Citric Acid → HCID 57901839, compound

Participants

Reaction Steps

A solution of N-methoxy-N-methyl-7-[(2-thienylsulfonyl)amino]-1H-indole-2-carboxamide (160 mg) in anhydrous tetrahydrofuran (10 mL) was cooled to −70° C. under nitrogen atmosphere. A solution (1.8 mL) of 1.2M-methyllithium in diethyl ether was added dropwise. The temperature of the solution was gradually raised from −70° C. to 0° C., and the mixture was stirred for 4 hr. The reaction mixture was poured into aqueous citric acid solution, and the mixture was extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue was subjected to silica gel column chromatography (ethyl acetate:hexane=1:10-3:7), and the obtained crystals were washed with ethyl acetate-hexane to give the title compound (22 mg, yield 16%) as colorless crystals. melting point 241-243° C.

Provenance & Evidence