N-Alkenyl-3,5-Pyrazolidinediones from Ketone Hydrazones, PCl3 and Malonic acid.

Article abstract of DOI:10.1016/0040-4020(95)00550-R

The title compounds 3, a new series of 3,5-pyrazolidinediones, have been synthesized at room temperature by a one-pot reaction between ketone hydrazone 1, PCl3 and malonic acid.Changing the order of addition of reagents, or their simultaneous addition, gave identical results.In all the procedures the yields are good and in the cases a,b,c and g the E-alkenyl isomer was obtained as the exclusive isomer.A dual mechanism which depends on the order of addition of the reactants is hypothesised.