Tributylphosphine → ethyl(2-{5-(2-methoxyethoxy)-7-[methyl(2-thienylsulfonyl)amino]-1H-indol-2-yl}-4,5-dihydro-1,3-thiazol-5-yl)acetate

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-(2-methoxyethoxy)-7-[methyl(2-thienylsulfonyl)amino]-1H-indole-2-carboxamide (920 mg), Lawesson's reagent (690 mg) and tetrahydrofuran (20 mL) was stirred at 50° C. for 2 hr. The reaction mixture was concentrated, and the residue was subjected to silica gel column chromatography, and eluted with hexane-ethyl acetate (2:1-1:9, volume ratio) to give a yellow amorphous solid. A mixture of the obtained amorphous solid, ethyl but-2-ynoate (620 mg), tributylphosphine (450 mg), toluene (30 mL) and tetrahydrofuran (15 mL) was stirred at 50° C. for 1 hr. The reaction mixture was concentrated, and the residue was subjected to silica gel column chromatography, and eluted with hexane-ethyl acetate (4:1-1:1, volume ratio). The obtained compound was further subjected to silica gel column chromatography, and eluted with hexane-ethyl acetate (1:1, volume ratio) to give the title compound (500 mg, yield 42%) as a yellow oil

Provenance & Evidence