Benzyl Bromide → 4-[N-benzyl-N-(2-methoxycarbonyl-1-methylethyl)aminoacetyl]-7-benzyloxyindole-2-carboxylic acid ethyl ester

Participants

Reaction Steps

48.8 g of 4-[N-benzyl-N-(2-methoxycarbonyl-1-methylethyl)aminoacetyl]-7-hydroxyindole-2-carboxylic acid ethyl ester hydrochloride, 41.4 g of potassium carbonate, and 25 ml of benzyl bromide are heated under reflux for 6 hours in 900 ml of acetone. After cooling, the reaction mixture is concentrated to dryness, the residue is taken up in ethyl acetate and saturated sodium bicarbonate solution, the organic phase is separated and extracted three times with saturated sodium bicarbonate solution. The organic phase is washed with water, dried, concentrated, and the residue is recrystallized from ethyl acetate/n-hexane, thus obtaining 42.5 g of 4-[N-benzyl-N-(2-methoxycarbonyl-1-methylethyl)aminoacetyl]-7-benzyloxyindole-2-carboxylic acid ethyl ester, mp 120°-123° C.

Provenance & Evidence