A simple one-pot synthesis of 1,2,3,4-tetrahydro-2-thioxopyrimidine derivatives

5-Benzoyl-4-(substituted phenyl)-6-phenyl-1,2,3,4-tetrahydro-2-thioxopyrimidines (4a-d) were synthesized using the Biginelli three component cyclocondensation reaction of an appropriate beta-diketone, arylaldehyde, and thiourea in acetic acid under reflux condition in approximately 52-65% yields. The acetylation of compounds 4a-d gave 3-acetyl thioxopyrimidine derivatives 5a-d. Also, pyrimidothiazine compounds 6a-d were prepared by a simple one-pot condensation reaction of starting pyrimidine derivatives 4a-d and 3-bromopropionic acid. The structures of compounds were characterized on the basis of elemental analyses, IR,H-1 and C-13-NMR spectra.