Hydrochloric Acid → 2'-Methyl-2-oxo-1,2-dihydro-3,4'-bipyridine-6-carboxylic acid, hydrochloride salt

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Reaction Steps

Methyl 2-methoxy-2′-methyl-3,4′-bipyridine-6-carboxylate (C32) (1.25 g, 4.84 mmol) was dissolved in dioxane (40 mL) and aqueous hydrochloric acid (37%, 40 mL), and heated to reflux for 18 hours. The reaction was cooled and concentrated to dryness, azeotroped with toluene and methanol and again concentrated to dryness. This process was repeated twice and the resulting solid was triturated three times with a 1:2:0.5 mixture of ethyl acetate/heptane/methanol to give the title compound as a yellow solid. Yield: 1.30 g, 4.87 mmol, quantitative. LCMS m/z 231.1 (M+1). 1H NMR (400 MHz, DMSO-d6) δ 2.76 (s, 3H), 7.08 (d, J=7.3 Hz, 1H), 8.24 (d, J=7.3 Hz, 1H), 8.31-8.38 (m, 2H), 8.76 (d, J=6.0 Hz, 1H), 12.2 (v br s, 1H).

Provenance & Evidence