2-Thiophenesulfonyl chloride → ethyl 4-chloro-1-(methoxymethyl)-7-[(2-thienylsulfonyl)amino]-1H-indole-2-carboxylate

Participants

Reaction Steps

To a mixture of ethyl 7-amino-4-chloro-1-(methoxymethyl)-1H-indole-2-carboxylate (0.91 g) and pyridine (10 ml) was added thiophene-2-sulfonyl chloride (0.50 g) at 0° C., and the mixture was stirred overnight at room temperature. The reaction mixture was concentrated, 10% aqueous citric acid solution was added, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4), and concentrated. The obtained residue was subjected to silica gel column chromatography to give the title compound (1.14 g, yield 83%) as a yellow oil from a fraction eluted with ethyl acetate-hexane (1:2, volume ratio).

Provenance & Evidence