Syntheses of hydrazides by a direct condensation reaction using phosphorous acid-iodine as a reagent

Aliphatic and aromatic hydrazides have been prepared in high to moderate yi elds by a direct condensation reaction of aliphatic or aromatic carboxylic acids with hydrazine or phenylhydrazine using phosphorous acid-iodine as re agent and pyridine as base and solvent. With aliphatic carboxylic acids, we obtained good results by heating at 80-90 degrees, for 5-6 hours, but with aromatic carboxylic acids are necessary 140-150 degrees, for the same peri od of time.