reaction of 4-arylidene-3H-pyrazol-3-one 1 with secondary and tertiary carbanionsderivedfrom a methylene and methine group bearing both a leaving group and electron-withdrawing group, e.g. methyl chloroacetate, ethyl chloroacetate, isopropyl chloroacetate, tert-butyl chloroacetate, chloroacetonitrile, 2-chloro-N,N-diethylacetamide, methyl 2-chloropropionate and 2-chloropropionitrile, in the presence of