Trifluoroacetic acid → 6-Chloro-2,3-dihydro-1h-indole

HRID 1475298Notes

Reaction equation

HRID 1475298 reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]=[CH:7][NH:8]2)=[CH:4][CH:3]=1.C1COCC1.C(O)(C(F)(F)F)=O.[OH-].[Na+]>B>[Cl:1][C:2]1[CH:10]=[C:9]2[C:5]([CH2:6][CH2:7][NH:8]2)=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 8028TetrahydrofuranHCID 14798Sodium HydroxideHCID 871116-Chloroindole

Product 1

HCID 2585676-Chloro-2,3-dihydro-1h-indoleYield 86%

Reagents, catalysts & solvents 1

HCID 6331BoraneSolvent

Procedure

6-Chloroindole (1.0 g, 6.6 mmol) was dissolved in a solution of borane in THF (1 M, 9.83 mmol) at 0° C. and stirred for 30 min. TFA (9.83 mL) was added dropwise and the solution stirred at 0° C. for 30 min. 6 M aqueous NaOH was added until the solution was basic (pH 11). The aqueous solution was extracted with DCM (3×25 mL), dried over sodium sulfate, filtered and concentrated to give the title compound (864 mg, 86%) as a yellow oil. 1H NMR (Me-d3-OD): 6.99 (1H, d), 6.64-6.55 (2H, m), 3.50 (2H, t), 2.95 (2H, t).

Workup

  1. stirringthe solution stirred at 0° C. for 30 min
  2. extractionThe aqueous solution was extracted with DCM (3×25 mL)
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-dfd0637ca14c462ebf87bf1a7f81fca0
Source dataset
uspto-grants-2015_04
Patent number
US09018214B2

Reaction notes

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