Sodium cyanoborohydride → 3-benzyl-7-bromo-1H-indole-2-carboxylic acid ethyl ester

HRID 18173

Reaction equation

HRID 18173 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([C:14]=1[C:15](=O)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[CH:12][CH:11]=[CH:10][C:9]=2[Br:23])=[O:5])[CH3:2].[BH3-]C#N.[Na+].CCOC(C)=O.O>ClCCCl.[Zn+2].[I-].[I-]>[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([C:14]=1[CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[CH:12][CH:11]=[CH:10][C:9]=2[Br:23])=[O:5])[CH3:2]

Participants

6

Reactant 3

HCID 5003444Sodium cyanoborohydrideHCID 22728543Water ethylacetateHCID 593449273-benzoyl-7-bromo-1H-indole-2-carboxylic acid ethyl ester

Product 1

HCID 593449063-benzyl-7-bromo-1H-indole-2-carboxylic acid ethyl esterYield 30.1%

Reagents, catalysts & solvents 2

HCID 9883512zinc(II)iodideCatalystHCID 111,2-DichloroethaneSolvent

Procedure

To a solution of 3-benzoyl-7-bromo-1H-indole-2-carboxylic acid ethyl ester (2.4 g, 6.45 mmol) in 1,2-dichloroethane (80 ml) was added NaBH3CN (3.24 g, 51.6 mmol) and ZnI2 (6.18 g, 19.4 mmol). After stirring at room temperature for 30 minutes, the reaction mixture was poured into a mixture of EtOAc/H2O. The organic layer was separated and washed with water and brine. After drying over MgSO4, the organic fraction was concentrated in vacuo and the resulting residue was purified by flash chromatography to give 3-benzyl-7-bromo-1H-indole-2-carboxylic acid ethyl ester as yellow solid (696 mg, 30%). 1H NMR (CDCl3, 300 MHz) δ: 1.39 (t, 3H, J=7.13 Hz), 4.43 (q, 2H, J=7.13 Hz), 4.49 (s, 2H), 6.98 (t, 1H, J=7.8 Hz), 7.22 (m, 5H), 7.46 (d, 1H, J=7.60 Hz), 7.54 (d, 1H, J=8.10 Hz).

Workup

  1. customThe organic layer was separated
  2. washwashed with water and brine
  3. dry with materialAfter drying over MgSO4
  4. concentrationthe organic fraction was concentrated in vacuo
  5. customthe resulting residue was purified by flash chromatography

Sources & evidence

ORD record
ord-3a11ac495ff34ddc92b9eeca27037eda
Source dataset
uspto-grants-2010_06
Patent number
US07741326B2

Linked notes

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