Water → 2-Ethyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester

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Reaction Steps

A solution of 1-aminopyridinium iodide (10 g, 40 mmol) [Aldrich 441503], ethyl 2-pentynoate (5.7 g, 45 mmol) [Aldrich 632112] and potassium carbonate (12.0 g, 90 mmol) were stirred in N,N-dimethylformamide (200 mL) at 20° C. for 16 h. The mixture was poured into water to give a tan suspension. The solid was filtered and washed with water to give the desired compound (5.0 g, 57%). LCMS for C12H15N2O2 (M+H)+: m/z=219.1. 1H NMR (300 MHz, DMSO-d6): δ 8.77 (m, 1 H), 8.00 (m, 1 H), 7.52 (m, 1 H), 7.05 (m, 1 H), 4.28 (m, 2 H), 3.00 (m, 2 H), 1.33 (m, 3 H), 1.24 (m, 3 H).

Provenance & Evidence