Sodium cyanoborohydride → 6-Bromo-2,3-dihydro-5-methyl-1H-indole

HRID 1887203Notes

Reaction equation

HRID 1887203 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]=[CH:7][NH:8]2)=[CH:4][C:3]=1[CH3:11].[BH3-]C#N.[Na+]>CC(O)=O>[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH2:6][CH2:7][NH:8]2)=[CH:4][C:3]=1[CH3:11]

Participants

4

Reactant 2

HCID 5003444Sodium cyanoborohydrideHCID 107509266-bromo-5-methyl-1H-indole

Product 1

HCID 189409186-Bromo-2,3-dihydro-5-methyl-1H-indoleYield 71.1%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
-10 °C

Procedure

A solution of 6-bromo-5-methylindole (1.00 g, 4.75 mmol) in AcOH (150 mL) was treated with NaBH3CN (0.897 g, 14.3 mmol) while maintaining a temperature of −10° C. The mixture was then stirred at RT overnight and concentrated. The resulting residue was treated with aqueous K2CO3, and extracted with DCM (3×100 mL). The combined organic layers were dried over MgSO4, concentrated and purified by column chromatography (0-75% EtOAc/hexanes) to afford 6-bromo-5-methylindoline (13A, 716 mg).

Workup

  1. concentrationconcentrated
  2. additionThe resulting residue was treated with aqueous K2CO3
  3. extractionextracted with DCM (3×100 mL)
  4. dry with materialThe combined organic layers were dried over MgSO4
  5. concentrationconcentrated
  6. custompurified by column chromatography (0-75% EtOAc/hexanes)

Sources & evidence

ORD record
ord-828da0fa6ef946e282415e803e7bdf80
Source dataset
uspto-grants-2013_08
Patent number
US08501747B2

Reaction notes

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