Hydrochloric Acid → 3-methyl-1-(1-methylethyl)-6-(methyloxy)-1H-indole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To methyl 6-bromo-3-methyl-1-(1-methylethyl)-1H-indole-4-carboxylate (1.3 g, 4.19 mmol) and copper(I) iodide (1.0 g, 5.25 mmol) was added NMP (8 mL). To the mixture was added dropwise a solution of sodium methoxide 25 wt % in methanol (4.0 mL, 17.49 mmol) with stirring. The reaction was heated to 120° C. and stirred for 1.5 hr. The reaction was allowed to cool and when the temperature reached 80° C., water (200 uL) was added. The reaction was allowed to continue to cool to RT and stirred overnight. The reaction was acidified with 1 N HCl (17 mL) and diluted with water and EtOAc. The mixture was filtered through Celite and washed with EtOAc. The filtrate was poured into a separatory funnel and the organic phase was separated, washed with brine, dried (MgSO4), filtered, and concentrated under vacuum. Purification by silica gel chromatography (Analogix, SF25-60 g, 20 to 50% EtOAc in hexanes) gave after concentration, trituration with hexanes, filtration and drying under vacuum 3-methyl-1-(1-methylethyl)-6-(methyloxy)-1H-indole-4-carboxylic acid (825 mg, 3.34 mmol, 80% yield) as an light yellow solid. MS(ES)+ m/e 248.3 [M+H]+.

Provenance & Evidence