ABSTRACT A mixed bases mediated protocol is developed to synthesize thioamides from N-aryl or N-alkylamide, aldehyde and elemental sulfur in water. This reaction requires no addition of external oxidant and avoids large excess of amides. Various functional groups and pharmaceutically interesting heteroaromatic rings could be introduced via this efficient procedure. GRAPHICAL ABSTRACT
Three component reactions of olefins, amines, and sulfur were studied. Thioamidation of styrenes is base-controlled, and 2-phenylethanethioamides and benzothioamides were obtained selectively in the presence of two different bases. This protocol offers a simple and efficient procedure for the synthesis of thioamides.
A series of 2-(4-methylphenyl)benzothiazoles was synthesized and evaluated using an adjuvant-induced arthritic rat model. This calss of desired compounds affecting the immune response was found using hemagglutination assay.4-Acetoxy-2-(4-methylphenyl)benzothiazole (7m), KB-2683, was most potent in the adjuvant-induced arthritic rat model and selected for further evalution. In contrast to nonsteroidal antiinflammatory drugs, compound 7m showed no antiinflammatory or analgesic activities. It did, however, show an immunomodulatory activity in enhanced delayed type hypersensitivity.