The preparation of several ethyl 3-(1,2-dialkylhydrazino)propanoates (III) by the reaction of 1,2-dialkylhydrazines with acrylates is described. Compound III is accompanied by small amounts of the bis addition products (V) in the reactions of ethyl acrylate with a few of the hydrazines. Cyclization of III to 1,2-dialkyl-3-pyrazolidinones (IV) was achieved with sodium methoxide. 1,2-Dialkyl-5-methyl-3-pyrazolidinones were obtained directly from 1,2-dialkylhydrazines and ethyl crotonate. A procedure for the preparation of 1,2-di-(2-ethoxycarbonylethyl)hydrazines is also given.