Water → 6,7-Dimethyl-5-methoxy-1,2-dihydro-1h-indole

HRID 1743398Notes

Reaction equation

HRID 1743398 reaction equation
[CH3:1][C:2]1[C:10]([CH3:11])=[C:9]2[C:5]([CH2:6][C:7](=O)[NH:8]2)=[CH:4][C:3]=1[O:13][CH3:14].O>C1COCC1>[CH3:1][C:2]1[C:10]([CH3:11])=[C:9]2[C:5]([CH2:6][CH2:7][NH:8]2)=[CH:4][C:3]=1[O:13][CH3:14]

Participants

4

Reactant 2

HCID 962WaterHCID 222380866,7-Dimethyl-5-methoxy-1,3-dihydro-2H-indole-2-one

Product 1

HCID 222380716,7-Dimethyl-5-methoxy-1,2-dihydro-1h-indoleYield 66%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of 6,7-dimethyl-5-methoxy-1,3-dihydro-2H-indole-2-one (17.5 g, 91.5 mmol) in THF (500 mL) was added dropwise 1M-borane THF complex salt (306 mmol) at 0° C., and the mixture was stirred at 60° C. 3 hours. After ice-cooling, the mixture was added dropwise to water (100 mL). THF was distilled off under reduced pressure, concentrated hydrochloric acid (100 mL) was added, and the mixture was stirred under reflux for 2 hours. After neutralizing with 12N sodium hydroxide under ice-cooling, the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over sodium sulfate, and purified by small amount silica gel column chromatography (ethyl acetate). The solvent was distilled off under reduced pressure, followed by recrystallization from hexane, to obtain 8.18 g of the title compound.

Workup

  1. custom3 hours
  2. temperatureAfter ice-cooling
  3. distillationTHF was distilled off under reduced pressure, concentrated hydrochloric acid (100 mL)
  4. additionwas added
  5. stirringthe mixture was stirred
  6. temperatureunder reflux for 2 hours
  7. temperaturecooling
  8. extractionthe mixture was extracted with ethyl acetate
  9. washThe organic layer was washed with saturated brine
  10. dry with materialdried over sodium sulfate
  11. custompurified by small amount silica gel column chromatography (ethyl acetate)
  12. distillationThe solvent was distilled off under reduced pressure
  13. customfollowed by recrystallization from hexane

Sources & evidence

ORD record
ord-f231fb87325e4d3f9cf62be08a9c2d3b
Source dataset
uspto-grants-2006_03
Patent number
US07008940B1

Reaction notes

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