Recent developments in aminopyrazole chemistry

Abstract

Recently reported syntheses of 3(5)-aminopyrazoles, 4-aminopyrazoles, and 1-aminopyrazoles as well as of diaminopyrazoles and their general pattern of reactivity towards mono- and bidentate electrophiles have been surveyed. Emphasis has also been laid on techniques for ascertaining the site selectivity in reactions with electrophiles, including single crystal X-ray structure analysis, 1H-15N HMBC, and NOE intensity difference experiments as well as other modern 2D NMR techniques. Some thermally induced cycloadditions have also been treated.