Citric Acid → HCID 59136038, compound

Participants

Reaction Steps

To a solution of N-ethyl-N-[2-(5-formyl-1,3-thiazol-2-yl)-4-methyl-1H-indol-7-yl]thiophene-2-sulfonamide (1.3 g) in a mixed solvent of methanol (15 ml) and tetrahydrofuran (40 ml) was added sodium borohydride (0.14 g) under ice-cooling, and the mixture was stirred at the same temperature for 2 hr. Aqueous citric acid solution was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained crystals were washed with ethyl acetate-hexane to give the title compound (0.74 g) as pale-yellow crystals. The mother liquor was concentrated, and the residue was subjected to silica gel column chromatography (ethyl acetate:hexane=3:7-6:4) to give the title compound (0.20 g) as pale-yellow crystals. total yield 0.94 g (yield 72%). melting point 166-167° C.

Provenance & Evidence