Tetrahydrofuran → HCID 19092856, compound

Participants

Reaction Steps

N,N-Dimethylformamide (3 drops) and oxalyl chloride (0.59 ml) were added to a solution of 5,6-dimethoxy-3-(3,4-dimethoxyphenyl)indole-2-carboxylic acid (2.0 g) in tetrahydrofuran (50 ml). The mixture was stirred for an hour at room temperature and concentrated under reduced pressure. The residue was dissolved in benzene (20 ml). This benzene solution was added to a solution of tert-butanol (0.79 ml) and N,N-dimethylaniline (0.85 ml) in benzene (30 ml), followed by stirring overnight at room temperature. The mixture was successively washed with water, sodium hydrogen carbonate saturated aqueous solution and water, dried (MgSO4) and concentrated. The precipitated crystals were collected by filtration and recrystallized from acetone to give tert-butyl 5,6-dimethoxy-3-(3,4-dimethoxyphenyl)indole-2-carboxylate (1.61 g, 70%) as colorless prisms.

Provenance & Evidence