Synthesis of 1H-indazoles using lemon peel powder as a natural, green and efficient catalyst under ultrasound irradiation

Bioactive 1H-indazoles were synthesized from 2-substituted aromatic aldehydes and hydrazine hydrate using DMSO and lemon peel powder as a green and efficient natural catalyst. In comparison to other reported conventional methods, this method affords good yield under ultrasonic irradiation.