Reactions of styrylthienyl ketone, styryl furyl ketone with thiocyanoacetamide:: Synthesis of several new pyridines, thieno[2,3-b]pyridines, pyrido [2′,3′:4,5]thieno[3,2-c]pyridazines and pyrido-[3′,2′:4,5]thieno[3,2-d]pyrimidin one derivatives

Styryl thienyl ketone and Styryl furyl ketone 2a,b reacted with thiocyanoacetamide(1) to give the dihydropyridinethiones 3a,b which used as starting material for the synthesis of several heterocyclic compounds. Reaction with several halogeno-esters, halogeno- ketones and chloroacetamide gave 2-S-alkoyl pyridines 5a-d, 10a-d, 13a,b and 19a,b thieno[2,3-c] pyridines 6a,b, 11a,b 14a,b and 20a-d, pyrido[2',3',4:5]thieno[2,3-c]pyridazines 8a,b and pyrido[2'.3':-4,5]thieno[2,3-d]pyrimidinones 15a, b 16a,b and 17a,b. Structures were established based on elemental analyses and spectral data studies.