Regiospecific bromination of (2е, 4е) -5-aryl-2- (4-arylthiazol-2-yl) penta-2,4-dienenitriles

In the reaction of (2E, 4E) -5-phenyl-2-cyano-2,4-pentadientioamide or (E) -3- (2-nitrophenyl) acrolein and cyanothioacetamide with α-bromoketones received new (2E, 4E) -5-aryl-2- (4-arylthiazol-2-yl) penta-2,4-dienenitriles. Direct bromination of the latter by the action of Br2 in DMF proceeds regiospecifically at the C5 position of the thiazole ring without affecting the diene system and leads to the formation of previously undescribed (2E, 4E) -5-aryl-2- (5-bromo-4-arylthiazol-2-yl) penta-2,4-diennitriles. The structure of the reaction products was established using 2D NMR spectroscopy and X-ray diffraction analysis.