Synthesis and cytotoxic activity on islets of Langerhans of benzamide thiosemicarbazone derivatives
摘要:
Eleven 1-(4-substituted alpha-arylaminobenzylidene)thiosemicarbazides 1 and the related semicarbazones 2 were synthesized and tested in vitro for their inhibitory effects on the islets of Langerhans. Only the thiosemicarbazones 1 suppressed the insulin and glucagon secretions while the somatostatin release persisted. The 1-(alpha-anilino-4-methylbenzylidene)thiosemicarbazide 1f was the most potent suppressor of insulin release and lysed the islet beta cells. Zinc sulfate protected islets from the suppressive and toxic effects of 1f. These compounds 1 could be potential drugs for the treatment of insulinomas.
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 Se-aryl carboselenothioates 3 (RCSSeAr, R=alkyl, aryl) were synthesized and characterized from the reaction of bis(thioacyl) sulfides 1 with sodium areneselenolates. The thionselenolesters 3 are stable (liquid or crystals) both thermally and to moisture. Reactions of 3 with aliphatic primary and secondary amines gave the corresponding ammonium carbodithioates 8 together with diphenyl diselenide