Methanol → 6-oxo-3,4,5,6-tetrahydro-1H-azepino[5,4,3-cd]indole-2-carboxylic acid

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Reaction Steps

6-Oxo-3,4,5,6-tetrahydro-1H-azepino[5,4,3-cd]indole-2-carboxylic acid octyl ester (Example FFF) (350 mg, 1.02 mmol) and lithium hydroxide (122 mg, 5.11 mmol) were dissolved in 10 mL 2:1 methanol:water and stirred at room temperature for 24 h. The reaction mixture was diluted with water then washed twice with dichloromethane. The aqueous solution was acidified to ca. pH 2 with conc. HCl. The white precipitate was collected by filtration, washed with water, and dried in vacuo to yield 6-oxo-3,4,5,6-tetrahydro-1H-azepino[5,4,3-cd]indole-2-carboxylic acid, 235 mg (99%) as a white solid: m.p. 298-299° C. (dec); 1H NMR (300 MHz, d6-DMSO) δ3.17 (m, 2H), 3.41 (m, 2H), 7.35 (t, J=7.8 Hz, 1H), 7.59 (d, J=8.1 Hz, 1H), 7.73 (d, J=7.5 Hz, 1H), 8.14 (br t, 1H), 11.77 (br s, 1H), 13.14 (br s, 1H). MS (electrospray, MH+): 231. Anal. (C12H10N2O3.1.0 H2O)C, H, N.

Provenance & Evidence