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

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Reaction Steps

13-Cyclohexyl-3-methoxy-7H-benzo[3,4]azepino[1,2-a]indole-6,10-dicarboxylic acid 10-tert-butyl ester 6-methyl ester 1a (1 g, 1 eq) was dissolved in dry dichloromethane under N2, followed by the addition of trifluoroacetic acid (TFA) (8.88 ml, 60 eq). The solution was stirred at RT for 24 h. The solvent was then removed under reduced pressure. The crude product was triturated with diethyl ether. The crystals were filtered off and dried under vacuum overnight to afford the title product 13-Cyclohexyl-3-methoxy-7H-benzo[3,4]azepino[1,2-a]indole-6,10-dicarboxylic acid 6-methyl ester 13a (89%, 0.86 g); LC-MS: Rt. 3.19 min., m/z 446 [M+H]+.

Provenance & Evidence