STUDIES WITH POLYFUNCTIONALLY SUBSTITUTED HETEROAROMATICS, A NEW ROUTE TO SYNTHESIS OF THIOPYRANO[3,2-C]PYRIDINE, THIOPYRANO[4,3-B]PYRIDINE, AND BIPYRIDYL DERIVATIVES

Pyridine derivatives (4a, d, e) were reacted with carbon disulflde in dry tetrahydrofurane (THF) in the presence of potassium tert-butoxide under Argon to yield thiopyanopyridine derivatives (7, 10). Also (2a, 4c) were reacted with carbon disulfide under the same condition produc ing the dithioacetal derivatives (13) which were converted to bipyridy l derivatives (14) via reaction with cyanorhioacetamide in isopropyl a lcohol and sodium isopropoxide.