Synthesis Of 2-(4,5-Dihydro-3,5-Diphenylisoxazole / Pyrazol-4ylthio)-6-Methylpyrimidin-4-One

Reaction of 2-mercapto-6-methylpyrimidin-4-one (1) with phenacyl bromide(2) in DMF in the presence of K2CO3 as a mild base for 3 hrs at RT followed by processing, gave 6-methyl-2-(3-oxo-3-phenylpropyl) pyrimidin-4-one (3). The latter on treatment with benzaldehyde (4) in ethanol under reflux yielded 2,1-oxo-1,3-diphenylprop-2-en-2-ylthio)-6methylpyrimidin-4-one (5). 5 on treatment with hydrazine hydride/hydroxyl amine hydrochloride in ethanol under reflux yielded 2-(4,5-dihydro-3,5-diphenylisoxazole /pyrazol-4ylthio)-6-methylpyrimidin-4-one (6)/(7)