Methyl iodide → 4-Methoxybenzo(d)oxazole

HRID 2230428Notes

Reaction equation

HRID 2230428 reaction equation
[OH:1][C:2]1[C:7]2[N:8]=[CH:9][O:10][C:6]=2[CH:5]=[CH:4][CH:3]=1.[C:11]([O-])([O-])=O.[K+].[K+].IC>CC(C)=O>[CH3:11][O:1][C:2]1[C:7]2[N:8]=[CH:9][O:10][C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 137206971,3-Benzoxazol-4-ol

Product 1

HCID 225009354-Methoxybenzo(d)oxazoleYield 91%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a suspension of 4-hydroxybenzoxazole (2.00 g, 14.8 mmol) (Musser et al., J. Med. Chem., 30, pp. 62-67 (1987)) in acetone (80.0 ml) was added dried K2CO3 (2.25 g, 16.3 mmol) followed by iodomethane (1.38 ml, 22.2 mmol). The reaction was heated under reflux under N2 for 4.5 h, then filtered and reduced in vacuo to afford the crude product. The resulting residue was purified by flash chromatography (25:75 ethyl acetate/hexane) to give 2.0 g (91%) of the title compound as a white crystalline solid: m.p. 72-74° C.; IR (KBr) 3089, 1619, 1610, 1503, 1496, 1322, 1275, 1090, 1071, 780, 741; 1H NMR (CDCl3) δ8.02 (1H, s), 7.32 (1H, t, J=8.0), 7.18 (1H, d, J=8.0), 6.81 (1H, d, J=8.0), 4.04 (3H, s). Anal. Calcd. for C8H7NO2: C, 64.42; H, 4.73; N, 9.39. Found: C, 64.40; H, 4.84; N, 9.31; m/z (EI) 149 (M++1, 100%).

Workup

  1. temperatureThe reaction was heated
  2. temperatureunder reflux under N2 for 4.5 h
  3. filtrationfiltered
  4. customto afford the crude product
  5. customThe resulting residue was purified by flash chromatography (25:75 ethyl acetate/hexane)

Sources & evidence

ORD record
ord-7deddde07b0c432a85a738f861b29b6a
Source dataset
uspto-grants-2002_07
Patent number
US06423840B1

Reaction notes

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