Sodium Hydroxide → 6-Chloro-2,3-dihydro-1h-indole

HRID 1372426Notes

Reaction equation

HRID 1372426 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.C([BH3-])#N.[Na+].[OH-].[Na+]>C(O)(=O)C.O>[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 3

HCID 14798Sodium HydroxideHCID 871116-ChloroindoleHCID 5003444Sodium cyanoborohydride

Product 1

HCID 2585676-Chloro-2,3-dihydro-1h-indoleYield 98.6%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

6-Chloroindole (1 g, 6.6 mmol) in glacial acetic acid (10 mL) was treated with sodium cyanoborohydride (829 mg, 13.2 mmol) portionwise at room temperature with stirring. After 1 hour, the reaction was diluted with water (25 mL) and basified with 40% sodium hydroxide with cooling. The mixture was then extracted with dichloromethane (3×50 mL), dried and concentrated to give 1 g of 6-chloroindoline. It was used in the next step without further purification. 1HNMR (300 MHz, dimethylsulfoxide-d6) δ 6.95 (d, 1H), 6.46 (dd, 1H), 6.43 (d, 1H), 5.74 (br s, 1H, NH), 3.42 (t, 2H, CH2), 2.85 (t, 2H, CH2). MS m/z 349 [M+1].

Workup

  1. temperaturewith cooling
  2. extractionThe mixture was then extracted with dichloromethane (3×50 mL)
  3. customdried
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-7733c2c6deb94b5a9eefadd53a70dac1
Source dataset
uspto-grants-2007_01
Patent number
US07157577B2

Reaction notes

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