Cyclohexanone → 3-(Cyclohex-1-en-1-yl)-1H-indole-6-carboxylic acid

Participants

Reaction Steps

Cyclohexanone (96 mL, 0.926 mol) was added to a stirred solution of methyl indole-6-carboxylic acid (50.0 g, 0.335 mol) in methanol (920 mL) at 22° C. Methanolic sodium methoxide (416 mL of 25% w/w, 1.82 mol) was added in portions over 10 minutes. The mixture was stirred at reflux for 18 hours, cooled to room temperature, concentrated, diluted with cold water, and acidified with 36% HCl solution. The resulting precipitate was collected by filtration, washed with cold water, and dried over phosphorous pentoxide (0.1 mm) to provide the title compound as a tan colored solid (80.9 g, 97.5% yield).

Provenance & Evidence