Abstract

5-Phenylselenenyl-2,4-disubstituted pyrimidine analogs were prepared efficiently in four steps. Thiol group of 2-thiouracil was protected with various alkylating agents in presence of base furnishes 2-alkylthiouracils (2a-c), these on reaction with phenylselenenyl chloride in pyridine under anhydrous conditions yielded 5-phenylselenenyl-2-alkylthiouracils (3a-c). Chlorination of 5-phenyl-selenenyl-2-alkylthiouracils with excess POCl₃ under reflux furnishes 5-phenylselenenyl-4-chloro-2-alkylthiopyrimidines (4a-c). Aromatic nucleophilic substitution reaction of 5-phenyl-selenenyl-4-chloro-2-alkylthiopyrimidines with oxygen nucleophiles like sodium phenoxides furnished the target compounds (5a-o) in 60-75% yield. All the synthesized compounds were evaluated for antimicrobial activities.

Keywords

Pyrimidine analogs, 2-Alkyllthiouracils, 5-Phenylselenenylpyrimidines,
2,4,5-Trisubstituted pyrimidines