Citric Acid → {2-[7-[(2-thienylsulfonyl)amino]-5-(trifluoromethoxy)-1H-indol-2-yl]-4,5-dihydro-1,3-thiazol-5-yl}acetic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl {2-[7-[(2-thienylsulfonyl)amino]-5-(trifluoromethoxy)-1H-indol-2-yl]-4,5-dihydro-1,3-thiazol-5-yl}acetate (780 mg), 1N aqueous sodium hydroxide solution (5 mL), tetrahydrofuran (5 mL) and ethanol (5 mL) was stirred at 50° C. for 30 min. The reaction mixture was acidified with aqueous citric acid solution, and extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4), and concentrated. The residue was crystallized from ethyl acetate-diisopropyl ether to give the title compound (490 mg, yield 64%) as brown crystals. The crystals were recrystallized from ethyl acetate-hexane to give brown prism crystals. melting point 247-248° C. (decomposition).

Provenance & Evidence