Trifluoroacetic acid → ethyl 2-(3-(2-(cyclohexylsulfonyl)benzyl)-5-fluoro-2-methyl-1H-indol-1-yl)acetate

Participants

Reaction Steps

To a stirred solution of [5-fluoro-2-methyl-1H-indol-1-yl]acetic acid ethyl ester (0.85 g, 3.62 mmol) at room temperature in dichloromethane (20 mL) was added 2-(cyclohexylsulfonyl)benzaldehyde (1.00 g, 3.97 mmol) followed by triethylsilane (2.9 mL, 18.3 mmol). TFA (0.85 mL, 11.0 mmol) was then added dropwise over 15 minutes, and after the addition was complete, the resulting mixture was stirred for 2 hours. Saturated aqueous NaHCO3 was then added to the solution, and the separated organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo. The resulting solid was purified by trituration with light petroleum then recrystallised from an ethyl acetate/hexanes mixture to afford ethyl 2-(3-(2-(cyclohexylsulfonyl)benzyl)-5-fluoro-2-methyl-1H-indol-1-yl)acetate (0.875 g, 1.86 mmol, 51%).

Provenance & Evidence