Hydrazine hydrate (1:1) → Pyrido(2,3-d)pyridazine-5,8-diol

Participants

Reaction Steps

Hydrazine hydrate (13.09 g, 0.261 mol) was added to a stirred solution of pyridine-2,3-dicarboxylic anhydride (30.0 g, 0.201 mol) and sodium acetate (21.45 g, 0.261 mol) in 40% acetic acid/water (400 ml). The reaction was heated at reflux for 3 days under nitrogen. The yellow precipitate was filtered off and washed successively with water (4×200 ml), hexane (3×150 ml) and diethyl ether (3×150 ml) to give the title-compound (25.0 g, 76%), 1H NMR (250 MHz, d6-DMSO) δ 7.90 (1H, q, J=4.5Hz, Ar—H), 8.51 (1H, d, J=4.5Hz, Ar—H), 9.13 (1H, d, J=4.6Hz, Ar—H), 11.65 (2H, br s, 2 of NH); MS (ES+) m/e 164 [MH]+.

Provenance & Evidence