Hydrochloric Acid → HCID 20203551, compound

Participants

Reaction Steps

Anhydrous potassium carbonate (34.5 g, 0.25 mol) was added to a solution of 6-methoxy-3-methylindole (16.1 g, 0.1 mol) and γ-butyrolactone (43 g, 0.5 mol) in dimethylacetamide (750 mL). Under mechanical stirring and protected with a drying tube, the reaction mixture was refluxed for 18 hours, more γ-butyrolactone (21.5 g, 0.25 mol) was added, and the reflux was continued for 12 hours. A final portion of γ-butyrolactone (21.5 g, 0.25 mol) was added and the thick suspension was refluxed for another 12 hours, cooled to ~30° C., and poured into water (600 mL). Toluene (600 mL) was added and the 2 layer system was stirred for 15 minutes. The aqueous layer was separted and acidified with concentrated hydrochloric acid. The product was extracted with toluene (3×250 mL). The combined extracts were washed with water (600 mL), dried over MgSO4, filtered, evaporated, and the dark oily residue was chromatographed on silica gel (480 g). Elution with chloroform/hexane (1:1) afforded 18.2 g (74%) of the title compound as a yellowish oil.

Provenance & Evidence