A facile synthesis of 3,5-diaminopyrazole-4-carbothioamides and 3,5- diaminopyrazole-4-carboxylates

Cocco MT;CONGIU, CENZO;ONNIS, VALENTINA;Bernard AM;Piras PP

1999-01-01

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Abstract

Simple and convenient synthesis of hitherto unknown 3,5-diaminopyrazole- 4-carbothioamides 3 as well as new ethyl 3,5-diaminopyrazole-4-carboxylates 7 is reported. The key intermediates were 2-cyanopropenethioamides 2 and 2- (ethoxycarbonyl)propenethioamides 5 which were readily obtained by reaction of phenyl isothiocyanate with 3-(2-acylhydrazino)-3-aminopropenenitriles 1 and ethyl 3-(2-acylhydrazino)-3-aminopropenoates 4 respectively. Intramolecular cyclization of compounds 2 afforded pyrazole-4-carbothioamides 3 while propenethioamides 5 gave pyrazole-4-carboxylates 7.