Highly Regioselective Synthesis of 1-Aryl-3 (or 5)-alkyl/aryl-5 (or 3)-(<i>N</i>-cycloamino)pyrazoles

Abstract

[Reaction: see text]. An efficient highly regioselective protocol for the synthesis of isomeric 1,3-diaryl (or 1-aryl-3-alkyl) and 1,5-diaryl (or 1-aryl-5-alkyl)-5 (or 3)-(N-cycloamino)pyrazoles has been reported by cyclocondensation of common alpha-oxoketene N,S-acetal precursors with arylhydrazines by variation of reaction conditions.