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

Dnepartment of Applied Chemistry, Birla Institute of Engineering and Technology, Jhansi-284 001, Uttar Pradesh, India Department of Chemistry, D. V. (P.G.) College, Orai-285 001, Uttar Pradesh, India Manuscript received 6 February 2006, revised 14 November 2006, accepted 2 February 2007 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- itrophenacylidenedimethylsulfuranc 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