Synthesis of 3(5)-Amino-4-acylamino-5(3)-arylsulfanylpyrazoles and Their Fused Derivatives on the Basis of N-(2,2,2-Trichloro-1-hydroxyethyl)benzamides

Abstract

Addition products of carboxylic acid amides and trichloroacetaldehyde are readily converted into 3-arylsulfanyl-2-acylamino-3-chloroacrylonitriles which react with hydrazine hydrate to afford 3(5)-amino-5(3)-arylsulfanyl-4-acylaminopyrazoles. The presence of an amidine fragment in the latter makes them capable of undergoing cyclocondensations with b-dicarbonyl compounds and ethyl cyanoacetate.

Approaches towards the synthesis of 5-aminopyrazoles

“…Compounds 106 were readily obtained from 105 , the addition products of carboxylic acid amides and trichloroacetaldehyde, by the reaction sequence shown in the Scheme 30 [72]. …”