Trifluoroacetic acid → 13-cyclohexyl-3-methoxy-6-(methoxycarbonyl)-7H-indolo[2,1-a][2]benzazepine-10-carboxylic acid

Participants

Reaction Steps

Trifluoroacetic acid (30 mL) was added dropwise to a stirring slurry of 10-tert-butyl 6-methyl 13-cyclohexyl-3-methoxy-7H-indolo[2,1-a][2]benzazepine-6,10-dicarboxylate (10 g, 20 mmol) in dichloroethane (30 mL) under N2. The clear dark green solution was stirred at rt for 2.5 h, concentrated to dryness and stirred with EtOAc (100 mL) overnight. The solids were collected by filtration, washed with EtOAc and Et2O to yield 13-cyclohexyl-3-methoxy-6-(methoxycarbonyl)-7H-indolo[2,1-a][2]benzazepine-10-carboxylic acid (8.35 g, 18.8 mmol, 94%) was as a yellow solid which was used without further purification. 1HNMR (300 MHz, CDCl3) δ 1.13-2.16 (m, 10H), 2.74-2.88 (m, 1H), 3.84 (s, 3H), 3.89 (s, 3H), 4.06-4.29 (m, 1H), 5.54-5.76 (m, 1H), 6.98 (d, J=2.6 Hz, 1H), 7.08 (dd, J=8.4, 2.6 Hz, 1H), 7.52 (d, J=8.4 Hz, 1H), 7.78 (dd, J=8.8, 1.1 Hz, 1H), 7.80 (s, 1H), 7.86 (d, J=8.8 Hz, 1H), 8.34 (d, J=1.1 Hz, 1H). LCMS: m/e 446 (M+H)+, ret time 3.21 min, column B, 4 minute gradient.

Provenance & Evidence