Tetrahydrofuran → 6-Bromo-1-isopropyl-1H-indazole-4-carboxylic acid

Participants

Reaction Steps

To a solution of 6-bromo-1-(1-methylethyl)-1H-indazole-4-carboxylate (0.58 g, 1.952 mmol in methanol (12 mL) and tetrahydrofuran (3 mL) was added 3 N NaOH (3.25 mL, 9.76 mmol) via syringe and stirred for 3 h at RT. The volatiles were removed in vacuo then diluted with water and slowly acidifed with 1 N HCl to pH 4-5. The contents were extracted with 20% THF/EtOAc (3×). The combined organics were washed with brine, dried over MgSO4, filtered, and concentrated to give 6-bromo-1-(1-methylethyl)-1H-indazole-4-carboxylic acid (0.52 g, 94% yield). 1H NMR (400 MHz, DMSO-d6) d ppm 13.54 (s, 1H) 8.36-8.43 (m, 2H) 7.82 (d, J=1.52 Hz, 1H) 5.11 (quin, J=6.57 Hz, 1H) 1.48 (s, 3H) 1.47 (s, 3H); LC-MS(ES) [M+H]+ 283.4/285.2

Provenance & Evidence