Ethyl Acetate → tert-Butyl 9,10-dichloro-6-(2-hydroxyethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate

HRID 2307010Notes

Reaction equation

HRID 2307010 reaction equation
[Cl:1][C:2]1[CH:10]=[CH:9][C:8]2[N:7]([CH2:11][C:12](OCC)=[O:13])[C:6]3[CH2:17][CH2:18][N:19]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:20][CH2:21][C:5]=3[C:4]=2[C:3]=1[Cl:29].[Li+].[BH4-].[OH-].[Na+].CCOC(C)=O>C1COCC1.O>[Cl:1][C:2]1[CH:10]=[CH:9][C:8]2[N:7]([CH2:11][CH2:12][OH:13])[C:6]3[CH2:17][CH2:18][N:19]([C:22]([O:24][C:25]([CH3:27])([CH3:26])[CH3:28])=[O:23])[CH2:20][CH2:21][C:5]=3[C:4]=2[C:3]=1[Cl:29]

Participants

7

Reactant 4

HCID 8857Ethyl AcetateHCID 14798Sodium HydroxideHCID 4148881Lithium borohydrideHCID 22396818tert-Butyl 9,10-dichloro-6-(2-ethoxy-2-oxoethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate

Product 1

HCID 22396738tert-Butyl 9,10-dichloro-6-(2-hydroxyethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylateYield 21%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution tert-butyl 9,10-dichloro-6-(2-ethoxy-2-oxoethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate (1.0 g, 2.3 mmol) in dry THF (10 mL) was cooled to 0° C. Then, LiBH4 (0.15 g, 6.8 mmol) was added and the reaction was allowed to warm slowly to rt. After 4 h, the reaction was diluted with H2O followed by addition of 10% aqueous NaOH and extraction with EtOAc (3×50 mL). The combined organic extracts were washed with brine, dried over Na2SO4, decanted, and concentrated. The crude product was purified by column chromatography (Biotage, 40M, SIM) with heptane/EtOAc (1:1) followed by crystallization from EtOAc/heptane gave 0.19 g (21%) of a white solid: mp 174.5-176.0° C.; IR (diffuse reflectance) 3419, 1662, 1466, 1447, 1424, 1370, 1359, 1275, 1248, 1170, 1157, 1120, 1078, 933, 799cm−1; MS (EI) m/z 398 (M+), 400, 398, 344, 342, 341, 268, 86, 84, 57, 51; Anal. Calcd for C19H24Cl2N2O3: C, 57.15; H, 6.06; N, 7.01; found: C, 57.13; H, 6.13; N, 6.9.

Workup

  1. washThe combined organic extracts were washed with brine
  2. dry with materialdried over Na2SO4
  3. customdecanted
  4. concentrationconcentrated
  5. customThe crude product was purified by column chromatography (Biotage, 40M, SIM) with heptane/EtOAc (1:1)
  6. customfollowed by crystallization from EtOAc/heptane

Sources & evidence

ORD record
ord-f811ba41a4b748a9abe1b8edf63fa8e9
Source dataset
uspto-grants-2004_12
Patent number
US06828314B2

Reaction notes

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