SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SOME NEW PYRIDINE-2(1H)-THIONES, NICOTINAMIDES ,THIENO[2,3-B]-PYRIDINES, PYRIDO[3',2':4,5 ]- THIENO[3,2-D]PYRIMIDINES AND PYRIDO[3',2':4,5]THIENO[3,2-D][1,2,3]- TRIAZINES CONTAINING ANTIPYRINE MOIETY.

N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-3-oxobutanamide (1) reacts with arylidinecyanothioacetamides 2a–c in ethanol/piperidine solution under reflux to yield the pyridine-2(1H)-thiones 5a–c. Compound 5a reacts with α-haloketones 6a–e to give the nicotinamide derivatives 7a–e, which cyclized to thienopyridine derivatives 8a–e. The reaction of compound 8a with formamide, phenyl isothiocyanate and hydrazine hydrate afforded the pyridothienopyrimidine derivatives 9, 11 and thienopyridine carbohydrazide derivative 12 respectively. Also, the reaction of 12 with phenyl isothiocyanate under reflux gave the thienopyridine derivative 14. Condensation of 8b,c with DMF-DMA afforded the corresponding 3-[(dimethylamino)methylene)-amino]thienopyridine derivatives 15a,b, which cyclized into the pyridothienopyrimidine derivatives 16a,b. Self coupling of compounds 8b,c were occurred through their diazotization where, the corresponding pyridothienotriazine derivatives 17a,b were obtained. Most of the target compounds were then evaluated for their antimicrobial and antifungal activities.