DD207626A3 - PROCESS FOR PREPARING THE 3-AMINO-5-HYDRAZINO-1,2,4-TRIAZOL AND THE DERIVATIVES THEREOF - Google Patents

Abstract

The invention relates to a chemical synthesis. It is thus a novel process for the preparation of 3-amino-5-hydrazino-1,2,4-triazole described which by acid hydrolysis of the products from the reaction of 2-amino-5- (alkyl, aryl-1,3 , 4-oxadiazoles and acylating agents are obtained in the presence of catalytic amounts of strong acids in high purity and in high yields A derivatization of the reactive title compound is readily possible They, their salts or their derivatives can be used as herbicides, fungicides, drugs or as analytical reagent Find.

Description

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Process for the preparation of 3-amino-5-hydrazino-1,2,4-triazole and its derivatives

Field of application of the invention

Triazole compounds are used as herbicides and fungicides. Their use as drugs and as components in photochemistry is described. With the reactive substituents, the triazole compound is also suitable as a carbonyl reagent in the analysis.

Characteristic of the known technical solutions

The dihydrochloride of the title compound has hitherto been prepared by reduction of the 3,5-di- (nitrosamino) -1,2,4-triazole with tin chloride / Atolle, Dietrich: J. prakt. Chem. (2) 139 (1934) 193; Gray, Stevens: J. Chem. Soc. Perkin Trans. I (1976) 1492 /. In this reduction step, a metal salt is used, which is difficult to regenerate. The nitroso compound is obtained from 3,5-diamino-1,2,4-triazole with sodium nitrite or alkyl nitrite. It is thermally unstable and fumes when heated. The production of larger amounts of the title compound is problematic.

Object of the invention

With the production process according to the invention, the dihydrochloride of the title compound can also be produced in larger quantities without the disadvantages of the known synthesis route. No metal salts are needed. The by-products

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2i \ f η? "H ⁵ T

'are traceable again. They do not interfere with the derivatization of the title compound. The production of effective derivatives is thereby simplified.

Explanation of the essence of the invention. ,

The title compound is obtained as a salt in the acid hydrolysis of acylated 2-amino-5- (alkyl, aryl) -1,3,4-oxadiazoles. If their acylation is carried out in the presence of tertiary amines _r , the 2-acylamino-i, 3,4-oxadiazoles are formed, • which decompose into the corresponding fragments only by ring splitting / Gehlen, Just: Liebigs Ann. Chem. 703 (1967)

If, on the other hand, according to the invention, the acylation is catalyzed acidically, triacylated derivatives of the title compound are formed as intermediates which can easily be hydrolysed with strong acids to give the corresponding salts of the title compound.

The use of hydrochloric acid is most expedient because the dihydrochloride of 3-amino-5-hydrazino-1,2,4-triazole is sparingly soluble in concentrated hydrochloric acid. It can be isolated in almost theoretical yield, based on the 2-amino-1,3,4-oxadiazole used, and in high purity. , The substituent on the 2-amino-1,3,4-oxadiazole and the acylating agent used have no significant influence on the yield and the course of the reaction. Their selection can therefore only be determined by economic parameters (Table 1).

The acylation products do not need to be isolated. However, distilling off the excess acylating agent is expedient.

From the initially obtained dihydrochloride of 3-amino-5-. hydrazino-1,2,4-triazole can be released with a strong base ion exchanger, the base. It is much more volatile than the original salt. For subsequent reactions, the base isolation is not necessary.

Even for the preparation of dinitrate can from dihydric chloride

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be assumed. It easily reacts with carbonyl compounds. Here, the amino and the Hydraζinοgruppe react with aldehydes without significant gradations, while with ketones primarily only the corresponding hydrazones are formed.

For the preparation of carbonyl compounds, the isolation of the dihydrochloride from the hydrolysis is not required.

The dihydrochloride of the title compounds can be reacted by known methods with isocyanates, isothiocyanates, acyl isocyanates and acyl isothiocyanates and with acylating agents. The acylation products are not identical to the intermediates of the synthesis according to the invention.

embodiments

Example 1 (Table 1)

100 g of 2-amino-5-ethyl-1,3 »4-oxadiazole are stirred into the mixture of 120 g of ethanoic anhydride and 10 drops of perchloric acid (70 $) and heated in an oil bath at about 8C ⁰ C until homogenized. Then excess anhydride and liberated carboxylic acid is distilled off in vacuo. The residue is dissolved in 200 ml of concentrated hydrochloric acid with gentle heating. In a lively reaction forms rapidly after a crystal mash. After about 30 minutes, it is cooled to ⁰ ° C. Then it is sucked off and cooled with a little cold, concen-

washed hydrochloric acid washed. It is rinsed with ethanol and anhydrous diethyl ether. The dihydrochloride of 3-amino-5-hydrazino-1,2,4-triazole is dried in vacuo. From the concentrated filtrate can be after addition of concentrated hydrochloric acid and cooling another proportion

isolate the dihydrochloride.

Yield: 78 g ($ 94)

Example 2

To make the title link will be about $ 40

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Solution of the 3-Amin.o-5-hydrazino-1,2,4-triazole dihydrochloride in water passed through an exchange column with Wofatit SBW. It is rinsed with water until the run no longer reduces a sample of ammoniacal silver nitrate solution. The chloride-free, bluish-colored solution is concentrated in vacuo at 5O ⁰ C to dryness. The apparatus is flushed with pure nitrogen through the capillary. ,

The pale-colored residue is washed rapidly with a little anhydrous ethanol. The now almost colorless 3-amino-5-hydrazino-1,2,4-triazole is well sealed under Sticke fabric for a long time "resistant.

Yield: about $ 80

  Example 3

10 g of 2-amino-5-ethyl-1,3,4-oxadiazole are added to the mixture of 12 ml of ethanoic anhydride and 3 drops of perchloric acid (70 $ ig). Then it is heated in the 80 ⁰ C hot oil bath until homogenization. Subsequently, under vacuum, anhydride and. Distilled off carboxylic acid. The residue is mixed with 15 ml of concentrated hydrochloric acid. The temperature is kept at 80 ⁰ C for 10 minutes. After cooling, the solutions of 10 g of benzaldehyde in 25 ml of ethanol and 20 g of sodium acetate or sodium carbonate are stirred into 100 ml of water. After a short time, a precipitate forms, which is filtered off with suction and washed with water and then with a little ethanol. The dibenzylidene compound is dried in vacuo at about 150 ⁰ C. It can be recrystallised from ethanol. Mp .: 242 - 244 ⁰ C

Yield: 10.5 g (82% based on the

2-Amino-5-ethyl-1,3,4-oxadiazol)

8 5 7

Table 1

Dependence of the yield of 3-amino-5-hydrazino-1,2,4-triazole dihydrochleride of 2-amino-1,3,4-oxadiazole and of the Garbonsäureanhydrid

Amino-oxadiazole

5-methyl-5-methyl-5-ethyl-5-ethyl-

anhydride

yield

Acetic acid-propionic acid-acetic acid-propanoic

$ 35

$ 92

Claims (1)

235857 invention claim A process for the preparation of 3-amino-5-hydrazino-1,2,4-triazole and its derivatives, characterized in that 2-amino-1,3,4-oxadia2ole treated with acylating agents and catalytic amounts of strong acids and the resulting Acylierungsprodulcte with strong acids, notably
concentrated hydrochloric acid, be hydrolyzed.