A novel and efficient synthesis of 3-aminomethyl-N-tosyl-indazoles

A practical and environmentally friendly synthesis of 3-aminomethyl-N-tosyl-indazoles is developed. The in situ formed vinyl azines are reacted with amines to furnish amino functionalized anti-hydrazones in excellent yields. Subsequent copper-catalyzed cyclization at ambient temperature is effective and desired compounds are obtained in short reaction times. Also, the formation of bisindazoles is presented for the first time.