Fluorine-containing heterocycles: synthesis and some reactions of new 3-amino-2-functionalized-6-(2 '-thienyl)-4-trifluoromethylthieno [2,3-b]pyridines

3-Cyano-6-(2'-thienyl)-4-trifluoromethylpyridine-2 (1H)-thione (2) was prep ared and reacted with chloroacetone or phenacyl bromide to yield the 2-acet yl or benzoyl-3-amino-6-(2'-thienyl)-4-trifluoromethylthieno [2,3-b]pyridin es (3a, b). In contrast, the reaction of 2 with chloroacetamide or its N-ar yl derivatives gave the corresponding 2-carbamoylmethyl thiopyridines 4a-c. Upon treatment of these educts with K2CO3 or C2H5ONa in ethanol, they unde rwent intramolecular Thorpe-Ziegler cyclization to afford 3-amino-2-carbamo yl-6-(2'-thienyl)-4-trifluoromethyl-thieno[2,3-b]pyridine (5a) and its N-ar yl analogs 5b, c. Compounds 5a-c underwent some reactions to yield new pyri do[3',2':4,5]thieno[3,2-d]pyrimidines and pyrido[3',2': 4,5]thieno[3,2-d][1 ,2,3] triazines.