A new procedure for preparation of carboxylic acid hydrazides.

The standard method for preparing carboxylic acid hydrazides is hydrazinolysis of esters in alcoholic solutions. However, when applied to alpha,beta-unsaturated esters, the main product typically is the pyrazolidinone resulting from an undesired Michael-type cyclization. Other alternative methodologies reported for direct preparation of hydrazides from acids are inefficient.