanthraquinone, leuco-1,4-dihydroxyanthraquinone, anthrahydroquinone, alizarin, alizarin S, emodin, quinizarin, kermesic acid Stealth, acidic anthraquinone dyes (alizarin safilol B and the like), hydroxyanthracenes or hydroxyanthraquinones such as purpurin and purproxanthine; citrazic acid; 1,1,3-tris (2-methyl-4-hydroxy-5-t -Butylphenyl) butane; 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-hydroxybenzyl) benzene; polyphenols, novolac resins, resole resins, atromentin, anthraquinone dyes (built) Dyed purple), usnic acid, dehydrourushiol, echinochrome, orthoserine ester, cartamine, acid mordant dye (diamond black F, chrome fast nebble B, paratin fast blue, etc.), dihydrophenylalanine ester, dilohol acid Ester, delphinidin, vitamin P, fluorescein, polymeric phenols, such as Poriporu acid; and the like.

  Among these polyhydric phenols, catechols, resorcinols, and hydroquinones are preferable as aromatic ethers having a phenolic hydroxyl group, and catechol, resorcinol, and hydroquinone are more preferable. Further, bisphenols are preferable as raw materials for aromatic ethers in which no phenolic hydroxyl group substantially remains, and bisphenol A, bisphenol S, bisphenol fluorene, and biscresol fluorene are more preferable.

  The oxirane compound as one raw material refers to a compound having one or more epoxy groups (three-membered ethers) in the molecule. For example, ethylene oxide, propylene oxide, isobutylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, aliphatic alkylene oxides such as pentylene oxide; aromatic alkylene oxides such as styrene oxide; cyclohexene oxide; It is. These oxirane compounds may be used alone or in combination of two or more. Among the above oxirane compounds, aliphatic alkylene oxides having 2 to 4 carbon atoms, that is, ethylene oxide, propylene oxide, isobutylene oxide, and 2,3-butylene oxide are preferable.

  The structure of the aromatic ether according to the present invention is represented by the following general formula (1).

In the above general formula (1), Z is a hydrocarbon residue containing an aromatic ring, and specifically, carbonization including non-benzene aromatic rings, benzene rings, condensed aromatic rings and heteroaromatic rings described above for phenols. A hydrogen residue is shown. "OH" and "O-A-OH" are groups that replace a hydrogen atom on Z, n is an integer of 1 or more and not more than the maximum number of hydrogen atoms that can be substituted on Z, and m is 1 or more and n The following integers are shown. A is represented by the following general formula (2).

In the general formula (2), R ^{1 to} R ⁴ each independently represent a hydrogen atom, an alkyl group, or an aryl group. When R ^{1 to} R ⁴ are an alkyl group and / or an aryl group, they may have various substituents. R ¹ (or R ² ) and R ³ (or R ⁴ ) may form a cyclic structure (for example, a 5-membered ring or a 6-membered ring).

  The hydroxyl group bonded to the aromatic ring of Z in the general formula (1) is a “phenolic hydroxyl group” as used herein, and the hydroxyl group bonded to A is an “alcoholic hydroxyl group” as used herein.

  Moreover, the structure of the said phenols is shown by following General formula (3).

In the general formula (3), Z and n have the same meaning as in the general formula (1). “OH” is a group that substitutes a hydrogen atom on Z.

  Among these phenols, Z is a phenyl group and n = 1 (phenol), Z is a methylphenyl group and n = 1 (cresol), Z is a phenyl group and n = 2 (catechol, resorcinol, Hydroquinone), Z is a hydrocarbon residue represented by the following general formulas (4) to (7) and n = 2 {bisphenol A [general formula (4)], bisphenol S [general formula (5)], bisphenol Fluorene [general formula (6)] and biscresol fluorene [general formula (7)]} are preferable.

  Furthermore, the structure of the oxirane compound is represented by the following general formula (8).

In the general formula (8), R ^{5 to} R ⁸ each independently represent a hydrogen atom, an alkyl group, or an aryl group. When R ^{5 to} R ⁸ are an alkyl group and / or an aryl group, they may have various substituents. R ⁵ (or R ⁶ ) and R ⁷ (or R ⁸ ) may form a cyclic structure (for example, a 5-membered ring or a 6-membered ring).

Among these oxirane compounds, R ^{5 to} R ⁸ are hydrogen atoms (ethylene oxide), any one of R ^{5 to} R ⁸ is a methyl group, and the other three are hydrogen atoms (propylene oxide), R ⁵ and R ⁶ methyl groups. R ⁷ and R ⁸ are preferably hydrogen (isobutylene oxide), R ⁵ and R ⁷ methyl groups, and R ⁶ and R ⁸ are preferably hydrogen (2,3-butylene oxide).

  The method of the present invention shows that a specific anion exchange layered compound is useful as a catalyst in producing a corresponding aromatic ether by reacting a phenol with an oxirane compound. The layered compound is also useful as a catalyst in a reaction for activating active hydrogen of various active hydrogen-containing compounds.

  The above “reaction for activating active hydrogen” means that active hydrogen is extracted from a compound having active hydrogen, or that active hydrogen of the compound is more easily dissociated. The above anion-exchange layered compound can be used for various reactions involving nucleophilic addition, that is, active hydrogen activation, by drawing active hydrogen from a compound having active hydrogen or by making active hydrogen of the compound easier to dissociate. It can use suitably for reaction of these.

  The active hydrogen means a hydrogen atom involved in a desired reaction among all hydrogen atoms of the compound. Such active hydrogen is preferably a hydrogen atom having higher reactivity than a hydrogen atom directly bonded to a carbon atom in an organic compound having no hetero atom.

Examples of the hydrogen atom include a hydrogen atom directly bonded to a heteroatom (hydrogen atom of a —NH ₂ group, —CONH group, —OH group, —SH group, etc.); a hydrogen atom bonded to carbon adjacent to an electron-withdrawing group (Α-hydrogen atom such as α-position hydrogen atom of carbonyl compound); hydrogen atom constituting substituted aromatic; hydrogen atom constituting functional group such as aldehyde group and carboxyl group;

  In addition, the compound having active hydrogen may have a plurality of active hydrogens. In this case, all of the bonding forms of these active hydrogens may be the same or different.

  The anion exchange layered compound can be suitably used as a catalyst for the reaction for activating active hydrogen described below.

Examples of the reaction involving a hydrogen atom directly bonded to a heteroatom include the following reactions (A) to (N) (reactions involving a hydrogen atom directly bonded to a heteroatom are limited to these reactions). Not.)
(A) Addition reaction of cyclic hetero compounds (ethylene oxide, ethyleneimine, ethylene sulfide, etc.) to amines (primary amines or secondary amines).
(B) Conversion reaction from amines (primary amines or secondary amines) to amides.
(C) Hydrolysis reaction of amides.
(D) Addition reaction of cyclic hetero compound to amides, for example, addition reaction of ethylene oxide to pyrrolidone or isocyanuric acid.
(E) Addition reaction of cyclic hetero compound to thioamides.
(F) Addition reaction of cyclic hetero compounds to water or alcohols (primary alcohols, secondary alcohols or tertiary alcohols), for example, ethylene oxide or propylene to water, methanol, ethanol, propanol or butanol Addition reaction of oxirane compounds such as oxide.
(G) Reaction of alcohol (primary alcohol, secondary alcohol or tertiary alcohol) with hydrogen halide, for example, reaction of synthesizing isopropyl bromide from isopropanol and concentrated hydrogen bromide.
(H) Ester synthesis reaction using alcohols (first alcohol, second alcohol or third alcohol).
(I) Oxidation reaction of alcohols (first alcohols, second alcohols or tertiary alcohols).
(J) Addition reaction of a cyclic hetero compound to phenols (phenol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, bisphenol fluorene, dihydroxydiphenylmethane, etc.).
(K) Reaction for synthesizing ethers from phenols and alkyl halides [Williamson synthesis reaction], for example, p-nitrobenzyl-p-tolyl ether from p-cresol and p-nitrobenzyl bromide Reaction to synthesize.
(L) Synthesis reaction of ester using phenols, for example, reaction of synthesizing p-nitrophenyl acetate from p-nitrophenol and acetic anhydride, or o-bromo from o-bromophenol and p-toluenesulfonyl chloride Reaction for synthesizing phenyl-p-toluenesulfonic acid.
(M) Addition reaction of a cyclic hetero compound to thiols (first thiols, second thiols or third thiols).
(N) Addition reaction of a cyclic hetero compound to thiophenols.

Examples of the reaction involving a hydrogen atom bonded to a carbon atom adjacent to the electron withdrawing group include the following reactions (O) to (V) (hydrogen bonded to a carbon atom adjacent to the electron withdrawing group). The reactions involving atoms are not limited to the following reactions).
(O) A halogenation reaction of ketones, for example, a reaction of introducing a bromine atom into cyclohexanone.
(P) Aldol condensation reaction, for example, a reaction for synthesizing 3-hydroxybutanal from acetaldehyde or a reaction for synthesizing diacetone alcohol from acetone.
(Q) Perkin condensation reaction.
(R) Knoevenagel condensation reaction.
(S) Cope reaction.
(T) Various nucleophilic addition reactions to carbonyl compounds (ketones) such as the Wittig reaction.
(U) Nucleophilic acyl substitution reaction to ketones, such as Claisen condensation reaction.
(V) Addition reaction to α, β-unsaturated carbonyl compound (ketones) [Michael addition reaction].

Examples of the reaction involving the hydrogen atom constituting the substituted aromatic include the following reactions (W) and (X) (the reaction involving the hydrogen atom constituting the substituted aromatic includes It is not limited to nuclear reactions only).
(W) Reimer-Tiemann reaction.
(X) Friedel-Crafts acylation reaction.

Examples of the reaction involving a hydrogen atom constituting a functional group such as the aldehyde group or the carboxyl group include the following reactions (Y), (Z), (a), and (b) (aldehyde and Reactions involving hydrogen atoms constituting functional groups such as carboxylic acids are not limited to the following reactions only).
(Y) Addition reaction of cyclic hetero compounds (eg, ethylene oxide, propylene oxide, etc.) to carboxylic acids (eg, acrylic acid, methacrylic acid, acetic acid, propionic acid, etc.), for example, (meth) acrylic acid and ethylene oxide Reaction to synthesize (meth) acrylic acid hydroxyethyl ester from (meth) acrylic acid hydroxypropyl ester.
(Z) Addition reaction of a cyclic hetero compound to thiocarboxylic acids.
(A) Alcohol addition reaction to aldehydes.
(B) Cannizzaro reaction, more specifically, a reaction in which trimethylolpropane is produced by subjecting n-butylformaldehyde to aldol condensation twice with n-butylformaldehyde and then carrying out the Cannizzaro reaction.

  Among the reactions involving the activation of active hydrogen in these active hydrogen-containing compounds, the anion exchange layered compound is more suitable for the reaction of adding an oxirane compound (more preferably, ethylene oxide and propylene oxide) to phenols. Preferably used.

  The anion-exchange layered compound used as a catalyst in the method of the present invention is a compound having anion-exchange ability, has a plurality of layers, and contains an anion between these layers. Refers to the resulting compound.

  For example, with regard to natural or synthesized hydrotalcite or natural or synthesized hydrotalcite-like compounds (hydrotalcite-like compounds having carbonate anions), carbonate anions are converted to other anions by a specific method. (Hereinafter, unless otherwise specified, the hydrotalcite and the hydrotalcite-like compound are collectively referred to as “hydrotalcite”).

Hydrotalcite has a plurality of brucite layers, and has anions between these layers. The brucite layer is a layer composed of double hydroxides. Specifically, as with brucite [Mg (OH) ₂ ], an octahedron centered on a divalent metal ion is two-dimensional. The divalent metal ions are partly replaced by trivalent metal ions, and the anions between the plurality of brucite layers are present for charge protection. ing. Such hydrotalcite is represented by the following general formula (9).

[M ^II _1-a M ^III _a (OH) ₂ ] [X ^m- _{a / m} · nH ₂ O] (9)
(Here, M ^II is a divalent metal, M ^III is a trivalent metal, X is an anion other than hydroxide ion, 0 <a <1, and m is an integer of 1 to 4 in terms of the valence of X. And n represents an integer of 0 to 30).

In the general formula (1), [M ^II _1-a M ^III _a (OH) ₂ ] constitutes the brucite layer, and anions (and water molecules) [X ^m- _{a / m} · nH ₂ O] exists. These anions are exchangeable.

Of the compounds represented by the general formula (9), hydrotalcite (excluding hydrotalcite-like compounds) is M ^II : Mg, M ^III : Al, X: CO ₃ , and a = 1 / 4, m = 2, n = 1/2, and other than this compound is the hydrotalcite-like compound. The natural products, addition to the hydrotalcite, Pairooro stone ^{(pyroaurite, M II: Mg,} M III: Fe, X: at _{CO 3, a = 1/4} , m = 2, n = 1/2) , etc. It has been known.

  Table 1 shows combinations of divalent metals and trivalent metals that such hydrotalcite may have. Each cell in Table 1 means a combination of a divalent metal and a trivalent metal that can be used for hydrotalcite. Among these combinations, particularly preferable ones are indicated by “◯” in the table cell. However, the hydrotalcite that can be used in the method of the present invention is not limited to those marked with ○ in Table 1, but is composed of all combinations of divalent metals and trivalent metals shown in Table 1. Is applicable. That is, the hydrotalcite composed of the combination of divalent metal and trivalent metal described in Table 1 can be synthesized even if it does not exist as a natural product. Note that Li in Table 1 is a monovalent metal, but can be used instead of a divalent metal. Further, Ti in Table 1 is a tetravalent metal, but can be used instead of a trivalent metal.

  Note that the combination of a metal such as divalent and a metal such as trivalent is not limited to those shown in Table 1 below. Further, as described above, monovalent metals and tetravalent metals can also be used as long as the hydrotalcite structure can be maintained.

  Details of such hydrotalcites are disclosed in "Anionic Clays: Trends in Pillaring Chemistry" ("Expanded Clays and Other Microporous Solids", Vol. 2, New York, 1992, p. 108-169). .

  The hydrotalcite-like compound used as a catalyst in the method of the present invention is obtained by decarboxylating a hydrotalcite-like compound having hydrotalcite or carbonate ion as an interlayer anion (hereinafter referred to as “carbonate anion-type hydrotalcite”) It is obtained by introducing an anion other than.

  The carbonate ion-type hydrotalcite becomes an oxide by dehydration and decarboxylation at 400 to 500 ° C. When the oxide is immersed in an aqueous solution containing an anion, the anion and water are obtained and hydrolyzed. It has the property of regenerating to talcite. The intercalation method in which various anions are inserted between layers using this property is a very simple method that does not need to consider the order of ion selectivity, and can be applied to many anions. The carbonate anion of type hydrotalcite can be replaced with other anions with high conversion. Here, the intercalation means a reaction in which various atoms, molecules or ions break into the weak bond between the layers of the layered crystal and are inserted between the layers in the layered compound.

  Examples of the “anions other than carbonate ions” include various inorganic anions and organic anions. As inorganic anions, halogen anions such as fluorine ion, chlorine ion, bromine ion and iodine ion; sulfate anion, thiosulfate anion, nitrate anion, phosphate anion, chlorate anion, perchlorate anion, silicate anion, chromic acid Examples include anions of inorganic acids such as anions and tungstate anions; and complex anions such as ferricyan anions and ferrocyan anions. Organic anions include acetic acid anion, propionate anion, succinate anion, glutarate anion, adipate anion, benzoate anion, terephthalate anion, etc. unit price or polyvalent carboxylate anion; methanesulfonate anion, benzenesulfonate anion And sulfonic acid anions such as p-toluenesulfonic acid anion; phenoxy anion and the like. Among these, a chloride ion, a sulfate anion, an acetate anion, a succinate anion, a glutarate anion, an adipate anion, a terephthalate anion, and a phenoxy anion are preferable, and a phenoxy anion is particularly preferable. Most preferably, it is a phenoxy anion derived from the same type of phenol as that used in the synthesis of the aromatic ether.

  In the phenoxy anion type hydrotalcite-like compound obtained by the above method (intercalation method) from the above carbonate anion type hydrotalcite, the carbonate anion is replaced with a phenoxy anion with a very high conversion rate. And, when this phenoxy anion reacts with phenols and oxirane compounds to synthesize aromatic ethers, it is exchanged with phenoxy anions derived from the phenols, which are reaction intermediates, so the reaction activity is further enhanced. Therefore, the aromatic ethers can be produced with higher yield.

An anion-exchangeable layered compound having a botalackite structure (hereinafter referred to as “botarakite-type compound”) is a copper chloride and its ion-exchange derivative. On page 82 of “Encyclopedia of Minerals (VAN NOSTRAND REINHOLD COMPANY)”, the basic structure “Cu ₂ Cl (OH) ₃ ” is categorized as “bottallackite”, but the botarakite in the present invention is the basic structure “Cu ₂ Cl”. (OH) ₃ ”and its ion exchange derivative, which means“ A ₂ (OH) ₃ (X) · nH ₂ O ”. Here, A is a divalent metal ion such as Cu ion, and may be the same type of divalent metal ion or a different type of divalent metal ion. Examples of the divalent metal ion include each ion such as Mg, Mn, Fe, Co, Ni, Cu, Zn, and Ca, but are not limited to these divalent metal ions. In addition, monovalent and trivalent metal ions can be substituted with A as long as they can retain the botalakite structure. Botarakkaito type compounds, nH in a plurality of layers indicated by _{"A 2 (OH) 3 (X} ) ", the water between the layers (the _{"A 2 (OH) 3 (X} ) · nH 2 O " ₂ O).

X is a site that directly coordinates to the metal and corresponds to Cl in the basic structure. This X can be exchanged for various anions. There are no particular restrictions on the initial anionic species of the botalakite-type compound according to the present invention. Examples thereof include hydroxide ions, halide ions (fluorine ions, chlorine ions, bromine ions, iodine ions, etc.), organic acid anions (carboxylate anions, phenoxy anions, etc.), inorganic acid anions, and the like. Inorganic acid anions include sulfate, sulfite, bisulfite, phosphate, borate, cyanide, carbonate, thiocyanate, nitrate, phosphate, hydrogenphosphate, polyanion. Oxymetalate anions (for example, molybdate anions, tungstate anions, phosphotungstate anions, metavanadate anions, pyrovanadate anions, hydrogen pyrovanadate anions, niobate anions, tantalate anions, etc.) are included. Among the anionic species exemplified above, anions of various organic acids, hydroxide ions, and halide ions are preferable. In addition to these, oxyanions such as perchlorate ions (ClO ₄ ⁻ ) and MnO ₄ ⁻ ; isopolyions; heteropolyions (AF Wells, Structural Inorganic Chemistry, 5 ^th Ed, Clarendon Press, Oxford, 1984, pp. 510-530); SCN ⁻ ; acetic acid anion or RCOO ⁻ [R: CH ₃ (CH ₂ ) _n , n = 0 to 22], monocarboxylic acid anion; R (COO ⁻ ) ₂ [ And dicarboxylic acid anions represented by R: (CH ₂ ) _n , n = 0 to 22]; silicate anions such as Si ₈ O ₂₀ ^8- ;

  Among the anionic species possessed by the botalakite type compound, a phenoxy anion is more preferable. Particularly preferred is a phenoxy anion derived from the same type of phenol as that used in the synthesis of the aromatic ether. When the botalakite-type compound has such a phenoxy anion, when the aromatic ethers are synthesized by reacting a phenol with an oxirane compound, it is exchanged with a phenoxy anion derived from the phenol as a reaction intermediate. Since the reaction activity is further increased, the aromatic ethers can be produced with higher yield.

In addition, Cu ²⁺ shown in the basic structure can be exchanged for a divalent metal ion, and synthesis examples of Zn ²⁺ / Ni ²⁺ have been reported (Material Research Society of Symposium Processings, vol. 371, 131-142, 1994), and these are included in the botalakite type compounds according to the method of the present invention.

  The anion species in the botalakite-type compound is directly coordinated to metal ions such as copper and has exchangeability, so it can be exchanged with various anions while maintaining the structure, but it is reported to show catalytic ability Has not been reported so far (there are reports on the CO oxidation ability of pyrolysates).

  The botalakite-type compound can be a highly selective catalyst because it can exchange ions while maintaining the crystal structure (that is, maintaining the uniformity of the structure). In addition, since metal acetate (botarakite type compound whose anion is acetate ion) can be used in the synthesis, there is an advantage that the synthesis conditions are flexible. When metal acetate is used for synthesis, there is little risk of corrosion of the reaction vessel. Further, since the acetic acid anion easily forms a layered structure as an interlayer anion, a botalakite type compound can be obtained in a high yield. Furthermore, the acetate anion is also characterized in that it can be easily exchanged with other anions.

  Incidentally, in order to obtain the above-mentioned botarakite-type compound having a phenoxy ion, for example, the botalakite-type compound having an acetate ion may be anion-exchanged in a solution containing a phenoxy anion to be introduced.

  In the method of the present invention, a solvent may or may not be used when the phenol and oxirane compound are reacted. In the case of using a solvent, an aqueous solvent, an organic solvent, or a mixed solvent thereof can be used.

  Specific examples of solvents other than water that can be used in the method of the present invention include alcohols having 1 to 6 carbon atoms such as methanol, ethanol, n-propanol, 2-propanol, n-butanol, hexanol, and cyclohexanol; ethylene glycol C3-C6 glycol ethers such as monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether; C2-C6 ethers such as tetrahydrofuran and dioxane; and the like. In addition, aliphatic hydrocarbons such as pentane, hexane, and heptane; aromatic hydrocarbons such as benzene, toluene, and xylene; alicyclic hydrocarbons such as cyclohexane; acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, Ketones such as cyclohexanone; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons such as dichloromethane and 1,2-dichloroethane; glycols such as ethylene glycol; pyridine; acetonitrile; dimethyl sulfoxide; dimethylformamide; ; Can also be used.

  The form of the reaction in the method of the present invention is not particularly limited. For example, the reaction may be performed in a batch system or a continuous system. In the case of the continuous system, the catalyst can be suspended in the reaction kettle, and the reaction can be advanced by passing the reaction raw material through the catalyst as a fixed bed. In the method of the present invention, the raw materials are preferably mixed uniformly during the reaction, but may be separated into two layers as long as they can be reacted.

  In carrying out the above reaction, the amount of raw material charged, the amount of catalyst, the amount of solvent, the reaction time and the reaction temperature are not particularly limited, and these conditions may be appropriately selected according to the structure of the target aromatic ether.

  For example, when producing aromatic ethers having a phenolic hydroxyl group using polyhydric phenols as phenols, it is desirable to employ the following conditions. The raw material charge amount is 0.1 to 2.0 in terms of molar ratio of the oxirane compound to the amount of the phenolic hydroxyl group to which the oxirane compound should be added among the phenolic hydroxyl groups of the polyhydric phenols. Is preferable, and it is more preferable to set it as 0.5-1.5 from a viewpoint of economical efficiency. More preferably, it is 0.9-1.2.

  On the other hand, in order to produce aromatic ethers reacted with an oxirane compound without leaving phenolic hydroxyl groups as much as possible by using unit price or polyvalent phenols as phenols, the following conditions may be adopted. Recommended. The amount of raw material charged is preferably at least 0.9 in terms of molar ratio of the oxirane compound to the amount of phenolic hydroxyl group contained in the polyhydric phenol. More preferably, it is 0.95 or more, More preferably, it is 1.0 or more. Further, the upper limit of the molar ratio of the amount of oxirane compound to the amount of phenolic hydroxyl group possessed by polyhydric phenols is preferably 5, more preferably 2, still more preferably 1.5. 2 is particularly preferred and 1.05 is most preferred.

  It is recommended that the catalyst amount, the solvent amount, the reaction time, and the reaction temperature be selected from the following ranges regardless of the structure of the target aromatic ether.

  The amount of the catalyst is preferably 1 to 70% by volume, more preferably 5 to 30% by volume with respect to the total volume of the reaction solution containing the catalyst.

  The amount of the solvent is preferably 0 to 5 and more preferably 0 to 2.5 by mass ratio with respect to the polyhydric phenols which are raw materials.

  The reaction temperature is preferably 50 to 150 ° C, more preferably 80 to 120 ° C. In consideration of productivity, the reaction time is preferably 1 to 24 hours, and more preferably 1 to 12 hours.

  Since the aromatic ethers produced by the method of the present invention have high purity, they can be used as products directly after the reaction, but if necessary, only the aromatic ethers are distilled, extracted, and crystallized after the reaction. It is also preferable to separate the product by a general method such as Moreover, you may isolate | separate only the phenols which are raw materials by methods, such as distillation, extraction, and crystallization. In addition, the phenols that are raw materials are converted using a catalyst so that the phenols are substantially absent in the system, and the products after the conversion of the phenols are separated by a general method as described above. It doesn't matter.

  Examples of the distillation method include, but are not limited to, vacuum distillation, steam distillation, molecular distillation, and extractive distillation. The crystallization method includes (1) cooling the reaction solution after completion of the reaction, (2) adding a poor solvent for the target product to the reaction solution, (3) distilling off the solvent in the reaction solution, 4) There is a method of gradually pressurizing the reaction solution, and these can be carried out alone or in combination.

  Among these, it is preferable that a solvent is used in the reaction step of the phenols and the oxirane compound, and the solvent used in the crystallization step after the reaction step is the same as the solvent used in the reaction step. In this case, the cost for solvent loss and solvent recovery is low, and the target compound can be obtained economically advantageously. Here, “common” means that different types of solvents are not added to the reaction solution obtained in the reaction step. For example, the reaction solution obtained in the reaction step is substantially subjected to the crystallization step as it is, or the same kind of solvent as that used in the reaction step is added to the reaction solution, and this is subjected to the crystallization step. This is true. In this case, all or part of the solvent used in the reaction step may be contained in the crystallization solution in the crystallization step.

  Furthermore, the crystallization process can consist of one or more crystallization stages. During the crystallization process, it is preferable not to be in an open atmosphere but to be sealed with an inert gas. In the open state, oxygen is absorbed in the crystallization mother liquor, the hue is deteriorated, and it is difficult to obtain a high-quality product. The crystallization mother liquor from which the crystallization product has been separated is circulated to the reaction step as necessary from the viewpoint of efficient use of the raw material phenols. In this case, at least a part of the crystallization mother liquor obtained in the crystallization step can be used as the raw material mother liquor. Usually, a multi-stage crystallization step and a solid-liquid separation / separation step of the crystallization product are adopted, and according to this, a plurality of types of mother liquors (phenols solutions) are obtained. The mother liquor at this stage can be used as a raw material mother liquor in the reaction process or crystallization process. In these steps, as described above, it is more efficient to use a common solvent for the reaction step and the crystallization step.

  As described above, the produced aromatic ethers can be used as long as there is no problem in use depending on the application, and in that range, after the completion of the reaction, the product remains containing unreacted raw materials and other impurities. Can be used as

  In the method of the present invention, since an anion-exchange layered compound is used as the catalyst, the crude product and the purified product after the completion of the reaction have a low content of impurities such as metals and halogens and are substantially free of metals and halogens. Products that do not contain can also be manufactured. Specifically, a metal and / or halogen content of 50 ppm or less (mass basis, the same shall apply hereinafter), more preferably 10 ppm or less is obtained.

  In the method of the present invention, since an anion-exchange layered compound is used as a catalyst, the content of impurities is small and the target compound can be produced efficiently. Furthermore, since the catalyst can be easily separated, the product can be purified efficiently. The amount of unreacted phenols can be 500 ppm or less (mass basis, the same shall apply hereinafter), preferably 100 ppm or less, more preferably 30 ppm or less with respect to the aromatic ethers. In the aromatic ethers, the proportion of impurities added excessively by the oxirane compound can be 10% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less.

  In addition, according to the method of the present invention, even when the target compound is an aromatic ether having a phenolic hydroxyl group, it can be produced with high selectivity. For example, when ethylene oxide, an oxirane compound, is reacted with catechol, which is a divalent phenol, 2- (2-hydroxyphenoxy) ethanol with one phenolic hydroxyl group remaining can be obtained with high selectivity. It is. This compound preferably has 6 mmol or more of phenolic hydroxyl group per gram. In addition, the suitable amount of this phenol hydroxyl group changes with raw material phenols and target aromatic ethers.

  Moreover, it is also preferable to make the crude product taken out from the reaction solution into a purified product with higher purity by a known purification method (crystallization, distillation, etc.). The unreacted polyhydric phenols in the aromatic ethers are easily oxidized at high temperatures, and easily change to quinones (benzoquinones, etc.) to produce the quinhydrones that cause the coloring of purified products. Quinones have sublimability and are relatively difficult to remove by distillation purification. Therefore, a crystallization method is more preferable as a method for purifying the aromatic ethers. Further, as a crystallization method in the purification step or the crystallization step of extracting the aromatic ether from the reaction solution, it is preferable to adopt the method disclosed in Japanese Patent Application No. 2003-159516, and purification is achieved by adopting this method. Crystallization can proceed stably while suppressing coloring of the product (recovered product).

  The aromatic ethers thus obtained can be used alone or mixed with other components depending on the application. There is no particular limitation on the shape and state, and it can be handled in the form of a solid (eg, powder, flakes, granules, etc.), slurry, solution (eg, organic solvent solution), etc.

  Moreover, as a form of transport and storage of the aromatic ether, there may be mentioned a crude product after completion of the reaction, a purified product, and a diluent or stabilizer added thereto. For example, from the viewpoint of preventing the oxidation of phenolic hydroxyl groups, the gas phase is replaced with an inert gas (usually oxygen concentration: 0.01 vol% or less, preferably 0.001 vol% or less), and the light is shielded from light. Is preferred. Furthermore, it is more preferable that a radical scavenger (for example, about 10 to 100 ppm by mass of phosphorous acid or phosphorous acid diester) coexists. From the viewpoint of preventing hue deterioration, it is also recommended to use slightly acidic conditions (for example, pH = about 6 to 7). In this case, for example, an aliphatic carboxylic acid (formic acid, oxalic acid, citric acid, tartaric acid, glycolic acid, lactic acid, succinic acid, malic acid, glyceric acid, etc., more preferably low-volatile lactic acid, succinic acid, etc.) Organic acids can be added. The addition amount is preferably about 1 to 1000 ppm by mass, more preferably about 5 to 100 ppm by mass. The addition time of these additives (diluent, stabilizer) is not particularly limited. In other words, any time of the reaction process, the crystallization process, the production process, and the like may be used.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.

Experiment 1
Example 1
Addition reaction of propylene oxide (PO) to phenol, which is a unit price phenol, was performed. Phenol: 10.0 g, PO: 6.47 g, and hydrotalcite-like compound: 0.5 g as a catalyst were put into a 50 ml glass pressure vessel. Subsequently, the gas phase was purged with nitrogen, sealed, and heated in an oil bath at 90 ° C. while shaking. After reacting for 14 hours, the reaction solution and the catalyst were separated by filtration.

In addition, the above-mentioned catalyst was obtained by subjecting commercially available hydrotalcite [Mg ₆ Al ₂ (OH) ₁₆ ] [CO ₃ .4H ₂ O] to a baking treatment (at atmospheric pressure) at 450 ° C. for 18 hours, It is a hydrotalcite-like compound obtained by mixing 2 g of phenol and 18 g of water with respect to 0.5 g and subjecting to activation treatment (in a nitrogen atmosphere) at 90 ° C. for 5 hours.

The reaction solution was analyzed by gas chromatography (GC). The analysis conditions are described below. All GC analyzes in this example were performed according to the following conditions. “GC-15A” manufactured by Shimadzu Corporation was used for the GC device, “DB-1 (φ32 mm × 30 m)” manufactured by J & W was used for the column, and helium was used for the carrier. The temperature condition was such that the sample was held at 70 ° C. for 5 minutes after the sample injection, then heated to 300 ° C. at a rate of 15 ° C. per minute, and then held at 300 ° C. The conversion rate and reaction selectivity of the measurement sample were calculated according to the following formula from the area ratio of the corresponding peak shown in the obtained GC chart.
Conversion rate of raw material phenol (%) = 100 × [1- {a / (a + b + c +...)}]
Reaction selectivity of product b (%) = 100 × {b / (b + c +...)}
Here, a: GC area of unreacted phenol, b, c...: GC area of each product.

  As a result of GC analysis, the raw material phenol was converted to 72.3%, and the reaction selectivity was 95.3% for the phenol PO1 adduct and 4.7% for the phenol PO2 adduct. The phenol PO1 adduct means an ether formed by reaction of one molecule of PO with one phenolic hydroxyl group, and the phenol PO2 adduct means that two molecules of PO react with one phenolic hydroxyl group. Means an ether.

Example 2
Furthermore, PO was added to phenol in the same manner as in Example 1 except that 1.35 g of water was added to the glass pressure vessel to obtain a reaction solution. As a result of GC analysis of the obtained reaction liquid, the raw material phenol was converted to 84.5%, and the reaction selectivity was 96.9% for the phenol PO1 adduct and 3.1% for the phenol PO2 adduct. It was.

Comparative Example 1
Except not using a catalyst, PO was added to phenol in the same manner as in Example 1 to obtain a reaction solution. As a result of GC analysis of the resulting reaction solution, the raw material phenol was converted to 13.3%, and the reaction selectivity was less than 1% of the phenol PO1 adduct.

Experiment 2
<Synthesis Example of Catalysts A and B>
Nickel acetate tetrahydrate: 32.8 g and zinc acetate dihydrate: 14.5 g were placed in a 200 ml volumetric flask, and deionized water was added up to the marked line. This solution was hydrothermally synthesized at 180 ° C. for 24 hours in an autoclave. Thereafter, the solution was filtered, washed with deionized water, and then vacuum dried to obtain Catalyst A. The catalyst A is represented by [Ni _4/3 Zn _2/3 (OH) ₃ (CH ₃ COO) · nH ₂ O], and is an anion in which acetate ion (CH ₃ COO) ⁻ in the formula can be exchanged. .

  NaOH and phenol were added to a 30 ml two-necked flask, deaerated water: 10 ml was added, and the mixture was stirred at 50 ° C. for 2 hours in a nitrogen stream. Thereafter, this solution (sodium phenolate solution) was added to a three-necked flask (200 ml) containing catalyst A under a nitrogen atmosphere, and stirred at 50 ° C. for 24 hours in a nitrogen stream. Thereafter, it was washed and filtered using degassed water, and vacuum dried to obtain catalyst B. The amount of sodium phenolate solution charged was twice the equivalent of the anion exchange capacity of catalyst A.

Example 3
Addition reaction of propylene oxide (PO) to phenol, which is a unit price phenol, was performed. Phenol: 5.0 g, PO: 3.1 g, and catalyst B: 0.25 g as a catalyst were put into a 50 ml glass pressure vessel. Subsequently, the gas phase was purged with nitrogen, sealed, and heated in an oil bath at 90 ° C. while shaking. After reacting for 20 hours, the reaction solution and the catalyst were separated by filtration. As a result of GC analysis of the obtained reaction liquid, the raw material phenol was converted to 85%, and the reaction selectivity was 97% for phenol PO1 adduct and 3% for phenol PO2 adduct.

Comparative Example 2
Except that no catalyst was used and the reaction time was 66 hours, PO was added to phenol in the same manner as in Example 3 to obtain a reaction solution. As a result of GC analysis of the obtained reaction liquid, the raw material phenol was converted to 26%, and the reaction selectivity was 10% for the PO1 adduct of phenol.

Claims (2)

In synthesizing aromatic ethers by reacting phenols and oxirane compounds using anion exchange layered compounds as catalysts,
A method for producing an aromatic ether, wherein a compound having a botalakite structure is used as the anion exchange layered compound. In synthesizing aromatic ethers by reacting phenols and oxirane compounds using anion exchange layered compounds as catalysts,
As the anion exchange layered compound, a hydrotalcite-like compound obtained by decarboxylating a compound having a hydrotalcite structure and having a carbonate anion between layers and introducing an anion other than the carbonate anion is used. A method for producing aromatic ethers.