Synthesis and Reactions of Some New Heterocyclic Compounds Containing Cycloalka[e]thieno[2,3-b]pyridine Moiety

Abstract

Hydrolysis of ethyl 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxylates (3a-d) gave the corresponding o-aminocarboxylic acids 4a-d. Heating the latter compounds (4a-d) with acetic anhydride furnished the oxazinone derivatives 5a-d which, in turn, underwent recyclization reaction to give the corresponding pyrimidinones 6a-d upon treatment with ammonium acetate in acetic acid. Reaction of 3-amino-4-aryl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides (3f,h) with triethyl orthoformate gave pyrimidinone derivatives 7a,b. Reaction of 3-amino-4-phenyl-cycloalka[e]thieno[2,3-b]pyridine-2-carboxamides 3e,h with aromatic aldehydes furnished tetrahydropyridothienopyrimidinones 8a-d. Chlorination of 7a,b and 6a-d by using phosphorous oxychloride produced 4-chlorocycloalka[5′,6′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine derivatives 9a-f which were used as key intermediates in the synthesis of several new cycloalkapyrido-thienopyrimidines 10a-f˜14a-f. Moreover, some cycloalkapyridothienotriazinones 15a,b-17a,b were synthesized.