Method for the preparation of N,N-dialkyl hydrazides

A method for the preparation of an N,N-dialkyl acid hydrazide of the formula:

• ##STR3## wherein n is the integer 1 or 2;
• R is alkylene, m-phenylene or p-phenylene when n is 2;
• R is alkyl or aryl when n is 1;
• R' is lower alkyl;
• which comprises the steps:
• a. reacting hydazine with a lower alkyl ester of a carboxylic acid of the formula R--[COOH].sub.n wherein R and n have the above-defined meanings to form the corresponding unsubstituted acyl hydrazine;
• b. adjusting the pH of the reaction mixture of step (a) to not in excess of 7.5, and thereupon slowly and continuously adding at least 2 moles of a C.sub.1 -C.sub.6 aldehyde for each equivalent of acyl hydrazine formed in step (a) in the presence of hydrogen and a Group VIII metal catalyst while maintaining the reaction temperature at from about 40.degree. to 100.degree. C.;
• and
• c. recovering said dialkyl acid hydrazide from the reaction mixture of step (b).