Syntheses of Biologically active 1-[2-(1,3-Dimethyl-2,6-Dioxo-1,2,3,6Tetrahydro-Purin-7-Yl)-Acetyl]-3-(Substituted Phenyl)-1H-Pyrazole-4- Carbaldehyde

1-[2-(1,3-Dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-purin-7-yl)-acetyl]-3-(substituted phenyl)-1H-pyrazole-4-carbaldehydes (4a-e) have been synthesized by the cyclisation of (1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-purin-7yl)-acetic acid [1-(substituted phenyl)-ethylidene]-hydrazides (3a-e) with phosphorous oxychloride in N,Ndimethylformamide. The pyrazoles have been characterized on the basis of analytical and spectral data and screened for biological activity.