Dynamit Nobel Aktiengesellschaft

Norbert Linkat

Gunter Bison

Wolfgang Wolfes

Klaus Thewalt

Walter Heinzelmann

It is suggested to produce 5-chloro-1H-tetrazolecarboxylic acid esters by reaction of dichloroisonitriloacetic acid esters with alkali or metal azides or ammonium azide. The dichloroisonitriloacetic acid esters required for this purpose are formed by reacting N-formylaminocarboxylic acid esters with chlorine or with compounds which split off chlorine.

Process for the preparation of dichloroisonitrilocarboxylic acid esters

A process for the preparation of 1H-tetrazole-1-acetic acid or its ester which comprises contacting trimethylsilyl azide with an orthocarboxylic acid ester of the formula

Process for the preparation of 1H-tetrazole-1 compounds using

Process for producing tetrazole-1-acetic acid of maximum purity includes the steps of providing a crude reaction product containing an alkyl ester of tetrazole-1-acetic acid having from 1 to 4 carbon atoms in the alkyl group, effecting molecular distillation of this reaction product at a temperature below 130.degree.C. under a vacuum of 10.sup.-.sup.1 torr to obtain a distillant containing the alkyl ester and then gently hydrolyzing the resultant distillate to obtain the desired acid product.

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St. Augustin, Germany

Norbert Linkat