JP5580075B2 - Method for producing amide compound - Google Patents

Description

  The present invention relates to a method for producing an amide compound by Beckmann rearrangement reaction of an oxime compound.

  As an industrial method for producing an amide compound, there is a method in which an oxime compound is converted to an amide compound by Beckmann rearrangement reaction. For example, a method of producing ε-caprolactam by carrying out Beckmann rearrangement reaction of cyclohexanone oxime using strong acid such as concentrated sulfuric acid or fuming sulfuric acid in a liquid phase is known. However, this method has a problem that a large amount of ammonium sulfate is produced as a by-product because an aqueous ammonia solution is used in the neutralization step when separating ε-caprolactam from the reaction product solution.

  In order to solve such problems, various catalysts used for Beckmann rearrangement reactions have been studied. For example, a catalyst (non-patent document 1) consisting of an ion pair (Vilsmeier complex) generated from N, N-dimethylformamide and chlorosulfonic acid, an alkylation generated from an epoxy compound and a strong acid (such as boron trifluoride / etherate) And a catalyst comprising N, N-dialkylformamide (Non-patent Document 2), a catalyst comprising phosphoric acid or a condensable phosphoric acid compound (Patent Document 1), a compound such as N, N-dialkylformamide, phosphorus pentoxide, In addition, a catalyst made of a strong fluorine-containing acid or a derivative thereof (Patent Document 2), an indium triflate (Non-Patent Document 3), a ytterbium triflate (Non-Patent Document 4), and the like are known.

Japanese Patent Laid-Open No. Sho 62-149665 JP-A-5-105654

M.M. A. Kira, et. al. , Egypt. J. et al. Chem. , Vol. 16, pp. 551-553 (1973) Y. Izumi, Chemistry Letters, pp. 2171-2174 (1990) J. et al. S. Sandhu, et. al. , Indian Journal of Chemistry, pp. 154-156 (2002) J. et al. S. Yadav, et. al. , Journal of Chemical Research (S), pp. 236-238 (2002)

  However, in particular, the Beckmann rearrangement reaction of cyclohexanone oxime does not proceed easily, and there is a need for a solution. Therefore, the present invention provides a method for producing an amide compound capable of producing an amide compound in a high yield by suppressing the formation of by-products in a method for producing an amide compound by subjecting an oxime compound to a Beckmann rearrangement reaction. Objective. In particular, an object of the present invention is to provide a method for producing ε-caprolactam with high yield by suppressing the formation of by-products from cyclohexanone oxime.

  In order to achieve the above object, as a result of intensive research, the present inventors have determined that at least one of the first catalyst of acid chloride, acid anhydride, and Lewis acid and the nitrogen atom of the oxime compound. By performing the Beckmann rearrangement reaction in the presence of a second catalyst comprising an interactable compound (excluding those specifically selected in the first catalyst), the production of by-products is suppressed and high yield is achieved. It has been found that amide compounds can be produced at a high rate. That is, the present invention provides a method for producing an amide compound by subjecting an oxime compound to a Beckmann rearrangement reaction, wherein at least one of an acid chloride, an acid anhydride, and a Lewis acid, and a nitrogen of the oxime compound. A method for producing an amide compound, characterized by carrying out a Beckmann rearrangement reaction in the presence of a second catalyst comprising a compound capable of interacting with an atom (excluding those specifically selected in the first catalyst). .

  As described above, according to the present invention, it is possible to provide a method for producing an amide compound capable of producing an amide compound in a high yield while suppressing the production of by-products.

  The oxime compound used in the present invention is not particularly limited and can be appropriately selected depending on the amide compound to be produced. As an oxime compound, the compound represented by following formula (1) is mentioned, for example.

In formula (1), R ¹ and R ² each represents an organic group. R ¹ and R ² may be a divalent organic group bonded to each other to form a ring.

Examples of the organic group in R ¹ and R ² include alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, aryl groups, aralkyl groups, and heterocyclic groups.

  As an alkyl group, a C1-C20 alkyl group is mentioned, for example, It is preferable that it is a C1-C12 alkyl group, and it is more preferable that it is a C2-C8 alkyl group. . Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, isopentyl, hexyl, isohexyl, and heptyl. Group, octyl group, nonyl group, decyl group, dodecyl group, pentadecyl group and the like.

  Examples of the alkenyl group include alkenyl groups having 2 to 20 carbon atoms, preferably alkenyl groups having 2 to 12 carbon atoms, and more preferably alkenyl groups having 2 to 8 carbon atoms. . Specific examples of the alkenyl group include a vinyl group, an allyl group, a 1-propenyl group, a 1-butenyl group, a 1-pentenyl group, and a 1-octenyl group.

  Examples of the alkynyl group include alkynyl groups having 2 to 20 carbon atoms, preferably alkynyl groups having 2 to 12 carbon atoms, and more preferably alkynyl groups having 2 to 8 carbon atoms. . Specific examples of the alkynyl group include ethynyl group and 1-propynyl group.

  Examples of the cycloalkyl group include a cycloalkyl group having 3 to 20 carbon atoms, and a cycloalkyl group having 3 to 15 carbon atoms is preferable. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclododecyl group.

  As a cycloalkenyl group, a C3-C20 cycloalkenyl group is mentioned, for example, It is preferable that it is a C3-C15 cycloalkenyl group. Specific examples of the cycloalkenyl group include a cyclopentenyl group, a cyclohexenyl group, and a cyclooctenyl group.

  As an aryl group, a C6-C24 aryl group is mentioned, for example. Specific examples of the aryl group include a phenyl group and a naphthyl group.

  Examples of the aralkyl group include aralkyl groups having 7 to 25 carbon atoms. Specific examples of the aralkyl group include a benzyl group, a 2-phenylethyl group, and a 3-phenylpropyl group.

  As a heterocyclic group, an aromatic heterocyclic group and a non-aromatic heterocyclic group are mentioned, for example, It is preferable that it is a C1-C24 heterocyclic group. Specific examples of the heterocyclic group include a 2-pyridyl group, a 2-quinolyl group, a 2-furyl group, a 2-thienyl group, and a 4-piperidinyl group.

When R ¹ and R ² are an organic group bonded to each other to form a ring, examples of the divalent organic group include a linear or branched alkylene group, and a linear alkylene group is preferable. . The alkylene group preferably includes a 3- to 30-membered ring including the carbon atom of the oxime compound represented by the formula (1), more preferably a 4- to 20-membered ring, It is particularly preferred that a 5-14 membered ring is formed. Specific examples of the divalent alkylene group include an ethylene group, a trimethylene group, and a propylene group.

  The organic group is not particularly limited as long as it does not inhibit the Beckmann rearrangement reaction, and may have various substituents. Examples of the substituent include a halogen atom, oxo group, mercapto group, alkoxy group, aryloxy group, acyloxy group, alkylthio group, arylthio group, heteroarylthio group, oxycarbonyl group, carbamoyl group, cyano group, nitro group, Examples include an aminoalkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a heteroaryl group, an aralkyl group, and a heterocyclic group.

In formula (1), examples of the oxime compound in which R ¹ and R ² are each an organic group include acetone oxime, 2-butanone oxime, 2-pentanone oxime, 3-pentanone oxime, and 1-cyclohexyl-1 -Propanone oxime, acetophenone oxime, p-methoxyacetophenone oxime, o-methoxyacetophenone oxime, p-fluoroacetophenone oxime, benzophenone oxime, and 4-hydroxyacetophenone oxime. Examples of the oxime compound in which R ¹ and R ^{2 in} formula (1) are divalent organic groups bonded to each other to form a ring include, for example, cyclopropanone oxime, cyclobutanone oxime, cyclohexanone oxime, cycloheptanone Oxime, cyclooctanone oxime, cyclononanone oxime, cyclodecanone oxime, cyclododecanone oxime, cyclotridecanone oxime, cyclotetradecanone oxime, cyclopentadecanone oxime, cyclohexadecanone oxime, cyclooctadecanone oxime, And cyclononadecanone oxime. Among these oxime compounds, cyclododecanone oxime, cyclohexanone oxime, acetophenone oxime, p-methoxyacetophenone oxime, o-methoxyacetophenone oxime, and p-fluoroacetophenone oxime are preferable, and cyclohexanone oxime is more preferable. . One or more oxime compounds can be selected and used.

  The oxime compound can be obtained by reacting a ketone corresponding to the oxime compound represented by the formula (1) with hydroxylamine. For example, cyclododecanone oxime can be obtained by reacting cyclododecanone and hydroxylamine sulfate as described in JP-B-51-46109.

  The oxime compound is an N-hydroxyimide compound derived from an aliphatic polyvalent carboxylic acid anhydride or an aromatic polyvalent carboxylic acid anhydride, or a protective group (for example, acetyl group) on the hydroxyl group of the N-hydroxyimide compound. It can also be obtained by reacting a compound having a methyl group or a methylene group with a nitrite or nitrite in the presence of a compound obtained by introducing an acyl group such as a group. Examples of the aliphatic polycarboxylic anhydride or aromatic polycarboxylic anhydride include N-hydroxysuccinimide, N-hydroxyphthalimide, N, N′-dihydroxypyromellitic diimide, and N-hydroxy. Mention may be made of glutarimide, N-hydroxy-1,8-naphthalenedicarboxylic acid imide, and N, N′-dihydroxy-1,3,4,5-naphthalenetetracarboxylic acid diimide.

  In the present invention, the first catalyst is a catalyst composed of at least one of acidic chloride, acid anhydride, and Lewis acid. Examples of acidic chlorides include sulfur chlorides such as thionyl chloride, sulfuryl chloride, chlorosulfonic acid, benzenesulfonyl chloride, p-toluenesulfonyl chloride, and methanesulfonyl chloride; phosphorus trichloride, phosphorus pentachloride, and phosphorus oxychloride Inorganic phosphorous chlorides such as; chlorocarbonates such as methyl chlorocarbonate, ethyl chlorocarbonate, phenyl chlorocarbonate, and benzyl chlorocarbonate; carbonic acid or carboxylic acid such as formic acid chloride, acetyl chloride, benzoyl chloride, phosgene, and oxalyl chloride And borate chlorides such as boron trichloride, sulfur chloride is preferable, thionyl chloride and methanesulfonyl chloride are more preferable, and thionyl chloride is particularly preferable.

  Examples of the acid anhydride include aliphatic carboxylic acid anhydrides, aromatic carboxylic acid anhydrides, sulfonic acid anhydrides, and phosphoric acid anhydrides. Examples of the aliphatic carboxylic acid anhydride include linear aliphatic carboxylic acid anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, and cyclohexyl acetic anhydride, and maleic anhydride, Examples thereof include aliphatic carboxylic acid anhydrides that have been cyclized by intramolecular dehydration, such as succinic anhydride and cyclohexanedicarboxylic acid anhydride. Examples of the aromatic carboxylic acid anhydride include phthalic anhydride and benzoic anhydride. Examples of the sulfonic acid anhydride include trifluoromethanesulfonic acid anhydride, methanesulfonic acid anhydride, and p-toluenesulfonic acid anhydride. Examples of phosphoric anhydride include dimethylphosphinic anhydride, methylpropylphosphinic anhydride, dicyclohexylphosphinic anhydride, and diphenylphosphinic anhydride. Of these, sulfonic anhydride is preferable, and trifluoromethanesulfonic anhydride is more preferable.

  Examples of Lewis acids include metal halides such as zinc chloride, iron chloride, cobalt chloride, tin chloride, aluminum chloride, and titanium chloride; boron halide compounds such as boron trifluoride; and ytterbium triflate, samarium triflate, Mention may be made of triflate compounds such as lanthanum triflate and yttrium triflate. Among these, triflate compounds are preferable, lanthanoid triflates and yttrium triflates are more preferable, and ytterbium triflates, samarium triflates, lanthanum triflates, and yttrium triflates are particularly preferable.

  The first catalyst is preferably at least one of sulfur chloride and triflate compounds.

  In the present invention, the second catalyst may be a compound that can interact with the nitrogen atom of the oxime compound. Here, the nitrogen atom is N in the formula (1) in the case of the oxime compound represented by the formula (1). Examples of the interaction include a coordinate bond between a nitrogen atom and a compound. The compound capable of interacting is preferably a metal salt capable of interacting with the oxime compound, and more preferably a metal salt capable of coordinating with the nitrogen atom of the oxime compound. As a metal salt capable of interacting with an oxime compound, a metal capable of interaction such as formation of a complex by coordination of nitrogen of the oxime compound represented by formula (1) with a focus on the metal contained in the metal salt. Examples of such metal salts include nickel salts and cobalt salts. Examples of the nickel salt include nickel bromide. Examples of the cobalt salt include cobalt nitrate, cobalt chloride, cobalt perchlorate, cobalt borofluoride, and hydrates thereof. The hydrate is preferably cobalt nitrate hexahydrate, cobalt perchlorate hexahydrate, cobalt borofluoride hexahydrate, cobalt nitrate hexahydrate, cobalt perchlorate hexahydrate. More preferably, it is a cobalt perchlorate hexahydrate.

  The second catalyst is specifically selected as the first catalyst, and the same catalyst is not selected for the first catalyst and the second catalyst. For example, when cobalt chloride is selected as the first catalyst, a catalyst other than cobalt chloride is selected as the second catalyst. Conversely, when cobalt chloride is selected as the second catalyst, a catalyst other than cobalt chloride is selected as the first catalyst.

  The amount of the acid chloride used is preferably 0.001 to 100 mol, more preferably 0.001 to 1.0 mol, per mol of the oxime compound.

  The amount of the acid anhydride used is preferably 0.001 to 100 mol, more preferably 0.001 to 1.0 mol, per mol of the oxime compound.

  The amount of Lewis acid used is preferably 0.001 to 100 mol, more preferably 0.001 to 1.0 mol, per mol of the oxime compound.

  The amount of the second catalyst used is preferably 0.001 to 100 mol, more preferably 0.01 to 1.0 mol, per mol of the oxime compound.

  In the present invention, the Beckmann rearrangement reaction can be performed without solvent or in the presence of a solvent. When a solvent is used, the solvent is not particularly limited as long as it does not inhibit the reaction. For example, aromatic hydrocarbons such as benzene, toluene, xylene, cumene, and chlorobenzene; n-hexane, n-heptane , N-octane, n-nonane, cyclohexane, cyclooctane, cyclodecane, cyclododecane, hydrocumene and other aliphatic hydrocarbons; acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, cyclododecanone, etc. Ketones; Nitriles such as acetonitrile, propionitrile, and benzonitrile; formamide, acetamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazoli Amides such as dimethyl sulfoxide; Sulfoxides such as dimethyl sulfoxide and sulfolane; Sulfones; Esters such as ethyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl butanoate; Formic acid, acetic acid, propionic acid, Carboxylic acids such as butanoic acid and trifluoroacetic acid; ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, and dioxane; phosphoric acid amides such as hexamethylphosphoric triamide; chloroform, dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene And halogenated hydrocarbons such as trifluoromethylbenzene; nitro compounds such as nitrobenzene, nitromethane, and nitroethane; and hexafluoroisopropyl alcohol, trifluoroethanol, and the like Mention may be made of a fluorine-based alcohol. Among these, nitriles, aromatic hydrocarbons, carboxylic acids, and fluorinated alcohols are preferable, and acetonitrile is more preferable. A solvent can also be used independently and may mix 2 or more types of solvents.

  Although the usage-amount of a solvent is not specifically limited, It is preferable that it is 0-100 weight times of an oxime compound, and it is more preferable that it is 1-50 weight times.

  The Beckmann rearrangement reaction conditions can be appropriately selected depending on the type and amount of the oxime compound, catalyst, solvent and the like to be used, and are not particularly limited. In general, the reaction temperature is preferably 20 to 120 ° C. The reaction pressure can be carried out under normal pressure or pressurized conditions. The reaction may be performed in an inert gas atmosphere such as nitrogen or argon, or may be performed in an air or oxygen atmosphere. In general, the reaction time is preferably 0.01 to 24 hours, and more preferably 0.05 to 20 hours. As the reaction apparatus, a reactor equipped with a normal stirring apparatus can be used.

In the method for producing an amide compound according to the present invention, in the formula (1), when R ¹ and R ² are each an organic group oxime compound, Beckmann rearrangement does not include an amide bond portion in a cyclic form. An amide compound is obtained. For example, acetanilide is obtained from acetophenone oxime. When an oxime compound, which is a divalent organic group in which R ¹ and R ² are bonded to each other to form a ring, undergoes Beckmann rearrangement, a lactam is obtained. For example, cycloalkanone oxime provides a lactam having one more member ring. Specifically, ε-caprolactam is from cyclohexanone oxime, 7-heptane lactam is from cycloheptanone oxime, 8-octane lactam is from cyclooctanone oxime, and laurolactam is from cyclododecanone oxime. Is obtained.

  After completion of the Beckmann rearrangement reaction, the obtained amide compound may be separated and purified by separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, adsorption, or column chromatography, or a combination thereof. Good.

  For example, as separation and purification after the Beckmann rearrangement reaction of cyclododecanone oxime, laurolactam is obtained by adding water to the obtained laurolactam-containing material, extracting with an organic solvent, and then distilling off the solvent. Can do. Furthermore, it may be separated and purified by distillation, crystallization or the like.

Example 1
In a threaded test tube, cyclohexanone oxime (56.6 mg, 0.5 mmol), thionyl chloride (3.6 μl, 0.05 mmol), cobalt nitrate hexahydrate (7.3 mg, 0.025 mmol), and 1.0 ml of acetonitrile. And stirred in an oil bath at 80 ° C. for 20 hours to obtain a green liquid. The resulting reaction mixture was treated with 2.0 ml of saturated aqueous sodium hydrogen carbonate solution and dried over magnesium sulfate. Magnesium sulfate was filtered and the solvent was distilled off to obtain 40.8 mg of a brown solid. The composition ratio was determined by ¹ H-NMR analysis. As a result, ε-caprolactam was 64.7 mol% and cyclohexanone was 3.7 mol%.

(Example 2)
Put a hexahexanone oxime (56.6 mg, 0.5 mmol), nickel bromide (108.8 mg, 0.025 mmol), ytterbium triflate (15.8 mg, 0.025 mmol), and 1.0 ml of acetonitrile in a threaded test tube. The mixture was stirred in an oil bath at 80 ° C. for 2 hours to obtain a green liquid. The resulting reaction mixture was treated with 2.0 ml of saturated aqueous sodium hydrogen carbonate solution and dried over magnesium sulfate. Magnesium sulfate was filtered and the solvent was distilled off to obtain 36.3 mg of a brown solid. The composition ratio was determined by ¹ H-NMR analysis. As a result, ε-caprolactam was 62.6 mol% and cyclohexanone was 37.4 mol%.

Example 3
Cyclohexanone oxime (56.6 mg, 0.5 mmol), cobalt nitrate hexahydrate (145.5 mg, 0.5 mmol), ytterbium triflate (15.8 mg, 0.025 mmol), and 1.0 ml of acetonitrile in a threaded test tube And stirred in an oil bath at 80 ° C. for 20 hours to obtain a brown liquid. The obtained reaction mixture was diluted with ethyl acetate (10 ml), 0.4 M aqueous sodium hydroxide solution (2 ml) saturated with sodium chloride was added and stirred well, and then concentrated under reduced pressure until dryness. Dichloromethane (50 ml) was added to the residue and stirred well, and the insoluble matter was filtered off and washed (dichloromethane 50 ml). The filtrate and washings were combined and concentrated under reduced pressure to obtain 53.1 mg of a brown liquid. ^{According to 1} H-NMR analysis, only ε-caprolactam was found.

Example 4
In a test tube with a screw, cyclohexanone oxime (56.6 mg, 0.5 mmol), cobalt borofluoride hexahydrate (85.1 mg, 0.25 mmol), trifluoromethanesulfonic anhydride (14.1 mg, 0.05 mmol), Then, 1.0 ml of acetonitrile was added and stirred in an oil bath at 80 ° C. for 2 hours to obtain a brown liquid. The obtained reaction mixture was subjected to base treatment with 2.0 ml of a 0.4 M aqueous sodium hydroxide solution saturated with sodium chloride and dried over magnesium sulfate. Magnesium sulfate was filtered and the solvent was distilled off to obtain 28.1 mg of a brown liquid. ^{According to 1} H-NMR analysis, only ε-caprolactam was found.

(Example 5)
In a threaded test tube cyclohexanone oxime (56.6 mg, 0.5 mmol), cobalt borofluoride hexahydrate (17.0 mg, 0.05 mmol), samarium triflate (29.9 mg, 0.05 mmol), and acetonitrile. 0 ml was added and stirred in an oil bath at 80 ° C. for 2 hours to obtain a brown liquid. The resulting reaction mixture was treated with 2.0 ml of saturated aqueous sodium hydrogen carbonate solution and dried over magnesium sulfate. Magnesium sulfate was filtered and the solvent was distilled off to obtain 33.3 mg of a brown liquid. The composition ratio was determined by ¹ H-NMR analysis. As a result, ε-caprolactam was 52.6 mol% and cyclohexanone 6.2 mol%.

(Example 6)
In a threaded tube, cyclohexanone oxime (56.6 mg, 0.5 mmol), thionyl chloride (3.6 μl, 0.05 mmol), cobalt perchlorate hexahydrate (9.6 mg, 0.025 mmol), and acetonitrile 1 0.0 ml was added and stirred in an oil bath at 80 ° C. for 20 hours to obtain a brown liquid. The resulting reaction mixture was treated with 2.0 ml of saturated aqueous sodium hydrogen carbonate solution and dried over magnesium sulfate. Magnesium sulfate was filtered and the solvent was distilled off to obtain 46.7 mg of a brown solid. The composition ratio was determined by ¹ H-NMR analysis. As a result, ε-caprolactam was 53.7 mol%, cyclohexanone 4.7 mol%, and cyclohexanone oxime 41.6 mol%.

  The catalysts used in Examples 1 to 6 are shown in Table 1.

Claims (2)

In a method for producing an amide compound by subjecting an oxime compound to a Beckmann rearrangement reaction,
A method for producing an amide compound, characterized by causing Beckmann rearrangement reaction in the presence of thionyl chloride and cobalt perchlorate hexahydrate . 2. The amide compound according to claim 1, wherein the oxime compound is cyclododecanone oxime, cyclohexanone oxime, acetophenone oxime, p-methoxyacetophenone oxime, o-methoxyacetophenone oxime, or p-fluoroacetophenone oxime. Method.