Study on Synthesis and Antibacterial Efficacy of Chloro-Substituted 1,3-Thiazines

Thiazines are very useful units in the fields of medicinal and pharmaceutical chemistry and have been reported to exhibit a variety of biological activities. This has directed us to synthesize chloro-substituted thiazines from 2'-hydroxy-3',5'-dichloro-4-4'-chlorophenyl chalcone with thiourea, phenyl thiourea and diphenyl thiourea. In this series, we have synthesized 4-(2'-hydroxy-3',5'-dichlorophenyl)-6- (4'-chlorophenyl)-2-imino-1,3-thiazine and 4-(2'-hydroxy-3',5'-dichlorophenyl)-6-(4'-chlorophenyl)-2-iminophenyl-1,3-thiazine from thiourea and phenyl thiourea respectively and 4-(2'-hydroxy-3',5'-dichlorophenyl)-6-(4'-chlorophenyl)-2-iminophenyl-3-phenyl-1,3- thiazine from diphenyl thiourea. The newly synthesized chloro-substituted 1,3-thiazines were screened for their antibacterial activities against Gram positive pathogens Staphylococcus aureus and Streptococcus sp. and Gram negative pathogens Pseudomonas sp. and Salmonella typhi. All these compounds have been characterized on the basis of their UV, IR and NMR spectral studies.