Water → 5-Oxo-4,5-dihydro-pyrazolo[1,5-a]pyriMidine-3-carboxylic acid

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Reaction Steps

A solution of methyl 5-oxo-4,5-dihydropyrazolo[1,5-c]pyrimidine-3-carboxylate (0.75 g 3.89 mM, 1.0 equiv), lithium hydroxide (0.466 g, 19.4 mM, 5.0 equiv) and 20 mL of water was stirred at ambient temperature for 3 hours. HPLC indicated complete reaction. Acetic acid (5 mL) was added and the precipitated solid was collected by vacuum filtration to give 0.65 g (93%) 5-oxo-4,5-dihydropyrazolo[1,5-a]pyrimidine-3-carboxylic acid. 1H NMR (400 MHz, DMSO-d6) δ: 12.5 (br s, 1H,), 11.3 (br s, 1H), 8.57 (d, 1H), 8.08 (d, 1H), 6.15 (d, 1H).

Provenance & Evidence