Hydrochloric Acid → 1H-indazole-6-carboxylic acid

Participants

Reaction Steps

To a stirred solution of potassium tert-butoxide (8.14 g, 72.7 mmol) in DMSO (30 mL) is added a solution of 3-(tert-butylthio)diazenyl-4-methylbenzoic acid (1.85 g, 7.34 mmol) in DMSO (20 mL). The mixture is stirred overnight at rt. The mixture is diluted with ice-water, acidified with 1N aqueous HCl to a pH of about 5 to about 6 and extracted with EtOAc (3×). The combined organic layers are washed sequentially with water and brine, dried over MgSO4 and concentrated in vacuo to afford 1.17 g (98%) of 1H-indazole-6-carboxylic acid as a tan solid: IR (diffuse reflectance) 3171, 3135, 3067, 3014, 2950, 2889, 2865, 1685, 1326, 1308, 1240, 960, 945, 762, 740 cm−1; 1H NMR (400 MHz, DMSO-d6) δ 13.4, 13.0, 8.2, 8.2, 7.9, 7.7.

Provenance & Evidence