Hydrochloric Acid → 2-Ethylpyrazolo[1,5-a]pyridine-3-carboxylic acid

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Reaction Conditions

Reaction Steps

Ethyl 2-ethylpyrazolo[1,5-a]pyridine-3-carboxylate (5.0 g, 23 mmol) was stirred in methanol (200 mL) and a solution of sodium hydroxide in water (100 mL, 3 N) was added. The mixture was heated at 60° C. for 16 h. Evaporation gave a thick suspension which was treated with aqueous hydrogen chloride (100 mL, 3 N). The solids briefly dissolved and a new precipitate formed. The solid was filtered and washed with water to give the desired compound (4.1 g, 96%). LCMS for C10H11N2O2 (M+H)+: m/z=191.1. 1H NMR (300 MHz, DMSO-d6): δ 8.52 (m, 1 H), 8.15 (m, 1 H), 7.23 (m, 1 H), 6.81 (m, 1 H), 3.05 (m, 2 H), 1.22 (m, 3 H).

Provenance & Evidence