Synthesis and antimicrobial evaluations of some novel fluorinated chromones and pyrazoles

383-3902-Hydroxy acetophenone on treatment with 4-chloro-2,5-difluorobenzoic acid in POCl3 as condensing agent gives ester. The ester on reaction with KOH undergoes Baker-Venkatraman rearrangement and gives ketoenols. The ketoenols on reaction with conc. HCl gives 2-substituted chromones which on further reaction with hydrazine hydrate gives 2-[5-(4-chloro-2,5-difluorophenyl)-1H-pyrazol-3-yl]phenol. The structures of all newly synthesized compounds have been confirmed on the basis of IR, 1H NMR and mass spectral techniques. Some of the synthesized compounds exhibit good antimicrobial activity against the tested strains