Studies on Reactions of Pyrimidine Compounds. 2¹. Microwave-Assisted Synthesis of 1,2,3,4-Tetrahydro-2- Thioxopyrimidine Derivatives

The 5-benzoyl-4,6-diphenyl-1,2,3,4-tetrahydro-2-thioxopyrimidine ( 1a ) and 5-benzoyl-4-(2-chlorophenyl)-6-phenyl-1,2,3,4-tetrahydro-2-thioxopyrimidine ( 1b ) were synthesized using the Biginelli three-component cyclocondensation reaction of a β -diketone, arylaldehyde, and thiourea under microwave irradiation. Thiazolopyrimidine ( 2 ), ( 3 ) and pyrimido[2,3-b]thiazine ( 4 ) derivatives were obtained by a simple one-pot condensation reaction of starting compound 1b and 2-bromopropionic acid, bromoacetic acid and 3-bromopropionic acid, respectively. These reactions performed under microwave irradiation and conventional conditions. That study is suggested a simple and efficient route for the preparation of 1,2,3,4-tetrahydro-2-thioxopyrimidine and derivatives.