Dimethyl Sulfate → N-Methyloxindole

HRID 383869Notes

Reaction equation

HRID 383869 reaction equation
[H-].[Na+].[NH:3]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[CH2:5][C:4]1=[O:12].S(OC)(O[CH3:17])(=O)=O>C1(C)C(C)=CC=CC=1>[CH3:17][N:3]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[CH2:5][C:4]1=[O:12]

Participants

5

Reactant 3

HCID 6497Dimethyl SulfateHCID 24758Sodium hydrideHCID 321710Oxindole

Product 1

HCID 6096N-MethyloxindoleYield 67.3%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

A stirred mixture of sodium hydride (60%, 31 g, 0.79 mol) in dry xylene (500 mL), under a nitrogen atmosphere, was heated to reflux for 30 min. 1,3-Dihydro-indol-2-one 16a (100 g, 0.75 mol) was then slowly added via an addition funnel and stirred at reflux for 1.5 hours. Dimethyl sulfate (104 g, 0.83 mol) was added drop-wise, whereupon the resulting homogeneous solution was refluxed for an additional 2 hours. After cooling to room temperature, the reaction mixture was washed with water, dried over Na2SO4, and concentrated under reduced pressure to afford 1-methyl-1,3-dihydro-indol-2-one 16b (74 g, 67.3%). 1H NMR (300 MHz, CDCl3) δ 7.23-7.31 (m, 2H), 7.04 (t, J=7.5 Hz, 1H), 6.82 (d, J=7.8 Hz, 1H), 3.52 (s, 2H), 3.21 (s, 3H).

Workup

  1. temperatureunder a nitrogen atmosphere, was heated
  2. temperatureto reflux for 30 min
  3. temperatureat reflux for 1.5 hours
  4. temperaturewhereupon the resulting homogeneous solution was refluxed for an additional 2 hours
  5. washthe reaction mixture was washed with water
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-a58b6cf8d3ee42a0b50d2e329b9ba7a8
Source dataset
uspto-grants-2013_02
Patent number
US08367691B2

Reaction notes

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