Water → tert-butyl 6-(2-hydroxyethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate

HRID 2306952Notes

Reaction equation

C([O:3][C:4](=O)[CH2:5][N:6]1[C:14]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[C:8]2[CH2:15][CH2:16][N:17]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:18][CH2:19][C:7]1=2)C.[Li+].[BH4-].O>C1COCC1>[OH:3][CH2:4][CH2:5][N:6]1[C:14]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[C:8]2[CH2:15][CH2:16][N:17]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:18][CH2:19][C:7]1=2

Participants

Conditions

Temperature: -10 °C

Procedure

tert-Butyl 6-(2-ethoxy-2-oxoethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate (0.602 g, 1.62 mmol) was dissolved in THF (15 mL), and the resulting solution was cooled to −10° C. under N2. LiBH4 (0.0756 g, 3.47 mmol, 2.14 equiv.) was added and the reaction mixture was allowed to warm to rt. After 19.5 h, the reaction mixture was cooled to 0° C., and LiBH4 (0.0250 g, 1.15 mmol, 0.71 equiv.) was added and the reaction mixture was allowed to warm up for 3.5 h. The reaction mixture was combined with water and was extracted with EtOAc (2×). The combined organic layers was washed with brine, dried over MgSO4, filtered, and concentrated to give tert-butyl 6-(2-hydroxyethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate (0.533 g) in acceptable purity and essentially quantitative yield. 1H NMR (300 MHz, CD3OD) δ 1.48-1.51, 3.00-3.11, 3.66-3.79, 3.87-3.95, 4.27, 7.12, 7.19, 7.32, 7.50; MS (ESI+) for C19H26N2O3 m/z 331.2 (M+H)+.

Workup

temperatureto warm to rt
temperaturethe reaction mixture was cooled to 0° C.
temperatureto warm up for 3.5 h
extractionwas extracted with EtOAc (2×)
washThe combined organic layers was washed with brine
dry with materialdried over MgSO4
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-d0a76644ba2c4e1a88bc99df11c0a89c
Source dataset: uspto-grants-2004_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06828314B2

Reaction notes

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