1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Methyl 4-(2-chloroethyl)-7-hydroxy-2-trifluoromethyl-5-(5,6,7-trimethoxyindole-2-carboxamido)indole-3-carboxylate

Participants

Reaction Steps

10% Pd/C (0.023 g) was added to methyl 7-benzyloxy-4-(2-cloroethyl)-5-nitro-2-trifluoromethylindole-3-carboxylate (0.0468 g, 0.102 mmol) and chilled THF (7 mL) was added quickly to the flask. The mixture was placed under reduced pressure and purged three times with H2. The reaction was stirred under H2 at room temperature and atmospheric pressure until completed by TLC. The solution was filtered through Celite pad in a sinter funnel and washed with THF. The amine was then concentrated under reduced pressure and co-evaporated twice with dry CH2Cl2 (2 mL). To the amine were added EDCI (0.040 g, 0.208 mmol) and 5,6,7-trimethoxyindole-2-carboxylic acid (0.026 g, 0.104 mmol). The flask was covered and flushed with N2. The amine was dissolved in dry DMF (10 mL) and stirred for four days under N2. The yellow solution was then diluted with ethyl acetate (100 mL), washed with water three times (100 mL) and 5% NaHCO3 (75 mL). The organic layer was collected, dried with sodium sulfate, gravity filtered and concentrated under reduced pressure. The residue was then purified on a preparative TLC in 2.5% methanol chloroform to yield the crude product. The product was further purified on a preparative TLC in methylene chloride to yield methyl 4-(2-chloroethyl)-7-hydroxy-2-trifluoromethyl-5-(5,6,7-trimethoxyindole-2-carboxamido)indole-3-carboxylate as a yellow solid. Total yield: 0.001 g (0.002 mmol, 2%). TLC (methylene chloride) Rf320.56.500 MHz 1H-NMR (CDCl3): 9.53 (s, 1H), 9.37 (s, 1H), 9.07 (s, 2H), 7.89 (s, 1H), 7.42 (s, 1H), 6.85 (s, 1H), 4.12 (s, 3H), 4.00 (s, 3H), 3.96 (s, 3H), 3.93 (s, 3H), 3.87 (t, 8.0, 2H), 3.72 (t, 8.0, 2H). IR (Neat) 3018, 2965, 2922, 2847, 1729, 1531, 1472, 1344, 1253, 1227, 1178, 1109, 1002, 799.

Provenance & Evidence