5-(Trifluoromethyl)indole

1217302-64-1

100846-24-0

Step 5 Synthesis of 5-(trifluoromethyl)indole To a 250 mL three-necked round-bottomed flask was added N-[2-(3,3-dimethyl-3-silyl-1-ynyl)-4-(trifluoromethyl)phenyl]ethoxycarboxamide (31.5 g, 0.1 mol), EtONa (32.5 g, 0.48 mol) and anhydrous ethanol (200 mL). The reaction mixture was heated to reflux and kept for 2 hours. After completion of the reaction, the mixture was concentrated under reduced pressure. The residue was purified by fast column chromatography on silica gel, using a petroleum ether solution of 25% ethyl acetate as eluent to give 14 g (77% yield) of the target product 5-(trifluoromethyl)indole. 1H NMR (300 MHz, DMSO-d6) δ: 8.36 (s, 1H), 7.96-7.94 (m, 1H), 7.46-7.44 (m, 2H), 7.32-7.30 (m, 1H), 6.66-6.64 (m, 1H).