Sodium Hydroxide → HCID 58691599, compound

Participants

Reaction Steps

A solution of methyl 4-(3-phenylpyrazolo[1,5-a]pyrimidin-6-yl)thiophene-2-carboxylate (5-2, 2.0 g, 6.0 mmol, 1 equiv) in a mixture of aqueous sodium hydroxide solution (1N, 18 mL, 18 mmol, 3.0 equiv) and n-BuOH (100 mL) was heated at reflux for 1 hour. The reaction mixture was concentrated, and the residue was suspended in aqueous 1 N hydrogen chloride solution (100 mL) and filtered. The filtered solid was washed with water and dried to give 4-(3-phenylpyrazolo[1,5-a]pyrimidin-6-yl)thiophene-2-carboxylic acid (5-3). 1H NMR (400 MHz, DMSO-d6) δ 9.68 (d, 1H, J=2.4 Hz), 9.15 (d, 1H, J=2.2 Hz), 8.79 (s, 1H), 8.48 (d, 1H, J=1.6 Hz), 8.41 (d, 1H, J=1.6 Hz), 8.16 (br d, 1H, J=7.8 Hz), 7.46 (br t, 2H, J=7.8 Hz), 7.26 (t, 1H, J=7.5 Hz).

Provenance & Evidence