JP2002249457A - Method for producing aldehyde - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing an aldehyde, especially high purity aldehyde from corresponding alcohol and/or ether. SOLUTION: The method for producing an aldehyde by oxidizing corresponding alcohol and/or ether comprises (1) an oxidation step to oxidize an alcohol and/or ether, (2) a step to form a bisulfite adduct or an oxime compound or its salt from the aldehyde obtained in the oxidation step and to separate and purify the above derivative, and (3) a step to convert the above derivative to the aldehyde. In addition, the method may comprise a catalyst recovering step to recover a catalyst from reaction mixture. Herein, an ether that has methylene groups at both sites adjacent to an oxygen atom constituting an ether linkage can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an alcohol and / or
Also, the present invention relates to a method for producing an aldehyde from ether, and particularly to a method for efficiently obtaining a highly pure aldehyde.

[0002]

2. Description of the Related Art As a method for producing a corresponding aldehyde from an alcohol, pyridium chlorochromate (PC
A chromic acid oxidation method using C) as an oxidizing agent and a method using active manganese dioxide as an oxidizing agent are known. It is also known to oxidize a primary alcohol with dimethyl sulfoxide to obtain the corresponding aldehyde.

[0003] In addition, a method of obtaining an aldehyde compound by oxidizing an alcohol using a ruthenium compound as a catalyst is also known, and various studies have been made as follows.
For example, Chem. Soc. Chem. Commu
n. , 1987, 1625, discloses the use of a catalytic amount of tetrapropylammonium perruthenate and 1.5 equivalents of 4-methylmorpholine-N-oxide to an alcohol to oxidize the alcohol to give the corresponding carbonyl. Methods for obtaining the compounds have been proposed. Also, B
ull. Chem. Soc. Jpn. , 61,3607
(1988) include dichlorotris (triphenylphosphine) ruthenium (II) and 2
A method of oxidizing allyl alcohol and benzyl alcohol using an equivalent amount of bis (trimethylsilyl) peroxide has been proposed. J. Am. Chem. So
c. , 1997, 12661 discloses a method for obtaining a carbonyl compound by oxidizing an alcohol with molecular oxygen in the presence of a catalytic amount of tetrapropylammonium perruthenate and a molecular sieve. But,
These documents do not disclose a method capable of efficiently separating the produced aldehyde from the reaction mixture.

On the other hand, as a method for producing a corresponding aldehyde from ether, a method using a peroxide, lead tetraacetate, copper nitrate or the like as an oxidizing agent is known.

In addition, a method of obtaining an aldehyde compound by oxidizing an ether using nitric acid as an oxidizing agent, and a method of converting an ether into an aldehyde using nitric oxide as an oxidizing agent in the presence of an imide compound catalyst such as N-hydroxyphthalimide. (See Japanese Patent Application Laid-Open No. 11-315036) is also known. However, no method has been proposed for efficiently separating the produced aldehyde from the reaction mixture.

Generally, when producing aldehyde, the reaction mixture often contains alcohol, ester, acetal, etc. as unreacted raw materials or by-products together with the aldehyde, and these must be separated. .
Japanese Patent Publication No. 1-30811 proposes a method using a simulated moving bed system using an X-type zeolite adsorbent as a method for decomposing a monoterpene aldehyde and a monoterpene alcohol from a mixture thereof. . However, the separation efficiency is not always satisfactory.

[0007] Although several methods have been proposed for purifying the produced aldehyde, unreacted alcohol and / or ether in the reaction mixture or ester as a by-product must be sufficiently removed from the aldehyde. Is generally difficult. For example, in purification by crystallization, separation is difficult because the physical properties of aldehydes and by-products or unreacted alcohols and / or ethers are similar. In addition, in the purification by distillation, aldehyde is a reactive compound unstable to heat and oxidative action, so that by-products are generated and the yield is reduced.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for efficiently producing a corresponding aldehyde from an alcohol and / or an ether, particularly an aldehyde having a high purity. Another object of the present invention is to provide a method for producing an aldehyde that can be industrially mass-produced.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, when the step of oxidizing alcohol and / or ether is combined with a specific separation step, the corresponding aldehyde is efficiently converted. They have found that they can be manufactured well, and have completed the present invention.

That is, the present invention relates to a method for producing a corresponding aldehyde by oxidizing an alcohol and / or an ether, wherein (1) an oxidizing step of oxidizing the alcohol and / or an ether, and (2) a step of oxidizing the alcohol and / or the ether. The present invention provides a method for producing an aldehyde, which comprises a step of deriving the obtained aldehyde into a bisulfite adduct or an oxime or a salt thereof and separating the derivative, and (3) a step of converting the derivative into an aldehyde. This production method may further include (4) a catalyst recovery step of recovering the catalyst from the reaction mixture.

The ether used in the above production method is
An ether having a methylene group at both positions adjacent to an oxygen atom constituting an ether bond is preferable.

In the oxidation step (1), the reaction may be carried out by bringing alcohol into contact with molecular oxygen, and at this time, the alcohol may be oxidized using a ruthenium catalyst. The ether may be oxidized using nitric acid.

In the step (2), for example, after the produced aldehyde is converted into a bisulfite adduct, the bisulfite is subjected to an extraction operation using water and an organic solvent to recover the bisulfite adduct from the aqueous layer. At the same time, in step (3), the bisulfite adduct may be converted to an aldehyde by hydrolysis with an acid or a base, and then subjected to an extraction operation using water and an organic solvent. Alternatively, in step (2), after the generated aldehyde is induced into an oxime salt, the aldehyde is subjected to an extraction operation using water and an organic solvent to recover the oxime salt from the aqueous layer, and in step (3), The oxime salt may be converted to an aldehyde by hydrolysis with an acid.

The alcohol used in the above production method is, for example, 1,4-diol, 1,5-diol,
1,6-diol is preferred, and o-benzenedimethanol is particularly preferred. Other preferable alcohols include, for example, aliphatic primary alcohols having about 12 to 20 carbon atoms, such as stearyl alcohol and palmitic alcohol.

The ether used in the above production method is
For example, benzyl ether is preferred, and phthalane is particularly preferred.

In the present specification, "alcohol and / or
Or "ether" may be referred to as "substrate."

[0017]

DETAILED DESCRIPTION OF THE INVENTION [Oxidation Method] In the present invention, a substrate is oxidized to produce a corresponding aldehyde. As a method of oxidizing the substrate to generate an aldehyde, a known method can be used. For example, pyridium chlorochromate (P
CC) or the like as an oxidizing agent, a method using activated manganese dioxide as an oxidizing agent, or a method of oxidizing a primary alcohol with dimethyl sulfoxide to obtain a corresponding aldehyde. Particularly preferred methods for oxidizing alcohol include a method of oxidizing alcohol with molecular oxygen and a method of using nitric acid as an oxidizing agent. A particularly preferred method of oxidizing ether is a method of oxidizing ether with nitric acid or nitric oxide.

When oxidizing a substrate with molecular oxygen,
Usually, a metal catalyst is used. The metal catalyst may be any metal or metal compound that exhibits a catalytic action when oxidizing a substrate to an aldehyde with oxygen, for example, a ruthenium catalyst, a palladium catalyst, a noble metal catalyst such as a platinum catalyst, a chromium catalyst, an iron catalyst, and manganese. Periodic table 5 for catalysts, copper catalysts, etc.
Catalysts containing elements of Groups 11 to 11; catalysts comprising heteropoly acids or salts thereof; Among these, a ruthenium catalyst, a catalyst comprising a heteropolyacid or a salt thereof, and the like are preferable.

The ruthenium catalyst includes ruthenium alone and a compound containing a ruthenium element. Specific examples of the ruthenium catalyst include, for example, metal ruthenium, ruthenium oxide, ruthenium sulfide, ruthenium hydroxide, ruthenium fluoride, ruthenium chloride, ruthenium bromide, ruthenium iodide, ruthenium sulfate, ruthenic acid or a salt thereof (for example, Ammonium ruthenate), perruthenic acid or a salt thereof (eg, tetrapropylammonium perruthenate), an inorganic ruthenium complex [eg, ruthenium hydroxyhalide (ruthenium hydroxychloride), hexaammineruthenium halide (hexaammineruthenium) Inorganic compounds such as ruthenium nitrosyl, hexahaloruthenic acid or its salts (such as sodium hexachlororuthenate)], ruthenium cyanide, organic ruthenium complexes [eg , Dodecacarbonyl triruthenium (0), dicarbonyltris (triphenylphosphine) ruthenium (II), diacetatodicarbonylbis (triphenylphosphine) ruthenium (II), dichlorotris (triphenylphosphine) ruthenium (II), Hydridotetrakis (triphenylphosphine) ruthenium (II),
Organic compounds such as dichlorobis (acetonitrile) bis (triphenylphosphine) ruthenium (II) and ruthenocene.

The valence of ruthenium may be any of 0-8. The preferred valence of ruthenium is 0 to 4.
Preferred ruthenium catalysts include metal ruthenium, ruthenium oxide, perruthenic acid or salts thereof and ruthenium complexes. Among them, metal ruthenium, ruthenium oxide and ruthenium complex are preferable. The ruthenium catalysts can be used alone or in combination of two or more.

As the heteropoly acid, condensates of various oxygen acids containing two or more different central ions can be used. Representative heteropolyacids include, for example, P, As, S
oxyacid ions of elements such as n, Si, Ti, and Zr;
It is composed of oxygen acids of elements such as V, Mo and W.
Among these, heteropolyacids containing at least one element of P, Si, V, Mo and W, especially P and V
And a heteropolyacid containing at least one element of Mo and Mo.

As the heteropolyacid anion constituting the heteropolyacid or its salt, various compositions can be mentioned, and a composition represented by “XM ₁₂ O ₄₀ ” is preferable. Note that X represents an element such as Si or P, for example.
M represents an element such as Mo, W, and V. M may be a single element or a combination of two or more elements. Examples of heteropolyacid anions having such a composition include anions of phosphomolybdic acid, phosphotungstic acid, silicomolybdic acid, silicotungstic acid, and phosphovanadomolybdic acid.

Examples of the salt of the heteropolyacid include various compounds in which at least a part of the hydrogen atom corresponding to the cation of the heteropolyacid is replaced with another cation. Examples of the replaceable cation include ammonium (N
Etc. H _4), alkali metal (Cs, Rb, K, Na , L
i), alkaline earth metals (Ba, Sr, Ca, Mg)
Etc.) can be exemplified. In particular, by replacing part of hydrogen atoms of the heteropoly acid in NH _4, heteropolyacid salt which constitutes the cation between H and NH ₄ is also excellent stability as well as catalytic activity. In this case, the proportion of NH ₄ with respect to H, for example NH ₄ / H (molar ratio) = 0.1 to 10, preferably from 0.2 to 8, more preferably about 0.3 to 5.

Among the above-mentioned heteropoly acids or salts thereof, phosphorus vanadomolybdic acid or a salt thereof represented by the following formula is preferably used. A _{3 + n} [PV _n Mo _12-n O ₄₀ ] (wherein A represents a heteropolyacid cation, and n represents 1 to 1)
Examples of the cation represented by A include a hydrogen atom and the above-mentioned cation. The value of n can be appropriately selected in consideration of oxidizing power and stability, and is preferably 4 to 10
(For example, 4 to 8), and more preferably about 5 to 8. When the heteropolyacid cation is composed of H and another cation (such as NH ₄ ), the value of n is often 4 to 10. The heteropolyacid or a salt thereof may be used alone or
More than one species can be used in combination.

The metal catalyst may be a carrier-supported metal catalyst in which a catalyst component is supported on a carrier. Supporting the catalyst component on a carrier often increases the catalytic activity. As the carrier, a conventional carrier for supporting a catalyst, for example, an inorganic carrier such as activated carbon, silica, alumina, silica-alumina, zeolite, titania, magnesia, diatomaceous earth, kaolin, and an organic carrier such as a styrene-divinylbenzene copolymer Is mentioned. Among them, activated carbon and alumina are preferred in terms of catalytic activity. As the activated carbon, activated carbon obtained from various raw materials (for example, plant-based, mineral-based, resin-based, etc.) can be used. The activated carbon may be either gas activated carbon or chemical activated carbon. The specific surface area of the carrier is, for example, 10
About 3000 m ² / g, preferably about 50 to 3000 m ²
/ G.

The supported amount of the catalyst component in the carrier-supported metal catalyst is, for example, about 0.1 to 50% by weight, preferably about 1 to 20% by weight, based on the carrier. The catalyst can be prepared by a conventional method, for example, an impregnation method, a precipitation method, an ion exchange method, or the like. The metal catalysts can be used alone or in combination of two or more.

When the substrate is oxidized by molecular oxygen, an acid (an acid other than a heteropoly acid) can be used together with the catalyst. By using the catalyst (for example, a heteropoly acid or a salt thereof) and an acid in combination, the catalytic activity may be increased. Inorganic acids such as, for example, sulfuric acid, nitric acid, hydrogen halides (hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide and the corresponding hydrohalic acids), phosphoric acid, boric acid; Formic acid, acetic acid,
Monochloroacetic acid, trichloroacetic acid, trifluoroacetic acid,
Organic acids such as carboxylic acids such as benzoic acid, sulfonic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid and naphthalenesulfonic acid; strongly acidic ion exchange such as sulfonic acid type ion exchange resins Resins. These acids can be used alone or in combination of two or more.

Among the above-mentioned acids, the pKa in the aqueous solution at 25 ° C. is 3 or less (for example, about −14 to 3), particularly 0.
The following (for example, -14 to 0) protonic acids are preferred.
Preferred acids include inorganic acids such as, for example, sulfuric acid, nitric acid, hydrogen halide (including hydrohalic acid), phosphoric acid;
Sulfonic acids; examples include haloalkanoic acids such as trichloroacetic acid.

The amount of the acid used is not particularly limited, but is, for example, about 0.01 to 250 mol%, preferably 0.1 to 200 mol%, and more preferably about 2 to 50 mol%, based on the substrate. is there. In addition, as described later, carboxylic acids such as acetic acid can be used as a reaction solvent.

When the substrate is oxidized by molecular oxygen, a co-catalyst such as dioxybenzenes such as hydroquinone or an oxidized form thereof may be present in the system, but is not always necessary.

[Oxidation Step (1)] The method for producing an aldehyde of the present invention includes an oxidation step (1) for oxidizing a substrate by the above-mentioned oxidation method.

The alcohol includes an aliphatic alcohol, an alicyclic alcohol, an aromatic alcohol and a heterocyclic alcohol. These alcohols may have a plurality of hydroxyl groups in the molecule.

Examples of the aliphatic alcohol include:
Methanol, ethanol, 1-propanol, 1-butanol, 2-methylpropanol, 1-pentanol,
1-hexanol, 1-heptanol, 2-ethyl-1
-Hexanol, 1-octanol, 1-decanol,
1-dodecanol, 1-tetradecanol, 1-hexadecanol (palmitin alcohol), 1-octadecanol (stearyl alcohol), icosanol, allyl alcohol, 3-methyl-2-buten-1-ol,
Monohydric alcohols such as 3,7-dimethyl-2,6-octadien-1-ol (geraniol); dihydric alcohols such as ethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol;
Examples thereof include saturated or unsaturated aliphatic primary alcohols such as polyhydric alcohols such as glycerin.

Examples of the alicyclic alcohol include monocyclic or polycyclic alicyclic primary alcohols such as cyclohexylmethyl alcohol, 2-cyclohexylethyl alcohol, and 1-hydroxymethyladamantane. As the aromatic alcohol, for example, benzyl alcohol, 2-phenylethyl alcohol, 3-phenylpropyl alcohol, 3-phenyl-2-propene-
C1-C30 such as 1-ol (preferably 7-1)
About 8) aromatic primary alcohols and the like.
Examples of the heterocyclic alcohol include furfuryl alcohol, 2-hydroxymethylthiophene, 2-hydroxymethylpyridine, 3-hydroxymethylpyridine,
At least one hetero atom selected from an oxygen atom, a sulfur atom and a nitrogen atom, such as 4-hydroxymethylpyridine, 2-hydroxymethylquinoline, 1- (3-hydroxypropyl) piperidine, and 2-hydroxymethylmorpholine; Having a heterocyclic ring containing about 3 to about 3,
Primary alcohols and the like can be exemplified.

These alcohols may have various substituents in the molecule. Examples of such a substituent include a halogen atom, a substituted oxy group (eg, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an acyloxy group, a silyloxy group, etc.), a mercapto group, a substituted thio group (eg, an alkylthio group, An alkylthio group, an arylthio group, etc.), a carboxyl group, a substituted oxycarbonyl group (eg, an alkyloxycarbonyl group, an aryloxycarbonyl group, etc.), a substituted or unsubstituted carbamoyl group, a cyano group, an acyl group, a formyl group,
Examples include a nitro group, a substituted or unsubstituted amino group, an alkyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, and a heterocyclic group.

The alcohols may be used alone or as a mixture of two or more. In the present invention, among the above alcohols, aliphatic primary alcohols, particularly those having 12 carbon atoms
Good results are obtained when the aliphatic primary alcohols of -20 to 20 are used as raw material alcohols. More preferably, at least one alcohol selected from stearyl alcohol and palmitic alcohol is used as a raw material.

The present invention also relates to alcohols such as 1,4-diol and 1,5-diol having a primary hydroxyl group (hydroxyl group constituting the primary alcohol) at both terminals.
In the case where -diol or 1,6-diol is used, the corresponding aldehyde (dialdehyde) can be obtained efficiently.

In the present specification, 1,4-diol means 4 carbon atoms (4 carbon atoms) between two hydroxyl groups.
1,5-diol refers to a diol in which five carbon atoms (carbon chain having 5 carbon atoms) are interposed between two hydroxyl groups,
1,6-diol refers to a diol in which six carbon atoms (a carbon chain having 6 carbon atoms) are interposed between two hydroxyl groups. Such diols include chain diols, cyclic compounds in which a hydroxyalkyl group (hydroxymethyl group, 2-hydroxymethyl group or 3-hydroxypropyl group) is bonded to two carbon atoms constituting a ring, and the like. It is.

As the 1,4-diol, 1,5-diol and 1,6-diol, for example, 1,4-diol represented by the following formula (1) and 1,4-diol represented by the following formula (2) 5
-Diol and 1,6-diol represented by the formula (3).

Embedded image [In the formula (1), R ^a and R ^b are the same or different and each represent a hydrogen atom, a hydroxyl group which may be protected by a protecting group, a hydrocarbon group or a heterocyclic group. R ^a and R ^b may be bonded to each other to form a ring with a double bond or two adjacent carbon atoms. In the formula (2), R ^c , R ^d , R
^e represents the same or different and represents a hydrogen atom, a hydroxyl group, a hydrocarbon group or a heterocyclic group which may be protected by a protecting group. At least two groups out of R ^c , R ^d and R ^e may be bonded to each other to form a ring with a double bond or an adjacent carbon atom. In the formula (3), R ^f , R ^g ,
R ^h and R ⁱ are the same or different and each represent a hydrogen atom, a hydroxyl group, a hydrocarbon group or a heterocyclic group which may be protected by a protecting group. At least two groups out of R ^f , R ^g , R ^h and R ⁱ may be bonded to each other to form a ring with a double bond or an adjacent carbon atom.

As the protecting group for the hydroxyl group, known or commonly used protecting groups in the field of organic synthesis can be used. In the above formula, R ^a , R ^b , R ^c , R ^d , R ^e , R ^f , R ^g ,
The hydrocarbon group for R ^h and R ⁱ includes an aliphatic hydrocarbon group,
An alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a bonded group thereof are included. Examples of the aliphatic hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl,
1-20 carbon atoms such as hexyl, decyl and dodecyl groups
(Preferably 1 to 10) alkyl groups; about 2 to 20 (preferably 2 to 10) alkenyl groups such as vinyl, allyl and 1-butenyl groups; and 2 to 20 carbon atoms such as ethynyl and propynyl groups. About 2 to 10 alkynyl groups are preferable.

Examples of the alicyclic hydrocarbon group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
3 to 20 members (preferably 3 to 1) such as a cyclooctyl group
A 5-membered, more preferably 5-8 membered) cycloalkyl group; a cycloalkyl group such as a cyclopentenyl or cyclohexenyl group;
~ 20 members (preferably 3-15 members, more preferably 5 members
To 8 membered) cycloalkenyl groups.
Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having about 6 to 14 (preferably 6 to 10) carbon atoms, such as phenyl and naphthyl groups.

Examples of the hydrocarbon group in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are bonded include cycloalkyl-alkyl groups such as cyclopentylmethyl, cyclohexylmethyl and 2-cyclohexylethyl (for example, C _3-20 Cycloalkyl-C _1-4 alkyl group). Further, the hydrocarbon group in which the aliphatic hydrocarbon group and the aromatic hydrocarbon group are bonded includes an aralkyl group (for example, a C _7-18 aralkyl group), an alkyl-substituted aryl group (for example,
A phenyl group or a naphthyl group substituted with about four C _1-4 alkyl groups) and the like.

Preferred hydrocarbon groups include C _1-10 alkyl, C _2-10 alkenyl, C _2-10 alkynyl, C _3-15
Examples include a cycloalkyl group, a C _6-10 aromatic hydrocarbon group, a C _3-15 cycloalkyl-C _1-4 alkyl group, a C _7-14 aralkyl group and the like. The hydrocarbon group includes various substituents, for example, a halogen atom, an oxo group, a hydroxyl group, a substituted oxy group (for example, an alkoxy group, an aryloxy group, an aralkyloxy group, an acyloxy group, etc.), a carboxyl group, a substituted oxycarbonyl It may have a group, a substituted or unsubstituted carbamoyl group, a cyano group, a nitro group, a substituted or unsubstituted amino group, a heterocyclic group, and the like.

R ^a , R ^b , R ^c , R ^d , R ^e , R ^f , R ^g ,
The heterocyclic ring constituting the heterocyclic group for R ^h and R ⁱ includes an aromatic hetero ring and a non-aromatic hetero ring. As such a heterocyclic ring, for example, a heterocyclic ring containing an oxygen atom as a hetero atom (for example, a 5-membered ring such as furan, tetrahydrofuran, oxazole, isoxazole, etc.)
-Oxo-4H-pyran, tetrahydropyran, 6-membered ring such as morpholine, benzofuran, isobenzofuran,
4-oxo-4H-condensed ring such as chromene, chroman, isochroman, etc., heterocyclic ring containing sulfur atom as a hetero atom (for example, 5-membered ring such as thiophene, thiazole, isothiazole, thiadiazole, etc., 4-oxo-4H
A 6-membered ring such as thiopyran, a condensed ring such as benzothiophene), a heterocyclic ring containing a nitrogen atom as a hetero atom (for example, a 5-membered ring such as pyrrole, pyrrolidine, pyrazole, imidazole, triazole, pyridine, pyridazine, pyrimidine, 6-membered rings such as pyrazine, piperidine and piperazine, condensed rings such as indole, indoline, quinoline, acridine, naphthyridine, quinazoline and purine). The heterocyclic group includes, in addition to the substituents that the hydrocarbon group may have, an alkyl group (for example, a C _1-4 alkyl group such as a methyl or ethyl group), a cycloalkyl group, and an aryl group. (E.g., a phenyl or naphthyl group).

[0045] R ^a and R ^b; R ^c, at least two groups of R ^d and R ^e; or R ^f, R ^g, carbon least two groups of R ^h and R ⁱ are adjacent bonded to each other The ring which may be formed together with the atom includes, for example, an aromatic carbon ring such as a benzene, naphthalene and anthracene ring; and a 3 to 2 ring such as a cyclobutane, cyclopentane, cyclohexane, cyclohexene, cyclooctane and cyclododecane ring.
0 members (preferably 3 to 15 members, more preferably 5 to 1
About 2 members) non-aromatic carbocycle (cycloalkane ring, cycloalkene ring or bridged carbocycle); aromatic heterocycle such as furan, thiophene, pyrrole, pyridine, quinoline ring; oxolane, oxane, azolidine, Non-aromatic heterocycles of about 3 to 20 members (preferably 3 to 12 members, more preferably 3 to 8 members) such as perhydroazine, thiolane, and thiane rings (particularly non-aromatic heterocycles containing an oxygen atom, a nitrogen atom, or a sulfur atom) Aromatic heterocyclic ring). These rings may have the same substituents as the substituents that the heterocyclic group may have, and other rings (non-aromatic rings or aromatic rings) may be condensed. May be.

R ^a , R ^b , R ^c , R ^d , R ^e , R ^f , R ^g ,
R ^h, in the preferred groups as R ⁱ is a hydrogen atom, protected optionally protected hydroxyl group in group, C _1-10 alkyl group, C _2-10 alkenyl group, C _2-10 alkynyl, C _{3- Fifteen}
Examples include a cycloalkyl group, a C _6-10 aromatic hydrocarbon group, a C _3-12 cycloalkyl-C _1-4 alkyl group, and a C _7-14 aralkyl group. R ^a and R ^b ; R ^c , R ^d and R ^e
Or at least two groups; or R ^f , R ^g , R ^h and R ⁱ
At least two groups are bonded to each other to form a double bond or an adjacent carbon atom and an aromatic carbocyclic ring, an aromatic heterocyclic ring, or a non-aromatic carbocyclic ring or non-aromatic having about 3 to 20 members. It is also preferable to form an aromatic heterocyclic ring (among others, an aromatic carbon ring or an aromatic heterocyclic ring).

Representative examples of 1,4-diol, 1,5-diol and 1,6-diol represented by the formulas (1) to (3) include, for example, 1,4-butanediol, 5
-Pentanediol, 1,6-hexanediol, second
Linear diols such as polyhydric alcohols having a protected secondary hydroxyl group (eg, alditol derivatives such as xylitol, sorbitol, and mannitol having a protected secondary hydroxyl group); o-benzenedimethanol (o-xylylene) Alcohol), 2,3-naphthalenedimethanol, 1,8-naphthalenedimethanol, 1-
(2-hydroxyethyl) -8-hydroxymethylnaphthalene, 2- (2-hydroxymethylphenyl) ethanol, 1,2-cyclohexanedimethanol, 3,4-
A hydroxyalkyl group (for example, an adjacent carbon atom) is formed on two carbon atoms (for example, adjacent carbon atoms) constituting a ring such as frangimethanol, 3,4-thiophenedimethanol, 2,3-pyridinedimethanol, and 2,3-quinolinedimethanol. Hydroxymethyl group, 2-hydroxyethyl group or 3
-Hydroxypropyl group) to which an aromatic or non-aromatic cyclic compound (the ring may have a substituent) is exemplified. Among them, o-benzenedimethanol (o-xylylene alcohol) is preferable.

The ether used as the substrate may be any of a chain ether such as an aliphatic ether, an alicyclic ether, an aromatic ether and a heterocyclic ether; and a cyclic ether. In the cyclic ether, an aromatic or non-aromatic ring may be condensed with a ring containing an ether bond. Further, the ether may have a plurality of ether bonds in the molecule.

Preferred ethers include the following formula (4)

Embedded image [Wherein R ¹ and R ² are the same or different and each represent a hydrogen atom, a hydrocarbon group, a heterocyclic group, a hydroxyl group or a substituted oxy group. R ¹ and R ² may be bonded to each other to form a ring together with the adjacent carbon atom and oxygen atom], and an ether having a methylene group at both positions adjacent to the oxygen atom constituting the ether bond is included. It is.

In the formula, the hydrocarbon group for R ¹ and R ² includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Examples of the aliphatic hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, hexyl,
Alkyl groups having about 1 to 15 (preferably 1 to 10) carbon atoms such as octyl and decyl groups; alkenyl groups having about 2 to 15 (preferably 2 to 10) carbon atoms such as vinyl and 2-propenyl groups; 2 carbon atoms such as propynyl group
And about 15 (preferably 2 to 10) alkynyl groups.

Examples of the alicyclic hydrocarbon group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
C3-C3 such as cyclooctyl and cyclohexenyl groups
About 15 (preferably 3 to 10) cycloalkyl groups or cycloalkenyl groups are exemplified. The non-aromatic carbon ring constituting the alicyclic hydrocarbon group may be condensed with a carbon ring such as a benzene ring and a cyclohexane ring and a heterocyclic ring such as a pyridine ring.

Examples of the aromatic hydrocarbon group include phenyl and naphthyl groups. The aromatic ring constituting the aromatic hydrocarbon group may be condensed with a carbon ring such as a cyclohexane ring or a heterocyclic ring such as a pyridine ring.

The heterocycle corresponding to the heterocyclic group represented by R ¹ and R ² includes, for example, furan, oxazole, isoxazole, thiophene, thiazole, isothiazole, thiadiazole, pyrrole, pyrazole, imidazole, triazole, pyridine, pyridazine And a 5- or 6-membered heterocyclic ring having about 1 to 3 at least one heteroatom selected from nitrogen, oxygen and sulfur atoms, such as a pyrimidine ring and a pyrazine ring. This heterocyclic ring may be condensed with a carbon ring such as a benzene ring or a cyclohexane ring, or a heterocyclic ring such as a pyridine ring.

The substituted oxy group in R ¹ and R ² is a group which can be converted into a hydroxyl group by water in the reaction system, for example, an alkoxy group such as methoxy, ethoxy, isopropoxy group (for example, C _1-4 alkoxy group). Alkenyloxy group such as allyloxy group (for example, C _2-4
Alkenyloxy group and the like); and acyloxy groups such as acetoxy and benzoyloxy groups (for example, C _2-10 acyloxy group and the like).

The ring formed by bonding R ¹ and R ² together with adjacent carbon atoms and oxygen atoms includes oxirane, oxetane, 2,5-dihydrofuran, tetrahydrofuran, 3,6-dihydropyran, tetrahydropyran , Dihydrooxepin, tetrahydrooxepin, oxepane, dihydrooxocin, tetrahydrooxocin, oxocan, 1,3,5,7-tetraoxocan,
3 to 20 members containing at least one oxygen atom (preferably 3 to 15 members, more preferably 3 to 15 members, such as dihydrooxonin, dioxane, dihydrodioxin, dihydrooxathiin, tetrahydrooxathiin, dihydrooxazine, and perhydrooxazine ring) Non-aromatic heterocycle of about 4 to 10 members). This ring includes a carbon ring such as a benzene ring and a cyclohexane ring (for example, 3 to 1).
A heterocyclic ring such as a 5-membered aromatic or non-aromatic carbon ring) or a pyridine ring (for example, a 3- to 15-membered aromatic or non-aromatic heterocyclic ring) may be condensed. As a condensed ring obtained by condensing such a carbocyclic or heterocyclic ring, for example,
Coumaran, isocoumarin (phthalane), chroman, chromene, isochroman, isochromene, xanthene, benzoxazine, 3,6,8-trioxabicyclo [3.
2.2] Nonane ring and the like. When R ¹ and R ² combine to form a ring with adjacent carbon atoms and oxygen atoms, the ether represented by the formula (4) forms a cyclic ether.

The hydrocarbon group, the heterocyclic group, and the ring formed by bonding R ¹ and R ² together with the adjacent carbon atom and oxygen atom include various substituents such as a halogen atom (iodine, bromine, Chlorine and fluorine atoms), an oxo group, a hydroxyl group, a mercapto group, a hydroxyalkyl group (eg, a hydroxy C _1-4 alkyl group such as hydroxymethyl, 2-hydroxyethyl group, etc.), a substituted oxy group [eg, an alkoxy group (eg, A C _1-4 alkoxy group such as a methoxy group), an aryloxy group, an acyloxy group (a C _2-10 acyloxy group such as acetoxy or benzoyloxy group), a substituted thio group, a carboxyl group, a substituted oxycarbonyl group (for example, Methoxycarbonyl, ethoxycarbonyl, hexyloxycarbonyl and other alkoxy moieties having 1 carbon atom About 6, in particular such as about 1 to 4 alkoxycarbonyl group), a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted amino group, a cyano group, a nitro group,
An alkyl group (eg, a C _1-4 alkyl group), an alkenyl group (eg, a C _2-4 alkenyl group), an alkynyl group (eg, a C _2-4 alkynyl group), a cycloalkyl group, a cycloalkenyl group, An aryl group (for example, a phenyl or naphthyl group), an aralkyl group, a heterocyclic group and the like may be substituted.

Among the ethers represented by the formula (4), particularly preferred compounds include (i) a compound in which R ¹ is a 1-alkenyl group (for example, 1-C ₂ such as vinyl, 1-propenyl and 1-butenyl group). _-15 alkenyl group, etc.), (i
i) R ¹ is bonded to R ² to form a non-aromatic heterocyclic ring having about 3 to 20 members (preferably 3 to 15 members, more preferably 4 to 10 members) together with adjacent carbon atoms and oxygen atoms ( Compounds forming a carbocyclic or heterocyclic ring (which may be condensed) (particularly compounds having a double bond or an aromatic ring at a position adjacent to a carbon atom bonded to an oxygen atom constituting an ether bond) ) Is included.

In the present invention, a particularly preferred compound as a substrate is “benzyl ether (including cyclic ether)” having an aromatic ring at a position adjacent to a carbon atom bonded to an oxygen atom constituting an ether bond.

Among the ethers used as substrates in the present invention, preferred compounds include, for example, dimethyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, diheptyl Ether, 1-chloro-2-ethoxyethane, bis (2-chloroethyl)
Di-C _1-15 alkyl ethers which may have a substituent, such as ether, 2-ethoxyethanol, 2,2′-oxydiethanol, and 3,3′-oxydipropionic acid (preferably di-C _{1 -10} alkyl ether); diC _2-15 which may have a substituent, such as diallyl ether;
Alkenyl ether (preferably di C _2-10 alkenyl ether); ethyl methyl ether, 2-methoxypropane, methyl butyl ether, 2-methoxybutane, 2
-Methoxypentane, 1-ethoxypropane, 2-ethoxypropane, 1-ethoxybutane, 2-ethoxybutane, 1-ethoxypentane, 2-ethoxypentane, 2
Optionally substituted asymmetric C _1-15 alkyl C _1-15 alkyl ethers (preferably asymmetric C _1-10 alkyl C _1-10 alkenyl ethers) such as methoxyethanol; vinyl allyl ethers and the like. An optionally substituted asymmetric C _2-15 alkenyl C _2-15 alkenyl ether (preferably an asymmetric C _2-10 alkenyl C _2-10 alkenyl ether); methyl vinyl ether, methyl allyl ether, ethyl allyl ether , ethoxy ethylene, 3-ethoxy propylene like, which may have a substituent C _1-15 alkyl C _2-15 alkenyl ether (preferably, C _1-10 alkyl C _2-10 alkenyl ethers); cyclopropyl Ethyl ether, cyclopropyl propyl ether, cyclopropyl butyl ether, cyclobutyl ethyl ether, cycle Butyl propyl ether, cyclobutyl ether, cyclopentyl ether, cyclopentyl propyl ether, cyclopentyl ether, cyclohexyl ethyl ether, cyclohexyl propyl ether, such as cyclohexyl ether, optionally substituted C
_1-15 alkyl C _3-15 cycloalkyl ether (preferably C _1-10 alkyl C _3-10 cycloalkyl ether);
Optionally substituted C _2-15 alkenyl C _3-15 cycloalkyl ether (preferably C _2-10 alkenyl C _3-10 cycloalkyl ether) such as allyl cyclohexyl ether; methylphenyl ether (anisole ), Ethyl phenyl ether (phenetole), propyl phenyl ether, anethole, naphthyl methyl ether, naphthyl ethyl ether, tolyl ethyl ether, 2-methoxyphenol, eugenol and the like, and optionally substituted C _1-15 alkyl. Aryl ethers (preferably C _1-10 alkyl aryl ethers);
C _1-15 alkyl aralkyl ether which may have a substituent such as benzyl methyl ether, benzyl ethyl ether, benzyl propyl ether (preferably,
C _1-10 alkyl aralkyl ether); optionally substituted C _2-15 alkenyl aryl ethers such as allyl phenyl ether (preferably C _2-10 alkenyl aryl ether); which may have a substituent C _2-15 alkenyl aralkyl ethers (preferably, C _2-10 alkenyl aralkyl ether); 1,2-dimethoxyethane, diethylene glycol dimethyl ether, 3,6-dioxy-octane, p- dimethoxy Benzene, p-diethoxybenzene, 1,1 '-(ethylenedioxy) dibenzene, 4,
A chain polyether having a plurality of ether bonds which may have a substituent, such as 4 '-(ethylenedioxy) dibenzoic acid; oxirane, oxetane, propylene oxide, 2,5-dihydrofuran, tetrahydrofuran,
2-methyltetrahydrofuran, 1,3,5,7-tetraoxocan, dioxane, coumaran, isocoumarin (phthalane), phthalide, chroman, chromene, isochroman, isochromene, xanthene, benzoxazine, 3,6,8-trioxabicyclo [3.2.2] Nonane, crown ether, 1-oxaspiro [4.5]
Examples thereof include optionally substituted cyclic ethers such as decane and tetrahydropyran-2-spirocyclohexane.

The reaction conditions can be appropriately selected according to the oxidation method.

For example, when oxidizing an alcohol by bringing it into contact with molecular oxygen (the oxidation method using the metal catalyst), the molecular oxygen is not particularly limited. Pure oxygen may be used as molecular oxygen, or oxygen or air diluted with an inert gas such as nitrogen, helium, argon, or carbon dioxide may be used. The amount of molecular oxygen used is usually 0.5 mol or more (for example, 1 mol or more), preferably 1 to 100 mol, more preferably 1 mol, per mol of alcohol.
About 50 mol. Often, an excess of molecular oxygen relative to the alcohol is used. When supplying oxygen continuously to the reaction system, the flow rate, for example, per volume one liter of reaction solution, 0.0001~10m ³ (STP) / min, preferably about 0.01~5m ³ ( (Standard state) / min.

The amount of the catalyst used can be appropriately selected depending on the type of the substrate and the catalyst used in the oxidation reaction. For example, in the oxidation method using a ruthenium catalyst, the amount of the ruthenium catalyst used (as ruthenium) is based on 1 mole of alcohol.
The amount is about 0.001 to 2 mol, preferably about 0.01 to 1.2 mol, and more preferably about 0.02 to 1 mol.

The reaction may be carried out in the presence or absence of a solvent. The solvent can be appropriately selected depending on the type of the substrate and the target product, the oxidation method, and the like. As the solvent, benzene, toluene, xylene, ethylbenzene,
Benzene rings such as trifluoromethylbenzene, chlorobenzene, anisole, benzonitrile, nitrobenzene, and ethyl benzoate are substituted with halogen atoms, alkyl groups, haloalkyl groups, alkoxy groups, cyano groups, nitro groups, substituted oxycarbonyl groups, etc. Benzene derivatives which may be used; aliphatic hydrocarbons such as hexane, heptane and octane; alicyclic hydrocarbons such as cyclohexane; haloalkanes such as carbon tetrachloride, chloroform, dichloromethane and 1,2-dichloroethane; ketones such as acetone and methyl ethyl ketone Esters such as methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; N, N-
Amides such as dimethylformamide and N, N-dimethylacetamide; nitriles such as acetonitrile and propionitrile; and linear or cyclic ethers such as diethyl ether, dibutyl ether, dimethoxyethane, dioxane and tetrahydrofuran. Preferred solvents include the above-mentioned benzene derivatives such as benzene, toluene, and trifluoromethylbenzene, haloalkanes such as 1,2-dichloroethane, and esters such as ethyl acetate. Among them, a benzene derivative in which a benzene ring such as ethylbenzene or trifluoromethylbenzene is substituted with an alkyl group, a haloalkyl group or the like is preferable.
These solvents are used alone or in combination of two or more.

The reaction temperature can be appropriately selected according to the type of the substrate and the oxidation method, and is, for example, about 0 to 200 ° C., preferably about 10 to 150 ° C., and more preferably about 50 to 120 ° C. The reaction may be performed at normal pressure or under pressure. The reaction pressure is usually 0 to 6 MPaG (gauge),
Preferably 0 to 4 MPaG, more preferably 0 to 2 M
It is about PaG. The reaction may be performed by any method such as a batch system, a semi-batch system, and a continuous system. The reactor may be a single tank, or two or more tanks may be connected continuously. The reactor may be any of a reactor with a stirrer, a fluidized bed reactor, a fixed unreacted reactor, and the like.

When the alcohol used as a raw material is 1,4-diol, 1,5-diol or 1,6-diol, the reaction is preferably performed under neutral or acidic conditions. When 1,4-diol, 1,5-diol or 1,6-diol is reacted with oxygen under basic conditions, the cyclized product lactone (γ-lactone, δ-lactone or ε-lactone) May be easily generated, and the selectivity of the target aldehyde (dialdehyde) may be significantly reduced. For example, when o-benzenedimethanol is oxidized under basic conditions, the amount of phthalide produced increases significantly and the selectivity of the desired o-phthalaldehyde decreases.

The reaction may be carried out in the form of reactive distillation in which the reaction proceeds while distilling off by-produced water. Depending on the reaction conditions and the substrate, the conversion may be improved by performing the reaction while distilling off the by-produced water, or side reactions such as polymerization of the generated aldehyde may be suppressed. Reactive distillation is
The reaction can be carried out by a reactor equipped with a reactor and a separator (decanter). It is preferable to use azeotropic distillation to remove water from the viewpoint of removal efficiency. Therefore, it is advantageous to use a solvent azeotropic with water and capable of being separated from water, such as toluene and ethylbenzene, as the reaction solvent.

When 1,4-diol, 1,5-diol or 1,6-diol is reacted with oxygen in the presence of a metal catalyst to form a corresponding dialdehyde,
When reacted in the presence of water, the formation of by-products is suppressed,
The desired dialdehyde can be obtained in a high yield. Therefore, it is preferable to react without removing water to the outside of the system or by adding water to the reaction system.

In the oxidation method using nitric acid as the oxidizing agent (oxidation of alcohol and / or ether), the nitric acid is not particularly limited, and a commercially available nitric acid can be used. Nitric acid may be diluted with water or an inert organic solvent before use. The amount of nitric acid used is, for example, 0.2 mol per mol of the substrate.
About 20 mol, preferably 1 to 10 mol.

In the oxidation method using nitric oxide as an oxidizing agent (oxidation of ether), pure nitric oxide may be used, and the nitric oxide may be diluted with an inert gas such as nitrogen, helium, argon or carbon dioxide. Nitric oxide may be used. Further, nitric oxide generated in the reaction system can also be used. The amount of nitric oxide used is, for example, 5 moles or more (for example, 5 to 30 moles) per mole of ether.
Mol), preferably 5 to 20 mol, more preferably about 6 to 20 mol (especially 8 to 20 mol).

The above reaction conditions can be appropriately selected according to each oxidation method.

As described above, an aldehyde corresponding to the substrate is formed. In particular, when alcohol reacts with molecular oxygen in the presence of a metal catalyst, the oxidation reaction proceeds smoothly under mild conditions, and by-products (eg, acetal of aldehyde and alcohol, acid, etc.) are reduced, The resulting aldehyde is obtained in good yield. Furthermore, even when oxidizing a substrate having a hydroxyl group at the so-called allyl position or benzyl position, there is no by-product of a saturated compound due to intramolecular hydrogen transfer, and the corresponding unsaturated aldehyde or aromatic aldehyde is produced in good yield.

From the diols represented by the above formulas (1), (2) and (3), the following formulas (5) and (5)
The dialdehyde represented by (6) or (7) is produced.

Embedded image [Wherein, R ^a , R ^b , R ^c , R ^d , R ^e , R ^f , R ^g , R ^h , R
ⁱ is the same as above]

When the ether is oxidized by the oxidation method of the present invention, the carbon site adjacent to the oxygen atom of the ether bond is oxidized even under mild conditions, and the corresponding aldehyde can be efficiently produced. For example, when the ether represented by the above formula (4) is oxidized, the corresponding formula (8)

Embedded image [Wherein R ¹ and R ² are the same as above], or when the compound represented by the formula (8) is a cyclic ether, a dialdehyde (R ¹ and R ² Is formed).

The reaction mixture obtained in the above oxidation step includes:
In addition to the generated aldehyde, it contains a reaction solvent and usually a reaction by-product corresponding to each oxidation reaction, so that it is necessary to separate them. The reaction by-products generally include low-boiling by-products having a lower boiling point than the target aldehyde and high-boiling by-products having a higher boiling point than the aldehyde (such as carboxylic acids, acetals, and derivatives thereof).

[Catalyst Recovery Step (4)] When a solid catalyst such as a supported catalyst having a catalyst component supported on a carrier is used as the catalyst, the reaction mixture obtained by the reaction is usually subjected to a catalyst recovery step. You. In this catalyst recovery step, the catalyst is recovered by conventional solid separation means such as filtration.

The filtration can be performed using one or more filtration devices. The temperature at which the catalyst is separated by filtration can be appropriately selected within a temperature range in which aldehyde is not precipitated without impairing workability and filtration efficiency, and varies depending on the type of aldehyde to be produced, but is usually -20 to 100 ° C, preferably It is about 5 to 90 ° C. The separated and recovered catalyst can be recycled to the reaction system.

When the catalyst is reused, it may be subjected to replacement washing with a reaction solvent and, if necessary, heating and washing, and then reused. As the solvent used for washing, the solvents listed as the solvent used for the above reaction can be used. The solvents may be used alone or as a mixture of two or more.

[Step (2)] Step (2) in the present invention
In this method, the produced aldehyde present in the reaction mixture is converted into a bisulfite adduct or an oxime or a salt thereof, and the derivative is separated.

In order to guide the aldehyde to the bisulfite adduct, specifically, the reaction mixture (the reaction solution at the end of the reaction or the reaction solution is subjected to treatment such as filtration, concentration, dilution, extraction, and liquid property adjustment) ), And a bisulfite metal salt such as sodium bisulfite and potassium bisulfite is added to the resulting mixture to form a bisulfite adduct of an aldehyde. Next, by an extraction operation using water and an organic solvent, the bisulfite adduct is extracted into the aqueous layer, and the unreacted substrate and reaction by-product that migrate to the organic layer can be separated.

In this case, water can be supplied as a solvent for the metal bisulfite. When the reaction solvent is an organic solvent that can be separated from water, the reaction solvent can be used as it is as an extraction solvent without adding a new organic solvent. Therefore, for example, when water and an organic solvent coexist in the reaction mixture in which the bisulfite adduct of the aldehyde is generated, it is possible to separate the bisulfite adduct by performing a liquid separation operation. it can. Such a separation operation is also included in the “extraction operation using water and an organic solvent”.

The amount of the metal bisulfite such as sodium bisulfite is 0.01 to 20 mol, preferably 0.5 to 5 mol, per 1 mol of the aldehyde in the reaction mixture.
More preferably, it is about 1 to 3 mol. The temperature during induction of the bisulfite adduct and the temperature during extraction (during separation) are -20.
To 50 ° C, preferably -20 to 30 ° C. According to this temperature range, dissolution of products (by-products) other than the bisulfite adduct in water can be minimized.

An extraction operation may be performed by adding an organic solvent to the reaction mixture in which the bisulfite adduct of the aldehyde has been formed. As the organic solvent used at this time, any solvent that can be separated from water is used. Good. Specifically, for example, benzene, toluene, xylene, ethylbenzene, trifluoromethylbenzene, chlorobenzene, anisole, benzonitrile, nitrobenzene, such as ethyl benzoate,
Benzene derivatives in which the benzene ring may be substituted with a halogen atom, an alkyl group, a haloalkyl group, an alkoxy group, a cyano group, a nitro group, a substituted oxycarbonyl group; an aliphatic hydrocarbon such as hexane, heptane, octane; Alicyclic hydrocarbons; haloalkanes such as carbon tetrachloride, chloroform, dichloromethane, and 1,2-dichloroethane; esters such as ethyl acetate; and linear or cyclic ethers such as diethyl ether and dibutyl ether. Preferred solvents include the above-mentioned benzene derivatives such as benzene, toluene, and trifluoromethylbenzene, haloalkanes such as 1,2-dichloroethane, and esters such as ethyl acetate. These solvents are used alone or in combination of two or more.

The derivation of the aldehyde into the oxime form is carried out by reacting the aldehyde with hydroxylamine. More specifically, for example, hydroxylamine salts (eg, hydrochloride, sulfate, phosphate, etc.)
A base (for example, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, etc.) is added to the aqueous solution of the above to prepare an aqueous solution of free hydroxylamine. Of the reaction solution, or filtration, concentration, dilution,
The aldehyde can be induced into an oxime form by adding a substance which has been subjected to treatments such as extraction and liquid property adjustment).

The oxime salt of the aldehyde is converted into a salt (oxime salt) by reacting the oxime obtained as described above with a base. Bases for forming oxime salts include hydroxides, carbonates, bicarbonates, alkali earth metal (eg, magnesium and calcium) hydroxides and carbonates of alkali metals (eg, sodium and potassium). An inorganic base such as is used.

The method for separating the aldehyde oxime or its salt is not particularly limited, and methods such as extraction and crystallization can be employed. In particular, when the aldehyde is converted to an oxime salt, a method of separating by an extraction operation using water and an organic solvent is preferable. According to this extraction method, the oxime salt of the aldehyde moves to the aqueous layer, and the unreacted substrate and reaction by-products move to the organic layer, so that the derivative can be separated efficiently.

The amount of the hydroxylamine to be used is 0.01 to 20 mol, preferably 0.5 to 5 mol, more preferably 1 to 1 mol, per mol of the aldehyde in the reaction mixture.
It is about 3 mol.

[Step (3)] In the step (3), the bisulfite adduct or oxime or its salt (oxime salt) is converted (reconverted) into an aldehyde. The bisulfite adduct can be converted to an aldehyde by hydrolysis using an acid or a base. In addition, the oxime form or a salt thereof is
It can be converted to aldehyde by hydrolysis using an acid.

As the acid used for the hydrolysis, hydrochloric acid,
Inorganic acids such as sulfuric acid, nitric acid and phosphoric acid; Examples of the base include hydroxides, carbonates, bicarbonates of alkali metals (eg, sodium, potassium, etc.), hydroxides, carbonates, bicarbonates of alkaline earth metals (eg, magnesium, calcium, etc.). Are used.

The acid or base is used in an amount of 0.01 to 20 mol, preferably 0.5 to 10 mol, more preferably 1 to 10 mol per mol of the bisulfite adduct or oxime or salt thereof used. About 3 mol. The hydrolysis temperature is, for example, 10 to 100 ° C, preferably 50 to 100 ° C.
The temperature is 100 ° C, more preferably 70 to 100 ° C.

The aldehyde formed by the conversion is, for example,
It can be extracted into an organic layer using an extraction solvent, and then recovered from the organic layer by operations such as concentration, crystallization, distillation, and flashing.

As the extraction solvent, the solvents listed as the solvent used for the extraction in the step (2) can be used. These solvents are used alone or in combination of two or more.

The extraction temperature can be appropriately selected according to the type of the solvent and the like, and is, for example, 0 to 200 ° C., preferably 20 to 200 ° C.
It is 150 ° C, more preferably about 70-100 ° C.

The aldehyde produced by the method of the present invention is useful as an intermediate for organic chemicals. For example, phthalaldehyde obtained from o-xylylene alcohol and / or phthalane can be used as a raw material of an industrial disinfectant, such as stearyl aldehyde obtained from stearyl alcohol, and palmitaldehyde obtained from palmitic alcohol (hexadecanol). Higher aldehydes can be used as raw materials for surfactants and the like.

[0094]

According to the present invention, alcohols (particularly 1,
4-diol, 1,5-diol, 1,6-diol,
Highly pure aldehydes can be efficiently produced from higher alcohols and / or ethers (particularly benzyl ethers and the like). Also, aldehydes can be industrially mass-produced.

[0095]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 15.2 kg of o-benzenedimethanol in a high pressure reactor,
2.3 kg of RuO ₂ and 136.8 kg of toluene are charged, and while stirring at 100 ° C. under a pressure of 2 MPa, air is blown at 12.3 m ³ (standard state) / hour and nitrogen is blown at 20.0 m.
^It was supplied at a flow rate of ³ (standard state) / hour for 5 hours. As a result of analyzing the product in the reaction mixture by gas chromatography, the conversion of o-benzenedimethanol was 100%, and o
-Selectivity and yield of phthalaldehyde were both 66%. In the reaction mixture, phthalide was by-produced at a yield of 18%. The reaction mixture was supplied to a catalyst separator, and the catalyst was separated by filtration at a temperature of 30 ° C. About 80% of the toluene present in the filtrate was flushed. 76.6 kg of a 20% by weight aqueous solution of NaHSO ₃ was added to the remaining liquid, and the mixture was stirred at a temperature of 30 ° C. for 1 hour to convert o-phthalaldehyde into an adduct of bisulfite. Next, the mixture was allowed to stand and separated, and 53.7 kg of a 10% by weight aqueous hydrochloric acid solution was charged into the aqueous layer, followed by stirring at 100 ° C. for 1 hour to carry out hydrolysis. Subsequently, 251.9 kg of toluene was charged and extracted with stirring at 100 ° C. for 1 hour. The organic layer was taken out, and toluene was distilled off to obtain 8.9 kg of o-phthalaldehyde having a purity of 96%.

Example 2 A reaction was carried out in the same manner as in Example 1, and the resulting reaction mixture was supplied to a catalyst separator, and the catalyst was separated by filtration at a temperature of 30 ° C. About 80% of the toluene present in the filtrate was flushed. Separately, 26.4 kg of a 10 wt% aqueous NaOH solution was added to 33.2 kg of a 20 wt% aqueous solution of hydroxylamine hydrochloride to prepare a hydroxylamine aqueous solution. The residual solution after the flash was charged into this aqueous hydroxylamine solution and stirred at 30 ° C. for 1 hour to oxime o-phthalaldehyde. Then 1
10 kg of a 0% by weight aqueous NaOH solution is charged,
After stirring for an hour, the oxime was converted to the oxime salt.
Thereafter, the mixture was allowed to stand and separated, and the aqueous layer was charged with 15 kg of a 10% by weight aqueous hydrochloric acid solution, followed by stirring at 100 ° C. for 1 hour for hydrolysis. Subsequently, 169.1 kg of toluene was charged and 1
Extraction was carried out with stirring at 00 ° C. for 1 hour, and the mixture was allowed to stand and separated. The organic layer was taken out, and toluene was distilled off to obtain 5.9 kg of o-phthalaldehyde having a purity of 95%.

Example 3 9.5 g of phthalane and a 60% aqueous nitric acid solution 1 were placed in a high-pressure reactor.
6.6 g, water 33.6 g and acetic acid 40.3 g were charged,
The reaction was carried out for 1 hour while stirring at 70 ° C. under normal pressure. The product in the reaction mixture was analyzed by gas chromatography. As a result, the conversion of phthalane was 100%, and the selectivity and the yield of o-phthalaldehyde were both 70%. In the reaction mixture, phthalide was by-produced in a yield of 14%.
The reaction mixture was charged with 200 g of toluene, extracted with stirring at 30 ° C., and separated by standing. The organic layer was removed and about 80% of the toluene was flushed. 20% by weight of Na
30 g of an aqueous solution of HSO ₃ was charged and stirred at 30 ° C. for 1 hour to convert o-phthalaldehyde to a bisulfite adduct. Next, the mixture was allowed to stand and separated, and the aqueous layer was charged with 20 g of a 10% by weight aqueous hydrochloric acid solution, and stirred at 90 ° C. for 1 hour to carry out hydrolysis. Subsequently, 200 g of toluene was charged, and 90 ° C.
Extraction was carried out with stirring for a period of time, followed by standing and liquid separation. The organic layer was taken out and toluene was distilled off to obtain 7 g of 96% pure o-phthalaldehyde.

Example 4 A reaction was carried out in the same manner as in Example 3, 200 g of toluene was added to the obtained reaction mixture, and the mixture was stirred and extracted at 30 ° C., followed by standing and separation. The organic layer was removed and about 80% of the toluene was flushed. Separately, a 20% by weight aqueous solution of hydroxylamine hydrochloride is added to 20 g of an aqueous solution of 10% by weight NaOH aqueous solution.
g was added to prepare an aqueous hydroxylamine solution. The residual solution after the flash was charged into this aqueous hydroxylamine solution and stirred at 30 ° C. for 1 hour to oxime o-phthalaldehyde. Then 10% by weight NaOH
An aqueous solution (10 g) was charged and the mixture was stirred at 30 ° C. for 1 hour to convert the oxime into an oxime salt. Then, the mixture was allowed to stand and separated, and 32 g of a 10% by weight aqueous hydrochloric acid solution was charged into the aqueous layer.
Hydrolysis was performed by stirring at 90 ° C. for 1 hour. Subsequently, 200 g of toluene was charged, and the mixture was stirred and extracted at 90 ° C. for 1 hour, followed by standing and liquid separation. The organic layer was taken out, and toluene was distilled off. As a result, 4.7% of o-phthalaldehyde having a purity of 95% was obtained.
g was obtained.

Example 5 A reactor was charged with 55 g of stearyl alcohol and 5% by weight of Ru /
80 g of C (dry product) and 500 g of ethylbenzene were added, and the mixture was stirred at a temperature of 95 ° C. under normal pressure, and air was added to 0.3 g.
The reaction was started by supplying 55 L (standard state) / min and nitrogen at a flow rate of 1.17 L (standard state) / min for 4 hours. During the reaction, after-produced water and ethylbenzene were distilled off, the distillate was separated by a decanter, the ethylbenzene layer was refluxed, and the water was discharged. As a result of analyzing the product in the reaction mixture by gas chromatography, the conversion of stearyl alcohol was 85%, and the selectivity and yield of stearyl aldehyde were 82% and 70%, respectively. In addition,
The reaction mixture contains 0.8% by weight of stearic acid and diacetal (aldehyde: alcohol = 1: 1 (molar ratio)).
1.0% by weight, and 0.4% by weight of triacetal (aldehyde: alcohol = 1: 2 (molar ratio)). The reaction mixture was supplied to a catalyst separator, and the catalyst was separated by filtration at a temperature of 70 ° C. About 80% of the ethylbenzene present in the filtrate was flushed. In this residual liquid,
80 g of a 20 wt% NaHSO ₃ aqueous solution was added, and
For 1 hour to convert stearyl aldehyde to a bisulfite adduct. Then, the mixture was allowed to stand and separated, and 1 μm was added to the aqueous layer.
60 g of a 0% by weight aqueous hydrochloric acid solution was added, and the mixture was stirred at 100 ° C. for 1 hour to perform hydrolysis. Then, ethylbenzene 270
g was added, and the mixture was extracted with stirring at 100 ° C. for 1 hour, and the mixture was allowed to stand and separated. The organic layer was taken out, and ethylbenzene was distilled off. As a result, 35.7% of stearylaldehyde having a purity of 96% was obtained.
g was obtained.

Example 6 A reaction was carried out in the same manner as in Example 5, and the obtained reaction mixture was supplied to a catalyst separator, and the catalyst was separated by filtration at a temperature of 70 ° C. About 80% of the toluene present in the filtrate was flushed. Separately, 50 g of a 20 wt% aqueous solution of hydroxylamine hydrochloride is added to 50 g of a 10 wt% aqueous NaOH solution.
By adding 0 g, an aqueous hydroxylamine solution was prepared.
The remaining solution after the flash was added to the aqueous hydroxylamine solution, and the mixture was stirred at 30 ° C. for 1 hour to oxime the stearylaldehyde. Then 10% by weight NaOH
20 g of an aqueous solution was added, and the mixture was stirred at 30 ° C. for 1 hour to convert the oxime into an oxime salt. After that, it is allowed to stand and separated,
30 g of a 10% by weight aqueous hydrochloric acid solution was added to the aqueous layer, and 10
Hydrolysis was carried out by stirring at 0 ° C. for 1 hour. Subsequently, 180 g of ethylbenzene was added, and the mixture was extracted with stirring for 1 hour, followed by standing and liquid separation. The organic layer was taken out, and ethylbenzene was distilled off to remove 95% pure stearyl aldehyde.
0 g was obtained.

Example 7 49 g of palmitic alcohol, 5% by weight of Ru /
80 g of C (dry product) and 500 g of ethylbenzene were charged, and while stirring at 95 ° C. under normal pressure, 0.35 of air was blown.
5 L (standard condition) / min and nitrogen were supplied at a flow rate of 1.17 L (standard condition) / min for 4 hours. After distilling off water and by-produced ethylbenzene during the reaction, the distillate was separated by a decanter, and the ethylbenzene layer was refluxed to discharge water. As a result of analyzing the product in the reaction mixture by gas chromatography, the conversion of palmitic alcohol was found to be 83%.
%, Palmitic aldehyde selectivity and yield were 81% and 67%, respectively. The reaction mixture contains
0.9% by weight of palmitic acid, 1.1% by weight of diacetal (aldehyde: alcohol = 1: 1 (molar ratio))
And triacetal (aldehyde: alcohol = 1: 2
(Molar ratio)) as a by-product of 0.3% by weight. The reaction mixture was supplied to a catalyst separator, and the catalyst was separated by filtration at a temperature of 70 ° C. About 80% of the ethylbenzene present in the filtrate was flushed. 20% by weight of NaH
75 g of SO ₃ aqueous solution was added and stirred at 30 ° C. for 1 hour,
Palmitaldehyde was converted to the bisulfite adduct. Next, the solution was allowed to stand and separated, 50 g of a 10% by weight aqueous hydrochloric acid solution was added to the aqueous layer, and the mixture was stirred at 90 ° C. for 1 hour for hydrolysis. Subsequently, 270 g of ethylbenzene was added, and the mixture was stirred and extracted at 90 ° C. for 1 hour, and left to stand for liquid separation. Take out the organic layer,
Ethylbenzene was distilled off to obtain 30.6 g of palmitic aldehyde having a purity of 95%.

Example 8 A reaction was carried out in the same manner as in Example 7, and the obtained reaction mixture was supplied to a catalyst separator, and the catalyst was separated by filtration at a temperature of 70 ° C. About 80% of the ethylbenzene present in the filtrate was flushed. Separately, 40 g of a 10% by weight aqueous NaOH solution was added to 50 g of a 20% by weight aqueous solution of hydroxylamine hydrochloride to prepare a hydroxylamine aqueous solution. The remaining solution after the flush was added to the aqueous hydroxylamine solution, and the mixture was stirred at 30 ° C. for 1 hour to oxime palmitaldehyde. Then 10 wt% N
20 g of an aOH aqueous solution was added, and the mixture was stirred at 30 ° C. for 1 hour.
The oxime was converted to an oxime salt. Thereafter, the solution was allowed to stand and separated, and 50 g of a 10% by weight aqueous hydrochloric acid solution was added to the aqueous layer. Subsequently, 180 g of ethylbenzene was added, and the mixture was extracted with stirring for 1 hour, followed by standing and liquid separation. The organic layer was taken out, and ethylbenzene was distilled off to obtain 20.6 g of palmitic aldehyde having a purity of 95%.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 47/02 C07C 47/02 47/544 47/544 // C07B 61/00 300 C07B 61/00 300 F Term (reference) 4H006 AA02 AC45 AD16 AD30 AD33 BA23 BA30 BA55 BB10 BB31 BE02 BE30 BE63 4H039 CA65 CC20 CH70

Claims (9)

[Claims] 1. A method for producing a corresponding aldehyde by oxidizing an alcohol and / or ether, comprising the steps of (1)
An oxidation step of oxidizing alcohol and / or ether,
(2) a method for producing an aldehyde comprising the steps of: deriving an aldehyde generated in the oxidation step into a bisulfite adduct or an oxime or a salt thereof and separating the derivative; and (3) converting the derivative to an aldehyde. . 2. The method for producing an aldehyde according to claim 1, wherein the ether has a methylene group at both positions adjacent to an oxygen atom constituting an ether bond. 3. The method for producing an aldehyde according to claim 1, further comprising (4) a catalyst recovery step of recovering the catalyst from the reaction mixture. 4. In the step (2), after the generated aldehyde is induced into a bisulfite adduct, the bisaldehyde is subjected to an extraction operation using water and an organic solvent to recover the bisulfite adduct from the aqueous layer. 2. The aldehyde production according to claim 1, wherein in the step (3), the bisulfite adduct is converted into an aldehyde by hydrolysis with an acid or a base, and then subjected to an extraction operation using water and an organic solvent. Method. 5. In the step (2), after the generated aldehyde is converted to an oxime salt, the oxime salt is subjected to an extraction operation using water and an organic solvent to recover the oxime salt from the aqueous layer, and the step (3). The method according to claim 1, wherein the oxime salt is converted into an aldehyde by hydrolyzing the oxime salt with an acid. 6. The alcohol is 1,4-diol, 1,5
The method for producing an aldehyde according to claim 1, which is -diol or 1,6-diol. 7. The method for producing an aldehyde according to claim 1, wherein the alcohol is o-benzenedimethanol. 8. The method for producing an aldehyde according to claim 1, wherein the alcohol is an aliphatic primary alcohol having 12 to 20 carbon atoms. 9. The method for producing an aldehyde according to claim 1, wherein the ether is benzyl ether.