WO2015015804A1 - Method for producing 1-alkylimidazole compound - Google Patents

Abstract

The present invention relates to a method for producing a 1-alkylimidazole compound which, under the presence of a catalyst comprising copper and chrome, subjects a vicinal diol compound, formaldehyde, ammonia, and a primary amine compound or a primary alcohol compound to a vapor phase catalytic reaction. According to the present invention, the method for producing a 1-alkylimidazole compound with high yield can be provided by a vapor phase catalytic reaction using a vicinal diol compound, formaldehyde, ammonia, and a primary amine compound or a primary alcohol compound as raw materials.

Description

Method for producing 1-alkylimidazole compound

The present invention relates to a process for producing a 1-alkylimidazole compound, characterized by subjecting a vicinal diol compound, formaldehyde, ammonia and a primary amine compound or primary alcohol compound to a gas phase catalytic reaction in the presence of a catalyst containing copper and chromium. .

1-Alkylimidazole compounds are compounds useful as intermediates for pharmaceuticals, agricultural chemicals, functional materials, etc., and for producing ionic liquids that have recently attracted attention as recyclable solvents in the field of green chemistry. It is a compound useful as a raw material.

As a method for producing a 1-alkylimidazole compound, a method of vapor phase catalytic reaction of ethylene glycol, formaldehyde, ammonia and methylamine in the presence of a 7 wt% Pb / H-MFI type zeolite catalyst has already been reported, and the yield is 28% In 1-methylimidazole (see Patent Document 1).

JP 2013-119524 A

However, the conventional production method has a low yield of 1-alkylimidazole compound as low as 28%, and is not satisfactory as a production method of 1-alkylimidazole compound in terms of yield.

As a result of intensive investigations in view of the problems of the conventional production method, the present inventors have made vapor phase contact of a vicinal diol compound, formaldehyde, ammonia and a primary amine compound or primary alcohol compound in the presence of a catalyst containing copper and chromium. As a result of the reaction, it was found that a 1-alkylimidazole compound can be produced in good yield, and the present invention has been completed.

That is, the present invention provides a 1-alkylimidazole compound characterized by reacting a vicinal diol compound, formaldehyde, ammonia and a primary amine compound or primary alcohol compound in a gas phase in the presence of a catalyst containing copper and chromium. It relates to the manufacturing method.

According to the present invention, a 1-alkylimidazole compound can be produced in a high yield by a gas phase catalytic reaction using a vicinal diol compound, formaldehyde, ammonia and a primary amine compound or primary alcohol compound as raw materials. Therefore, the present invention is industrially useful.

Hereinafter, the present invention will be described in detail. As the vicinal diol compound used in the present invention, the formula (1):

（式中、Ｒ^１およびＲ^２は、水素原子、炭素数１～８のアルキル基または炭素数５～８のシクロアルキル基である。）
で示されるビシナルジオール化合物（以下、ビシナルジオール（１）という）が挙げられる。

(In the formula, R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms.)
And a vicinal diol compound (hereinafter referred to as vicinal diol (1)).

In the formula (1), R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, More preferably, it is a hydrogen atom. Specific examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, An octyl group etc. are mentioned. Examples of the cycloalkyl group having 5 to 8 carbon atoms include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

As the primary amine compound, the formula (2):

（式中、Ｒ^３は炭素数１～８のアルキル基または炭素数５～８のシクロアルキル基を表す。）
で示される第一級アミン（以下、アミン（２）という）が挙げられる。

(In the formula, R ³ represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms.)
And a primary amine (hereinafter referred to as amine (2)).

In the formula (2), R ³ is an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. Specific examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, An octyl group etc. are mentioned. Examples of the cycloalkyl group having 5 to 8 carbon atoms include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

As the primary alcohol compound, the formula (3):

（式中、Ｒ^３は前記と同じ。）
で示される第一級アルコール（以下、アルコール（３）という）が挙げられる。

(In the formula, R ³ is the same as above.)
Primary alcohol (hereinafter referred to as alcohol (3)).

The 1-alkylimidazole compound produced according to the present invention has the formula (4):

（式中、Ｒ^１～Ｒ^３は前記に同じ。）
で示される１－アルキルイミダゾール化合物（以下、１－アルキルイミダゾール（４）という）である。

(Wherein R ¹ to R ³ are the same as above)
A 1-alkylimidazole compound (hereinafter referred to as 1-alkylimidazole (4)).

The formaldehyde used in the present invention is usually an aqueous solution containing 30 to 50% by weight of formaldehyde, but paraformaldehyde or 1,3,5-trioxane may be used in addition to the aqueous solution. In addition, the ammonia used in the present invention is not particularly limited as long as it is industrially available.

As the catalyst containing copper and chromium used in the present invention, a catalyst containing copper and chromium; a catalyst containing copper, chromium and a metal belonging to Group 7 of the periodic table; copper, chromium and periodic table No. 11 Catalysts containing metals belonging to the group (excluding copper); from the group consisting of catalysts containing copper, chromium, metals belonging to group 7 of the periodic table and metals belonging to group 11 of the periodic table (excluding copper) There may be mentioned at least one catalyst selected. In addition to the metal, the catalyst containing copper and chromium includes metals belonging to Group 8 of the periodic table (iron, ruthenium and osmium), metals belonging to Group 9 of the periodic table (cobalt, rhodium and iridium) and the period. It may contain at least one metal selected from metals (nickel, palladium and platinum) belonging to Group 10 of the Table. Specifically, it comprises a catalyst containing copper, chromium and manganese; a catalyst containing copper, chromium and barium; a catalyst containing copper, chromium, manganese and barium: a catalyst containing copper, chromium, manganese and silver Examples include at least one catalyst selected from the group. More specifically, a copper-chromium catalyst, a copper-chromium-manganese catalyst, a copper-chromium-barium catalyst, a copper-chromium-manganese-barium catalyst, a copper-chromium-manganese-silver catalyst, and a copper-chromium catalyst Copper-chromium-manganese catalysts, copper-chromium-manganese-barium catalysts, and copper-chromium-manganese-silver catalysts are preferred. The metal contained in the catalyst may be in any form of a simple metal or a metal compound (oxide, hydroxide, metal salt, etc.).

The content ratio of copper and chromium in the catalyst containing copper and chromium used in the present invention is such that the weight ratio of copper to the weight of chromium is 0.05 to 20 in terms of the ratio of copper to chromium alone. Preferably, it is 0.1 to 10, more preferably 0.5 to 2. The content of metals other than copper and chromium contained in the catalyst is not particularly limited, but is preferably 0.01 to 50% by weight, more preferably 0.5 to 20% by weight. In particular, when the catalyst contains silver, the silver content is usually 1 to 10% by weight, preferably 3 to 8% by weight, more preferably 5 to 7.5% by weight.

Commercially available products may be used as the catalyst containing copper and chromium used in the present invention, and those prepared by the following method may be used. The method for preparing the catalyst used in the present invention is not particularly limited, and a kneading method, an impregnation method, a coprecipitation method, an ion exchange method, a concentration to dryness method, or the like is used. The catalyst preparation method will be described in detail. For example, when preparing a catalyst having a metal supported on a support by an impregnation method, the catalyst preparation raw material is dissolved in a solvent such as water, and the resulting solution is impregnated on the support. And let it dry. Next, a method of firing at 250 to 700 ° C. in an air stream is mentioned.

The catalyst containing copper and chromium used in the present invention is used after being formed into a desired shape such as powder, columnar, cylindrical, spherical, or granular.

The catalyst containing copper and chromium used in the present invention is preferably used after being subjected to a reduction treatment before being used in the gas phase catalytic reaction of the present invention. Although it does not restrict | limit especially as a reducing agent used for a reduction process, Hydrogen is preferable. The hydrogen may be diluted with an inert gas such as nitrogen or argon. The method for reducing the catalyst is not particularly limited, but heat treatment under hydrogen flow is preferable. The reduction temperature with hydrogen is usually 50 to 500 ° C., preferably 75 to 450 ° C., more preferably 125 to 375 ° C., and further preferably 150 to 350 ° C. The hydrogen flow rate (space velocity, SV) in the reduction treatment is usually SV = 1 to 1500 / hr, preferably SV = 50 to 500 / hr, and more preferably SV = 100 to 200 / hr.

The reaction temperature in the gas phase contact reaction of the present invention is usually 100 to 500 ° C., preferably 150 to 450 ° C., more preferably 250 to 325 ° C., and further preferably 250 to 300 ° C. The reaction pressure in the gas phase contact reaction is normal pressure or pressurization. The reaction method of the gas phase contact reaction is not particularly limited, and the reaction is performed in a fixed bed, a fluidized bed, or a moving bed, and any of a batch method and a continuous method can be adopted.

The amount of the raw material used in the present invention is usually a molar ratio of vicinal diol (1): formaldehyde: ammonia: amine (2), usually 1: 0.1-20.0: 0.1-50. 0: 0.1 to 20.0, preferably 1: 0.5 to 10.0: 0.5 to 20.0: 0.5 to 10.0. The molar ratio of vicinal diol (1): formaldehyde: ammonia: alcohol (3) is usually 1: 0.1-20.0: 0.1-50.0: 0.1-20.0, Preferably, it is 1: 0.5 to 10.0: 0.5 to 20.0: 0.5 to 10.0.

The flow rate of the visual diol (1) is usually 0.01 to 2 (g / cc-catalyst · h) in terms of LHSV (liquid space velocity), preferably 0.1 to 1 (g / cc-catalyst · h).

The gas phase contact reaction is performed in the presence or absence of a diluent. The diluent is not particularly limited as long as it is inert to the reaction, and any diluent can be used. Specifically, an inert gas such as nitrogen and argon, an aliphatic hydrocarbon such as hexane, heptane, octane, nonane, decane, and undecane can be used. These may be used alone or in combination of two or more.

After completion of the gas phase contact reaction, the product is collected by an appropriate means such as absorbing the generated reaction gas into water or an organic solvent, and then the absorption liquid containing the obtained product is subjected to normal purification such as distillation. By the means, the target 1-alkylimidazole (4) can be obtained. Water is preferably used as the absorbent that absorbs the reaction gas.

Next, the present invention will be specifically described based on examples, but the present invention is not limited thereto. The gas chromatography analysis conditions in the examples are as follows. The conversion rate and yield were calculated according to the following definitions.

Conversion (%) = reacted vicinal diol (1) (mol) / feed vicinal diol (1) (mol) × 100
Yield (%) = 1-alkylimidazole produced by the reaction (4) (mol) / supplied vicinal diol (1) (mol) × 100

Gas chromatography analysis conditions Gas chromatograph: GC-2010 manufactured by Shimadzu Corporation
Column: DB-WAX (30 m, inner diameter 0.32 mm, film thickness 0.25 μm), manufactured by Agilent Technologies
Carrier gas: helium, linear velocity: 36.1 cm / min
Split ratio: 1:50
Vaporization chamber temperature: 250 ° C
Column temperature: 50 ° C. (3 min) → (15 ° C./min)→200° C. (0 min) → (20 ° C./min)→250° C. (9.5 min),
Detector: FID (hydrogen flame ionization detector)
Detector temperature: 280 ° C

Example 1
1-1. Catalyst reduction treatment step A Pyrex (registered trademark) reaction tube having an inner diameter of 19 mm was filled with 15 ml of T-4466 catalyst (Cu: 42 wt%, Cr: 31 wt%) manufactured by Clariant Catalyst Co., Ltd. Carborundum was filled with a length of 22 cm at the top and 10 cm at the bottom.
When the temperature of the T-4466 catalyst charged in the reaction tube is raised to 150 ° C. and maintained at the same temperature, and 30 ml / min of hydrogen and 30 ml / min of nitrogen are supplied from the top of the reaction tube, the catalyst generates heat, and the temperature of the catalyst Rose to 220 ° C. Hydrogen and nitrogen were continuously supplied until the catalyst no longer generated heat, and then the temperature of the catalyst was raised to 200 ° C. to maintain the same temperature. After confirming that there was no heat generation of the catalyst at 200 ° C., the supply of hydrogen was stopped.
1-2. Reaction Step The temperature of the T-4466 catalyst reduced in 1-1 of Example 1 was maintained at 300 ° C., and ethylene glycol: formaldehyde: ammonia: methylamine = 1: 1.5: 4: 1 from the top of the reaction tube. .5 (molar ratio) mixture was fed with 30 ml / min nitrogen at LHSV = 0.1 (g / cc-catalyst · h) based on ethylene glycol. The reaction gas discharged from the lower part of the reaction tube was bubbled into 100 ml of water to obtain a solution containing the reaction product. As a result of analyzing the solution containing the reaction product after 1.5 hours from the start of the reaction by gas chromatography, the conversion of ethylene glycol was 100% and the yield of 1-methylimidazole was 45%. .

Example 2
2-1. Catalyst reduction treatment step The same method as 1-1 in Example 1 except that the catalyst was replaced with N204 catalyst (Cu: 29 wt%, Cr: 31 wt%, Mn: 3 wt%) manufactured by JGC Catalysts & Chemicals, Inc. The catalyst reduction treatment was carried out.
2-2. Reaction step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the N204 catalyst reduced in Example 2-1. As a result, the conversion of ethylene glycol was 99%, and the yield of 1-methylimidazole was 45%.

Example 3
3-1. Catalyst preparation step 55.0 g of N204 catalyst (Cu: 29 wt%, Cr: 31 wt%, Mn: 3 wt%) manufactured by JGC Catalysts & Chemicals Co., Ltd. in a solution of 4.56 g of silver nitrate dissolved in 8.5 g of ion-exchanged water. The N204 catalyst was impregnated with an aqueous silver nitrate solution by dipping. The N204 catalyst impregnated with the aqueous silver nitrate solution was dried at 130 ° C. and then calcined at 550 ° C. for 5 hours to prepare a 5 wt% Ag / N204 catalyst.
3-2. Catalyst reduction treatment step The catalyst reduction treatment was carried out in the same manner as in Example 1-1, except that the catalyst was replaced with the 5 wt% Ag / N204 catalyst prepared in Example 3-1.
3-3. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the 5 wt% Ag / N204 catalyst reduced in 3-2 of Example 3. As a result, the conversion of ethylene glycol was 85%, and the yield of 1-methylimidazole was 48%.

Example 4
4-1. Catalyst preparation step A 5 wt% Ag / N204 catalyst was prepared in the same manner as in Example 3-1, except that the calcination temperature of the catalyst was 400 ° C.
4-2. Catalyst reduction treatment step The catalyst reduction treatment was carried out in the same manner as in Example 1-1, except that the catalyst was replaced with the 5 wt% Ag / N204 catalyst prepared in Example 4-1.
4-3. Reaction step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the 5 wt% Ag / N204 catalyst reduced in 4-2 of Example 4. As a result, the conversion of ethylene glycol was 97%, and the yield of 1-methylimidazole was 50%.

Example 5
5-1. Catalyst preparation step 55.0 g of N204 catalyst (Cu: 29 wt%, Cr: 31 wt%, Mn: 3 wt%) manufactured by JGC Catalysts & Chemicals Co., Ltd. in a solution of 7.02 g of silver nitrate dissolved in 8.5 g of ion-exchanged water. The N204 catalyst was impregnated with an aqueous silver nitrate solution by dipping. The N204 catalyst impregnated with the aqueous silver nitrate solution was dried at 130 ° C. and then calcined at 400 ° C. for 5 hours to prepare a 7.5 wt% Ag / N204 catalyst.
5-2. Catalyst reduction treatment step The catalyst reduction treatment was carried out in the same manner as in Example 1-1, except that the catalyst was replaced with the 7.5 wt% Ag / N204 catalyst prepared in Example 5-1.
5-3. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the 7.5 wt% Ag / N204 catalyst reduced in 5-2 of Example 5. As a result, the conversion of ethylene glycol was 98%, and the yield of 1-methylimidazole was 53%.

Example 6
6-1. Catalyst reduction treatment step Nylon catalyst (Cu: 36 wt%, Cr: 30 wt%, Mn: 3 wt%, 60 MPa) manufactured by JGC Catalysts & Chemicals Co., Ltd. in a reaction tube made of Pyrex (registered trademark) with an inner diameter of 19 mm, The pressed solid material was crushed and then classified into 10 to 16 meshes), and filled with 15 ml of carborundum with a length of 22 cm at the top of the packed bed of catalyst and 10 cm at the bottom.
When the N203 catalyst charged in the reaction tube is heated to 300 ° C. and kept at the same temperature, and 30 ml / min of hydrogen and 30 ml / min of nitrogen are supplied from the upper part of the reaction tube, the catalyst generates heat and the temperature of the catalyst becomes 350 ° C. It rose to ℃. After supplying hydrogen and nitrogen until the catalyst no longer generates heat, the supply of hydrogen was stopped when the catalyst no longer generated heat.
6-2. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst was replaced with the N203 catalyst reduced in Example 6-1. As a result, the conversion of ethylene glycol was 100%, and the yield of 1-methylimidazole was 49%.

Example 7
7-1. Catalyst Preparation Step 40.4 g of N203 catalyst (Cu: 36 wt%, Cr: 30 wt%, Mn: 3 wt%) manufactured by JGC Catalysts & Chemicals Co., Ltd. in a solution prepared by dissolving 3.27 g of silver nitrate in 36.2 g of ion-exchanged water. The N203 catalyst was impregnated with an aqueous silver nitrate solution by dipping. The N203 catalyst impregnated with the aqueous silver nitrate solution was dried at 130 ° C., calcined at 550 ° C. for 5 hours, and the resulting solid was pressed at 60 MPa. The pressed solid was pulverized and classified to 10 to 16 mesh to prepare a 5 wt% Ag / N203 catalyst.
7-2. Catalyst reduction treatment step The catalyst reduction treatment was carried out in the same manner as in Example 6-1 except that the catalyst was replaced with the 5 wt% Ag / N203 catalyst prepared in Example 7-1.
7-3. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst was replaced with the 5 wt% Ag / N203 catalyst reduced in 7-2 of Example 7. As a result, the conversion of ethylene glycol was 100%, and the yield of 1-methylimidazole was 52%.

Example 8
8-1. Catalyst reduction treatment step Example 1 of Example 1 except that the catalyst was replaced with a G-99CK catalyst (Cu: 37 wt%, Cr: 31 wt%, Mn: 2 wt%, Ba: 2 wt%) manufactured by Clariant Catalyst Co., Ltd. Catalyst reduction treatment was performed in the same manner as in 1-1.
8-2. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the G-99CK catalyst reduced in Example 8-1. As a result, the conversion of ethylene glycol was 99%, and the yield of 1-methylimidazole was 40%.

Example 9
9-1. Catalyst reduction treatment step 1-1 of Example 1 except that the catalyst was changed to G-22 / 2 catalyst (Cu: 38 wt%, Cr: 24 wt%, Ba: 5 wt%) manufactured by Clariant Catalyst Co., Ltd. A catalytic reduction treatment was performed in the same manner.
9-2. Reaction step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the G-22 / 2 catalyst reduced in Example 9-1. As a result, the conversion of ethylene glycol was 99%, and the yield of 1-methylimidazole was 37%.

Example 10
The catalyst reduction treatment and reaction were carried out in the same manner as in Examples 2-1 and 2-2 of Example 2, except that the temperature in the reaction step was 250 ° C. As a result, the conversion of ethylene glycol was 74%, and the yield of 1-methylimidazole was 30%.

Example 11
Catalyst reduction treatment and reaction were carried out in the same manner as in Examples 2-1 and 2-2 except that the temperature of the reaction step was 275 ° C. As a result, the conversion of ethylene glycol was 93%, and the yield of 1-methylimidazole was 43%.

Reference example 1
1-1. Catalyst reduction treatment step The catalyst reduction treatment was carried out in the same manner as in Example 6-1 except that the catalyst was replaced with N2C catalyst (Cu: 39 wt%, Zn: 36 wt%) manufactured by JGC Catalysts & Chemicals Co., Ltd. did.
1-2. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the N211 catalyst reduced in 1-1 of Reference Example 1. As a result, the conversion of ethylene glycol was 31%, and the yield of 1-methylimidazole was 1%.

Reference example 2
2-1. Catalyst reduction treatment step The same as Example 1-1 of Example 1 except that the catalyst was replaced with T-8706 catalyst (Cu: 43 wt%, Mn: 7 wt%, Al: 6 wt%) manufactured by Clariant Catalyst The catalyst reduction treatment was carried out by the method.
2-2. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the T-8706 catalyst reduced in 2-1 of Reference Example 2. As a result, the conversion of ethylene glycol was 89%, and the yield of 1-methylimidazole was 6%.

Reference example 3
3-1. Catalyst reduction treatment step The same method as in Example 1-1, except that the catalyst was replaced with a Cu-0865T catalyst (Cu: 47 wt%, Ca: 11 wt%, Si: 8 wt%) manufactured by BASF Corporation The catalyst reduction treatment was carried out.
3-2. Reaction Step The reaction was carried out in the same manner as in Example 1-2, except that the catalyst used in the reaction was replaced with the Cu-0865T catalyst reduced in 3-1 of Reference Example 3. As a result, the conversion of ethylene glycol was 72%, and the yield of 1-methylimidazole was 9%.

Claims (8)

A method for producing a 1-alkylimidazole compound, comprising subjecting a vicinal diol compound, formaldehyde, ammonia and a primary amine compound or primary alcohol compound to a gas phase catalytic reaction in the presence of a catalyst containing copper and chromium. A catalyst containing copper and chromium, a catalyst containing copper, chromium and a metal belonging to group 7 of the periodic table, a catalyst containing copper, chromium and a metal belonging to group 11 of the periodic table (excluding copper), 2. The method according to claim 1, which is at least one selected from the group consisting of a catalyst containing copper, chromium, a metal belonging to Group 7 of the periodic table, and a metal belonging to Group 11 of the periodic table (excluding copper). -Method for producing alkylimidazole compound. Catalyst containing copper and chromium contains copper, chromium and manganese containing catalyst, copper, chromium and barium containing catalyst, copper, chromium, manganese and barium containing catalyst, copper, chromium, manganese and silver The method for producing a 1-alkylimidazole compound according to claim 1, wherein the method is at least one member selected from the group consisting of: 2. The method for producing a 1-alkylimidazole compound according to claim 1, wherein the catalyst containing copper and chromium is a catalyst containing copper and chromium which has been subjected to reduction treatment before use. The method for producing a 1-alkylimidazole compound according to claim 1, wherein the catalyst containing copper and chromium is a catalyst containing copper and chromium which has been subjected to hydrogen reduction treatment before use. The process for producing a 1-alkylimidazole compound according to claim 1, wherein the catalyst containing copper and chromium is a catalyst containing copper and chromium which has been subjected to hydrogen reduction treatment at 125 to 375 ° C before use. The method for producing a 1-alkylimidazole compound according to any one of claims 1 to 6, wherein a gas phase catalytic reaction is carried out at 250 to 325 ° C. 1. A reaction gas obtained by gas phase catalytic reaction of a vicinal diol compound, formaldehyde, ammonia and a primary amine compound or primary alcohol compound in the presence of a catalyst containing copper and chromium is absorbed in water. -Method for producing alkylimidazole compound.