KR102500243B1 - Synthetic method of 5-(C1~C4 alkyl) tetrazole - Google Patents

Abstract

The present invention relates to a method for preparing a method for synthesizing 5-(C1-C4 alkyl) tetrazole, characterized in that a C1-C4 alkyl nitrile and an azide compound are reacted under at least one catalyst selected from zinc acetate and zinc sulfate. it's about According to the above method, the yield can be improved and the manufacturing cost can be reduced.

Description

Synthetic method of 5-(C1~C4 alkyl) tetrazole}

The present invention relates to a method for synthesizing 5-(C1-C4 alkyl) tetrazole.

5-(C1-C4 alkyl) tetrazole is widely used as a corrosion inhibitor in the manufacturing process of semiconductor devices and display devices.

Conventionally known methods for synthesizing 5-(C1-C4 alkyl) tetrazole, such as 5-methyl-1H-tetrazole, include methods according to Synthesis Example I and Synthesis Example II below.

[ synthesis example I]

[ synthesis example II]

Further, in the case of using a Lewis acid catalyst, a synthesis method by an aqueous phase reaction using ZnCl ₂ or a synthesis method by an aqueous phase reaction using Co(OAc) ₂ may be mentioned.

However, these methods have a disadvantage in that the production yield is low.

CN103351353A

The present invention has been made to solve the problems of the prior art,

It is an object of the present invention to provide a method for synthesizing 5-(C1-C4 alkyl) tetrazole with excellent yield and reduced manufacturing cost.

the present invention

Provided is a method for synthesizing 5-(C1-C4 alkyl) tetrazole, characterized by reacting a C1-C4 alkyl nitrile and an azide compound in the presence of at least one catalyst selected from zinc acetate and zinc sulfate.

According to the method for synthesizing 5-(C1-C4 alkyl) tetrazole of the present invention, the yield is excellent, and thus the production cost of alkyl tetrazole can be reduced.

the present invention

It relates to a method for synthesizing 5-(C1-C4 alkyl) tetrazole, characterized by reacting a C1-C4 alkyl nitrile with an azide compound in the presence of at least one catalyst selected from zinc acetate and zinc sulfate.

The above synthetic method is described by way of a reaction scheme as follows:

[Scheme I]

In the above formula,

R is a C1-C4 straight or branched chain alkyl group,

M is Na or K;

X is OAc or SO4;

n is 1 or 2;

Examples of the C1-C4 straight-chain or branched-chain alkyl group include straight-chain or branched-chain methyl, ethyl, propyl, butyl, and the like.

In the case of synthesizing 5-(C1-C4 alkyl) tetrazole by the above method, the yield may be increased by about 25% compared to the prior art.

In particular, zinc acetate may be preferably used as the at least one catalyst selected from zinc acetate and zinc sulfate.

In the synthesis method of the present invention, at least one selected from the group consisting of sodium azide and potassium azide may be used as the azide compound, more preferably sodium azide.

The C1-C4 alkyl nitrile may be used in an amount of 200 mol% to 1,000 mol% compared to the azide compound, and one or more catalysts selected from zinc acetate and zinc sulfate may be used in an amount of 100 mol% to 200 mol% compared to the azide compound.

The synthesis method of the present invention can be carried out in an organic solvent, and examples of the organic solvent include MeCN, DMF, NMP, DMSO, i -PrOH, n -BuOH, etc., which are used alone or in combination of two or more. can be used as The organic solvent can be simply removed by evaporation.

The synthesis method of the present invention can proceed with the reaction even in an aqueous solution, but in the case of using an aqueous solution, it takes a lot of time and money to remove water by distillation to obtain 5-(C1~C4 alkyl) tetrazole after the reaction is completed. It takes time, and even when obtained by precipitating 5-(C1-C4 alkyl) tetrazole, it has the disadvantage that it is difficult to produce a precipitate.

Zn contained in at least one catalyst selected from zinc acetate and zinc sulfate used in the synthesis method of the present invention is synthesized in the form of Zn(OH) ₂ by adding NaOH aqueous solution after synthesis of 5-(C1~C4 alkyl) tetrazole. It can be removed by precipitating.

Specifically, when an aqueous solution of NaOH is added and stirred at room temperature for 10 to 60 minutes, preferably for 20 to 40 minutes, more preferably for 30 minutes, Zn(OH) ₂ (white solid) is produced, so it can be removed by performing a filtration process. there is.

After removing the Zn(OH) ₂ , extraction is performed with an organic solvent such as ethyl acetate, and the obtained organic fraction is concentrated under reduced pressure to obtain 5-(C1-C4 alkyl) tetrazole.

In addition, the synthesis method of the present invention may further increase the purity of 5-(C1-C4 alkyl) tetrazole by further performing a recrystallization process. The recrystallization may be performed by a method such as a recrystallization method according to temperature or a recrystallization method by substitution with a poorly soluble solvent.

Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples. However, the following Examples and Comparative Examples are intended to illustrate the present invention, and the present invention is not limited by the following Examples and can be variously modified and changed.

Example 1:5 - methyl -1H- tetrazole synthesis

Acetonitrile (19.04 g, 4.0 equiv), n-BuOH (250 mL), NaN3 (7.54 g, 1.0 equiv), and zinc acetate (1.0 equiv) were added to a 500 mL round bottom flask at room temperature. The temperature was raised to 110° C. and stirred for 16 hours. After cooling to room temperature, n-BuOH was removed under reduced pressure. After adding 5% NaOH aqueous solution (180 mL, 2.0 equiv) and stirring at room temperature for 30 minutes, the resulting solid (zinc hydoxide) was removed by filtration. The reaction solution was extracted with ethyl acetate three times, and the obtained ethyl acetate layer was concentrated under reduced pressure to obtain the target 5-methyl-1H-tetrazole (white solid 10.59 g, 92%).

Example 2:5 - methyl -1H- tetrazole synthesis

Acetonitrile (19.04 g, 4.0 equiv), n-BuOH (250 mL), NaN3 (7.54 g, 1.0 equiv), and zinc sulfate (1.0 equiv) were added to a 500 mL round bottom flask at room temperature. The temperature was raised to 110° C. and stirred for 16 hours. After cooling to room temperature, n-BuOH was removed under reduced pressure. After adding 5% NaOH aqueous solution (180 mL, 2.0 equiv) and stirring at room temperature for 30 minutes, the resulting solid (zinc hydoxide) was removed by filtration. The reaction mixture was extracted with ethyl acetate three times, and the obtained ethyl acetate layer was concentrated under reduced pressure to obtain the desired 5-methyl-1H-tetrazole (white solid 10.82 g, 94%).

comparative example 1:5 - methyl -1H- tetrazole synthesis

Acetonitrile (1.0 equiv), NaN3 (1.43 g, 1.1 equiv), zinc bromide (4.5 g, 1.0 equiv), H ₂ O (40 mL), i-PrOH (4 mL) were added to a 250 mL round bottom flask at room temperature. was added. A reflux reaction was performed at 170° C. for 24 hours. After cooling to room temperature, 1 N NaOH aqueous solution (2.5 equiv) was added and stirred for 30 minutes. The resulting solid (zinc hydoxide) was removed by filtration. The reaction solution was extracted with ethyl acetate three times, and the obtained ethyl acetate layer was concentrated under reduced pressure to synthesize 1.37 g (75%) of 5-methyl-1H-tetrazole.

Claims (6)

A method for synthesizing 5-(C1-C4 alkyl) tetrazole, characterized by reacting a C1-C4 alkyl nitrile and an azide compound under at least one catalyst selected from zinc acetate and zinc sulfate. The method of claim 1,
The azide compound is a method for synthesizing 5- (C1 ~ C4 alkyl) tetrazole, characterized in that at least one selected from the group consisting of sodium azide and potassium azide. The method of claim 1,
The method for synthesizing 5- (C1-C4 alkyl) tetrazole, characterized in that the C1 ~ C4 alkyl carboxylic acid catalyst is zinc acetate. The method of claim 1,
The reaction is a method for synthesizing 5- (C1 ~ C4 alkyl) tetrazole, characterized in that carried out in an organic solvent. The method of claim 1,
Zn contained in the at least one catalyst selected from zinc acetate and zinc sulfate is removed by precipitating in the form of Zn(OH) ₂ by adding NaOH aqueous solution after synthesis of 5-(C1~C4 alkyl) tetrazole. Method for synthesizing 5- (C1-C4 alkyl) tetrazole. The method of claim 1,
The C1 to C4 alkyl nitrile is used in an amount of 200 mol% to 1,000 mol% compared to the azide compound, and at least one selected from zinc acetate and zinc sulfate is used in an amount of 100 mol% to 200 mol% 5-(C1 ~C4 alkyl) synthesis method of tetrazole.