Dimethyl Sulfate → Methyl 3-methoxy-1-phenyl-1H-indole-2-carboxylate

Participants

Reaction Steps

A suspension of 3.9 g (0.081 mole) of 50% sodium hydride/mineral oil in 85 ml of N,N-dimethylformamide under a nitrogen atmosphere was cooled in ice and treated portionwise over 90 minutes with 17.1 g (0.064 mole) of 3-hydroxy-1-phenyl-1H-indole-2-carboxylic acid methyl ester [P. Friedlander and K. Kunz, Chem. Ber., 55, 1597 (1922)]. The mixture was stirred in ice an additional one hour, 7.9 ml (10.5 g; 0.083 mole) of dimethyl sulfate was added dropwise over 15 minutes, the ice bath was removed, and stirring was continued for a total of 65 hours. The reaction mixture was added to 600 g of ice/water, acidified with 4.0N hydrochloric acid, and extracted with dichloromethane (4×250 ml). The combined organic layers were washed with water (3×500 ml), dried (anhydrous sodium sulfate), and evaporated to yield a crude residue of 3-methoxy-1-phenyl-1H-indole-2-carboxylic acid methyl ester, plus a small amount of N,N-dimethylformamide.

Provenance & Evidence