Diethyl (ethoxymethylene)malonate → [[(1-Ethyl-3-methyl-5-pyrazolyl)amino]methylene]malonic acid diethyl ester

Participants

Reaction Steps

12.5 g. of 1-ethyl-3-methyl-5-aminopyrazole (0.1 mol.) and 21.6 g. of ethoxymethylene malonic acid diethyl ester (0.1 mol.) are heated to 120° (bath temperature) for 2 hours with stirring. The ethanol formed by this reaction is removed by means of a water aspirator. Vacuum distillation (b.p. 0.05 152°-153°) yields 24.0 g. (81.5%) of a quickly crystallizing oil, [[(1-ethyl-3-methyl-5-pyrazolyl)amino]methylene]malonic acid diethyl ester, m.p. 60°-67°. The product, recrystallized from ligroin (90°-100° C), melts at 69°-70°.

Provenance & Evidence