Synthesis, characterization of some 1-(2-hydroxy-phenyl)-3-(1-phenyl-3-thiophen-2-yl-1H-pyrazol-4-yl)-propenone, 3-chloro-2-(1-phenyl-3-thiophen-2-yl-1H-pyrazol-4-yl)-chromon-4-one and 2-(1′-phenyl-3′-thiophen-2-yl-3,4-dihydro-2H,1H′-[3,4]bipyrazol-5-yl)-phenol

Base catalyzed condensation of 1 with 2 gives compound 3 [1-(2-hydroxy-phenyl)-3-(1-phenyl-3-thiophen-2-yl- 1H-pyrazol-4-yl)-propenone]. 3 on oxidative cyclization with DMSO-CUCl2 gives 3-chloro-2-(1-phenyl-3-thiophen-2-yl- 1H-pyrazol-4-yl)-chromon-4-one 4. 3 on condensation with hydrazine hydrate gives 2-(1'-phenyl-3'-thiophen-2-yl-3,4-dihydro-2H, 1H'-[3,4]bipyrazol-5-yl)-phenol 5. The products 3, 4 and 5 were characterized by IR, H-1 NMR and mass spectroscopy.