Hydrochloric Acid → 6-bromo-1-(1-methylethyl)-1H-indole-4-carboxylic acid

Participants

Reaction Steps

To a solution of methyl 6-bromo-1-(1-methylethyl)-1H-indole-4-carboxylate (0.52 g, 1.756 mmol) in methanol (15 mL) and tetrahydrofuran (3 mL) was added 3 M NaOH (1.756 mL, 5.27 mmol) via syringe drop wise (over 2 min). The solution was maintained at RT for 2 h, at which time LCMS showed only 12% conversion to product. Then 1.5 mL 3 M NaOH was added and the solution was maintained at RT overnight. LCMS showed complete conversion to product. Removed volatiles in vacuo and dissolved the residue in water and slowly acidified with 1 M HCl (solids precipitated). Extracted with EtOAc (2×), combined organics and dried over MgSO4. Filtered and concentrated in vacuo to give 6-bromo-1-(1-methylethyl)-1H-indole-4-carboxylic acid (0.50 g, 1.737 mmol, 99% yield) as a white solid.

Provenance & Evidence