Citric Acid → N-methyl-N-{2-[5-(2-oxobut-3-en-1-yl)-4,5-dihydro-1,3-thiazol-2-yl]-1H-indol-7-yl}thiophene-2-sulfonamide

Participants

Reaction Steps

N-Methoxy-N-methyl-2-(2-{7-[methyl(2-thienylsulfonyl)amino]-1H-indol-2-yl}-4,5-dihydro-1,3-thiazol-5-yl)acetamide (589 mg) was dissolved in absolute tetrahydrofuran (20 mL), and 1M vinylmagnesium bromide tetrahydrofuran solution (3.7 mL) was added under ice-cooling. The mixture was stirred for 5 hr under ice-cooling, 1M vinylmagnesium bromide tetrahydrofuran solution (2.0 mL) was added again, and the mixture was further stirred under ice-cooling for 2 hr. The reaction solution was acidified with aqueous citric acid solution, and extracted with ethyl acetate. The organic layer was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue was subjected to silica gel column chromatography (ethyl acetate), and the obtained pale-yellow crystals were washed with ethyl acetate-hexane to give the title compound (210 mg, yield: 38%) as pale-yellow crystals. MS: 446 (MH+). melting point 157-158° C.

Provenance & Evidence