Furopyridines. XXVII. Reactions of 2-methyl and 2-cyano derivatives of furo[2,3-b]-, -[3,2-b]-, -[2,3-c]- and -[3,2-c]pyridine

Bromination of 2-methylfuropyridines 1a-d-Me gave the 3-bromo derivatives 2 a-d, while the 2-cyano compounds 1a-d-CN resulted in the recovery of the st arting compounds. Nitration of 1a-d-Me and la-d-CN did not yield the corres ponding nitro derivative, except for 1-c-CN giving 3-nitro derivative 3c in 7% yield. N-Oxidation of 1a-d-Me and 1b-d-CN with m-chloroperbenzoic acid yielded the N-oxides 4a-d-Me and 4b-d-CN, whereas la-CN did not afford the N-oxide. Cyanation of N-oxides 4a-d-Me and 4b-d-CN with trimethylsilyl cyan ide gave the corresponding alpha-cyanopyridine compounds 5a-d-Me and 5b-d-C N, Chlorination of 4a-d-Me and 4b-d-CN with phosphorus oxychloride also gav e the alpha-chloropyridine compounds 6b-d-Me and 6b-d-CN, accompanying form ation of gamma-chloropyridine 6a-Me, 6'b-Me and 6'b-CN, beta-chloropyridine 6 " b-CN, and alpha'-chloropyridine derivatives 6'c-Me and 6'c-CN, Acetoxy lation of 4a-d-Me and 4b-d-CN with acetic anhydride yielded alpha-acetoxypy ridine compounds 7a-Me and 7b-CN, pyridone compounds lid-Me, 11c-CN and 11d -CN, 3-acetoxy compounds 8, 9b, 9c, and 2-acetoxymethyl derivatives 10b and 10c.