JPH04308582A - Production of 4-amino-1,2,4-triazole - Google Patents

Abstract

PURPOSE:To produce the subject compound useful as a raw material for nitration-reducing agents, medicines, agricultural chemicals, UV ray absorbents, etc., in high yield and high purity by reacting formic acid. etc., with hydrazine in an organic solvent under heating. CONSTITUTION:Formic acid, an ester thereof (e.g. methyl ester, ethyl ester or an amide (e.g. formamide, dimethyl formamide) with hydrazine in an organic solvent (preferably a solvent having a boiling point of >=130 deg.C, e.g. xylene, mesitylene, chlorobenzene preferably at 130-170 deg.C for 2-20hr to provide the objective compound.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing 4-amino-1,2,4-triazole, which is useful as a nitrification inhibitor or as a raw material for medicines, agricultural chemicals, ultraviolet absorbers, and the like.

0002

BACKGROUND OF THE INVENTION Various methods have been known for producing 4-amino-1,2,4-triazole. For example, Japanese Patent Publication No. 46-35056 describes a method for producing 4-amino-1,2,4-triazole by reacting formic acid and hydrazine in the presence of phosphoric acid at 190°C or lower.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned manufacturing method, a small amount of phosphoric acid is mixed into the product, and this phosphoric acid is difficult to separate and remove, causing problems in terms of the quality of the target product, and also by-products. Bumping often occurs when water is distilled out of the reaction system, which poses operational problems. on the other hand,
It is undesirable to carry out the above reaction without the presence of phosphoric acid because the yield of the target product decreases.

0004

[Means for Solving the Problems] The present inventors conducted the reaction in the presence of an organic solvent without using phosphoric acid in the above-mentioned production method. It has been found that a high product can be obtained in a high yield, water as a by-product can be easily removed, and water can be smoothly distilled off without bumping during the distillation operation.

The present invention involves reacting formic acid, its esters or amides with hydrazine under heating to produce 4-amino-1
, 2,4-triazole, the method is characterized in that the reaction is carried out in the presence of an organic solvent.

[0006] In the present invention, formic acid, its esters or amides are reacted with hydrazine by heating in the presence of an organic solvent, but the order in which each raw material and organic solvent are added does not matter. and an organic solvent at once, or a mixture of hydrazine and an organic solvent is mixed with formic acid, its esters or amides.

[0007] Each raw material used in the present invention is exemplified below, and can be appropriately selected depending on the purpose of the reaction, reaction conditions, etc. Examples of esters and amides of formic acid other than formic acid include alkyl esters of formic acid such as methyl ester and ethyl ester of formic acid; amides of formic acid such as formamide and dithylformamide; preferably, formic acid and its amides; Among these, formic acid and dimethylformamide are more desirable. Further, as the hydrazine, hydrated hydrazine is preferable because anhydrous hydrazine emits strong smoke in the air and is difficult to handle.

Furthermore, the organic solvent used in the present invention may be any organic solvent as long as it is inert to the reaction.
It is preferable that it is insoluble or poorly soluble in water and the target substance 4-amino-1,2,4-triazole and has a boiling point of 130°C or higher.
For example, xylene, mesitylene, chlorobenzene, o, m
, p-dichlorobenzene, 1,2,4-, 1,3,5-
Examples include aromatic hydrocarbons such as trichlorobenzene, o, m, p-chlorotoluene, and aliphatic saturated hydrocarbons such as decane and undecane, but of course, mixtures thereof may be used.

In the present invention, the amounts of raw materials and organic solvents to be used vary depending on their types, reaction conditions, etc., and cannot be unconditionally defined, but the amount of hydrazine used is usually 0.0% per mole of formic acid, its esters, or amides. The amount is preferably 8 to 1.5 mol, preferably around 1 mol, and the organic solvent is usually 5 mol.
-500 parts by weight, preferably 30-100 parts by weight.

[0010] Although the reaction conditions for the reaction of the present invention cannot be defined unconditionally, the reaction temperature is preferably 130 to 190°C, preferably 130 to 170°C, and the reaction time is 2 to 20 hours. The reaction is usually carried out by refluxing the water produced as a by-product during the reaction until the hydrazine in the reaction mixture disappears, but the presence of a large amount of solvent prevents bumping and prevents decomposition of the target product and by-products due to local heating. The occurrence of reactions can also be prevented.

In addition, in the present invention, the target product, 4-amino-1,2,4-triazole, is generally present in the reaction product with almost no solubility in the solvent and water, so the target product can be easily obtained by liquid separation. If necessary, the target product may be recovered by distilling off the solvent. In this way, the target product, 4-amino-1,2,4-triazole, can be obtained, for example, in a yield of 91% or more and a purity of 91% or more.

[0012] Next, examples according to the present invention will be described, but the present invention is not limited to these descriptions.

Example 1 20 units equipped with a stirrer, a thermometer, a cooling tube and a dropping funnel
514 g (8.23 mol) of 80% hydrazine monohydrate and 600 g of xylene in a 00 ml four-necked flask.
g was prepared at room temperature. 87% formic acid 435g (8.2
When 3 mol) was added dropwise with stirring over 30 minutes using a dropping funnel, heat generation occurred and the temperature rose to 90°C. Thereafter, the mixture was heated and stirring was continued at 105° C. for 3 hours. During this time, the produced water was returned to the system through a cooling pipe. Then, the cooling pipe
Replace it with a moisture metering receiver equipped with a cooling pipe at the top (remove only the produced water from the system and return the solvent to the system) and heat it to 138°C. At that temperature, the concentration of hydrazine is 1% or less. The reaction was continued until The reaction time at 138℃ is 1
It was 5 hours.

After the reaction was completed, the mixture was cooled to 100° C. and the target product in the lower layer was separated by liquid separation. Since it contained some xylene, xylene was removed under reduced pressure. The target is 33
6 g (crude yield 97.2%) was obtained, and the purity was 93.1%.

Example 2 20 units equipped with a stirrer, thermometer, cooling tube and dropping funnel
62.5 g (1.0 mol) of 80% hydrazine monohydrate and ISOPAR-G in a 0 ml four-necked flask.
75g was charged at room temperature. 87% formic acid 52.9
When the mixture was added dropwise with stirring over 10 minutes using a dropping funnel, heat generation occurred and the temperature rose to 80°C. Thereafter, the mixture was heated and stirring was continued at 105° C. for 3 hours. During this time, the produced water was returned to the system through a cooling pipe. Then, the cooling tube was replaced with a water quantitative receiver equipped with a cooling tube at the top similar to that in Example 1, and after heating to 165°C, the reaction was continued at that temperature until the concentration of hydrazine became 1% or less. did. The reaction time at 165°C was 6 hours.

After the reaction was completed, the mixture was cooled to 100° C. and the target product in the lower layer was separated by liquid separation. Since some ISOPAR-G was contained, ISOPAR-G was removed under reduced pressure. 38.5g (crude yield 91.7%) of the target product was obtained,
Purity was 95.4%.

ISOPAR-G Aliphatic saturated hydrocarbon with average molecular weight 149, carbon number 10-11, specific gravity 0.75
0, flash point 41℃, aniline point 41℃, distillation range (initial boiling point 158℃, 5%-160℃, 10%-161℃, 50
%-164℃, 90%-170℃ and 95%-173℃
) Products of Exxon Chemical Co., Ltd.

Example 3 10 equipped with a stirrer, thermometer, cooling tube and dropping funnel
93.8 g (1.5 mol) of 80% hydrazine monohydrate, 131.6 g (1.8 mol) of dimethylformamide (DMF), and 130 g of xylene were charged into a 00 ml four-necked flask at room temperature, but no heat generation was observed. There wasn't. Stirring was started, and the reaction was carried out while heating and refluxing at 100° C. for 3 hours. Then, the cooling pipe was replaced with a moisture metering receiver equipped with a cooling pipe on the upper part as in Example 1.
After heating to ℃, the concentration of hydrazine becomes 1 at that temperature.
The reaction was continued until the concentration decreased to below %. The reaction time at 138°C was 18 hours.

After the reaction was completed, the mixture was cooled to 100° C. and the target product in the lower layer was separated by liquid separation. Since it contained some xylene, xylene was removed under reduced pressure. The target is 57
．． 7g (crude yield 91.6%) obtained, purity 91.0%
Met.

Example 4 10 equipped with a stirrer, thermometer, cooling tube and dropping funnel
93.8 g (1.5 mol) of 80% hydrazine monohydrate, 110 g (1.5 mol) of dimethylformamide (DMF), and 113 g of ISOPAR-G as in Example 1 were placed in a 00 ml four-necked flask at room temperature. However, no fever was observed. Stirring was started, and the reaction was carried out while heating and refluxing at 105° C. for 3 hours. Then, the cooling tube was replaced with a water quantitative receiver equipped with a cooling tube at the top similar to that in Example 1, and after heating to 160°C, the reaction was continued at that temperature until the concentration of hydrazine became 1% or less. . The reaction time at 160°C was 8 hours.

After the reaction was completed, the mixture was cooled to 100° C. and the target product in the lower layer was separated by liquid separation. Since some ISOPAR-G was contained, ISOPAR-G was removed under reduced pressure. 53.6g (crude yield 95.7%) of the target product was obtained,
Purity was 93.0%.

Claims (1)

[Claims] Claim 1: Formic acid, its esters or amides are reacted with hydrazine under heating to produce 4-amino-1,2
, 4-triazole, characterized in that the reaction is carried out in the presence of an organic solvent.
Method for producing 1,2,4-triazole.