Synthesis of some new 2,4,6-trisubstituted phenyl pyrimidines using 4-nitro and 4-fluorophenacyldimethylsulfonium bromides with aromatic aldehydes

Abstract

4-Nitrophenacyldimethylsulfonium bromide and 4-fluorophenacyldimethylsulfonium bromide have been prepared by the reaction of dimethyl sulfide with 4-substitutedphenacyl bromide in benzene at reflux temperature under nitrogen atmosphere. These sulfonium salts on treatment with NaOH gave 4-nitrophenacylidenedimethylsulfurane and 4-fluorophenacylidenedimethylsulfurane. The reaction of these sulfonium salts and sulfuranes with various aromatic aldehydes is carried out in presence of ammonium acetate and acetic acid at reflux in an atmosphere of nitrogen to give 2,4,6-triarylpyrimidines in 35-80% yields. Ammonium acetate in acetic acid was used as aza cyclization agent. The structures of new pyrimidines were confirmed on the basis of IR and NMR spectral data.