Furopyridines. XXIII [1]. Synthesis and Reactions of Chloropyridine Derivatives of Furo[2,3-b]-, -[2,3-c]- and -[3,2-c]pyridine

Article abstract of DOI:10.1002/jhet.5570340333

Chlorination of the N-oxides of furo[2,3-b]- 1a, -[2,3-c]- 1b and -[3,2-c]pyridine 1c with phosphorus oxychloride afforded compounds substituted normally at the α- or γ-position to the ring nitrogen, 2a, 2′a, 2b, 2c, 2′c and 2″c, and in addition, in the case of 1b, compounds substituted on the furan ring, 2′b and 2″b. The structures of these compounds were confirmed from their ir, nmr and mass spectra. The major chlorinated products 2a, 2b and 2c were converted to methoxy- 5a, 5b and 5c, N-pyrrolidyl- 7a, 7b and 7c, and phenylthiofuropyridines 8a, 8b, and 8c.