Synthesis of 2-(4-substitutedsulfonyl piperazin-1-yl-methyl)-3-aryl-quinazolin-4(3<i>H</i>)-one

923-928 Reaction of 2-(chloromethyl)-3-arylquinazolin-4(3H)-one 3 with N-BOC piperazine 4 in acetonitrile using K2CO3 and KI, followed by deprotection of BOC group in IPA HCl, gives 3-aryl-2-(piperazin-1-yl)quinazolin-4(3H)-one 6. The latter on treatment with benzene/methane sulfonyl chloride in DCM in the presence of TEA at RT, results in the formation of 2-(4-benzene/methane sulfonylpiperazin-1-yl-methyl)-3-aryl-quinazolin-4(3H)-one 7. Alternatively, 7 can also be prepared from the reaction of 4-benzene/methane sulfonyl-piperazine 9 with 3, in the presence of K2CO3 and KI.