Abstract

Synthesis and Evaluation of the Antioxidant Activity of Some 5- [7-Aryl-6-phenyl-5-thioxo 6,7-dihydro - 5H-[1,3,4] oxadiazolo [3,2, -a] [1,3,5] triazin-2-yl)-6-methyl-4-phneyl-3,4-dihydropyrimidin-2(1H) - one Derivatives

Author(s): Sonia George, R. Sabitha, P. Manoj Kumar and T. K. Ravi

Urea, benzaldehyde and ethyl acetoacetate were condensed by Biginelli reaction to form ethyl 6- methyl -2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate (1), which was further made to react with semicarbazide hydrochloride to form 2-[(6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidin-5-yl) carbonyl] hydrazine carboxamide (2). This product on reaction with concentrated sulphuric acid and further neutralization with ammonia gave 5-(5-amino-1,3,4-oxadiazol-2-yl)-6-methyl-4-phenyl-3,4- dihydropyrimidin-2(1H)-one (3). The resultant amino oxadiazolyl pyrimidinone is condensed with different aromatic aldehydes to obtain corresponding Schiff bases 4(a-j). These products on reaction with monochloroacetyl chloride and triethylamine gave 5-[5-(3-chloro-2-oxo-4-arylazetidin-1-yl)-1,3,4- oxadiazol-2-yl]-2(1H)-one 5(a-j). All these final compounds were characterized on the basis of spectral data and screened for their antioxidant activity.