5-bromo-6-chloro-2-(ethoxycarbonyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acid → ethyl 5-bromo-8-carbamoyl-6-chloro-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate

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Reaction Steps

Following the procedure used to prepare Intermediate 24D, 5-bromo-6-chloro-2-(ethoxycarbonyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acid was converted into ethyl 5-bromo-8-carbamoyl-6-chloro-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate as a light brown solid (8.54 g, 78% yield). Mass spectrum m/z 399, 401 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 13.44 (br. s., 1H), 11.24 (s, 1H), 7.69 (s, 1H), 4.12 (qd, J=7.1, 2.3 Hz, 2H), 3.23-2.81 (m, 5H), 2.23-2.09 (m, 1H), 1.91-1.75 (m, 1H), 1.22 (t, J=7.0 Hz, 3H).

Provenance & Evidence