Studies on the synthesis of heterocyclic compounds. Part X. One-step route to 1,2-dimethyl-3-R-5-salicyloylimino-3-pyrazolines

This communication outlines the development of a direct synthetic route to 1,2-dimethyl-3-R-5-salicyloyl-imino-3-pyrazolines, starting from readily available 3(5)-aminopyrazoles 1a, b, c and methyl salicylate. The structures of the new compounds 3a, b, c were determined on the basis of analytical and spectroscopic data as well as on the acid hydrolysis products.