Synthesis and Properties of Partially Hydrogenated Ethyl ([3,4']Bipyridin-6'-ylsulfanyl) Acetates

Synthesis and Properties of Partially Hydrogenated Ethyl ([3,4']Bipyridin-6'-ylsulfanyl) Acetates Ethyl 2'-hydroxy-1',2',3',4'-tetrahydro[3,4']bipyridine-3'-carboxylate 3 and the corresponding ethyl 1',4'-dihydro[3,4']bipyridine-3'-carboxylate 4 as potential cardiovascular agents have been prepared by alkylation of 2'-hydroxy-1',2',3',4'-tetrahydro[3,4']bipyridine-6'-thiolate 1 or betaine 2 with ethyl bromoacetate. The treatment of [3,4']bipyridine 4 with KOH/H 2 O gave diethyl 3-amino-4-(pyridin-3-yl)-4,7-dihydrothieno[2,3- b ]-pyridine-2,5-dicarboxylate 5 , but subsequent treatment of the remaining reaction mixture with acetic acid excess gave ethyl 3-oxo-7-(pyridin-3-yl)-2,3-dihydro-7H-thiazolo[3,2- a ]pyridine-6-carboxylate 7 - the product of intramolecular acylation. Compounds 4, 5 and 7 have been prepared using the one-pot synthesis method. Alkylation of [3,4']bipyridine 4 with iodomethane gave 1',4'-dihydro[3,4'] bipyridin-1-ium iodide 8 .