Methyl iodide → 5-{[tert-butyl(dimethyl)silyl]oxy}-3-methyl-1,3-benzoxazol-2(3H)-one

HRID 1965259Notes

Reaction equation

HRID 1965259 reaction equation
[Si:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]2[O:16][C:15](=[O:17])[NH:14][C:13]=2[CH:18]=1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[H-].[Na+].I[CH3:22]>CN(C)C=O.O.C(OCC)(=O)C>[Si:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]2[O:16][C:15](=[O:17])[N:14]([CH3:22])[C:13]=2[CH:18]=1)([C:4]([CH3:7])([CH3:5])[CH3:6])([CH3:3])[CH3:2]

Participants

7

Reactant 3

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 666312795-{[tert-butyl(dimethyl)silyl]oxy}-1,3-benzoxazol-2(3H)-one

Product 1

HCID 673568635-{[tert-butyl(dimethyl)silyl]oxy}-3-methyl-1,3-benzoxazol-2(3H)-oneYield 83.5%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled (0° C.) solution of 5-{[tert-butyl(dimethyl)silyl]oxy}-1,3-benzoxazol-2(3H)-one (1.45 g, 5.4 mmol) in anhydrous N,N-dimethylformamide (10 mL) was added sodium hydride (0.26 g, 60% dispersion in mineral oil, 6.6 mmol). The reaction mixture was stirred at 0° C. for 15 min followed by the addition of iodomethane (1.0 mL, 16 mmol). The reaction mixture was stirred at ambient temperature for 16 h and diluted with water (20 mL) and ethyl acetate (20 mL). The phases were separated and the aqueous phase was extracted with ethyl acetate (2×20 mL). The combined organic solution was washed with water (5×20 mL) and brine (2×20 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by column chromatography with ethyl acetate in hexanes (0 to 25% gradient) to afford 5-{[tert-butyl(dimethyl)silyl]oxy}-3-methyl-1,3-benzoxazol-2(3H)-one (1.26 g, 83%) as a pale yellow solid: 1H NMR (300 MHz, CDCl3) δ7.02 (d, J=8.6 Hz, 1H), 6.55 (dd, J=8.6, 2.4 Hz, 1H), 6.44 (d, J=2.4 Hz, 1H), 3.35 (s, 3H), 0.99 (s, 9H), 0.20 (s, 6H).

Workup

  1. stirringThe reaction mixture was stirred at ambient temperature for 16 h
  2. customThe phases were separated
  3. extractionthe aqueous phase was extracted with ethyl acetate (2×20 mL)
  4. washThe combined organic solution was washed with water (5×20 mL) and brine (2×20 mL)
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe crude product was purified by column chromatography with ethyl acetate in hexanes (0 to 25% gradient)

Sources & evidence

ORD record
ord-0191878c805048c493bdd66c9a96ba9c
Source dataset
uspto-grants-2013_04
Patent number
US08415370B2

Reaction notes

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