Heterocycles. CXLII. Synthesis of some triazoloazine 3‐oxides

Abstract

The formation of 3‐oxides of triazolopyridine, triazolopyridazine and triazolopyrazine was investigated. The corresponding 3‐oxides were obtained by oxidative cyclization of 2‐hydroxy‐iminomethyleneaminoazines and some transformations are described.

Heterocycles. 168. Neighboring group interaction in ortho-substituted aminopyridines. Pyridopyrimidines and related systems

“…Found: C, 52.91; H, 4.36; N, 31.13. If the hydrazide was treated with sodium nitrite in dilute aqueous acetic acid the corresponding azido compound (14) could be obtained: mp 135-140 °C (lit.34 mp 116 °C); NMR (Me2SO-d6) 8.75 (dd, H4, Ji 5 = 9.5, J4 s = 1-8 Hz), 8.25 (dd, H5, J5.6 = 4.5 Hz), 9.28 (dd, H6); IR 4.68 (Na), 5.96 µ (CO); MS m/e 163 (M), 135 (M -N2). At the melting point temperature, the compound is transformed into imidazo [4,[5][6]pyrimidin-2-one (3), obtainable also by heating the azido compound in diethvlene glycol dimethyl ether for 30 min, mp 275-273 °C (lit.34 mp 270-272 °C).…”