A simplified Cadogan’s approach to synthesis of new isoxazolyl indazoles

Isoxazolyl Schiff bases have been prepared from the corresponding amines by reaction with 2-nitrobenzaldehydes.These nitro compounds undergo de-oxygenative cyclization to give indazoles via nitrenes on heating with triethyl phosphite in acetonitrile. Isoxazolyl indazoles have also been synthesized in a one-pot reaction.