Ethyl orthopropionate → 2-ethyl-5-nitro-1,3-benzoxazole

HRID 2289486Notes

Reaction equation

HRID 2289486 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][C:3]=1[OH:11].[C:12](OCC)(OCC)(OCC)[CH2:13][CH3:14]>C(O)C.C1(C)C=CC(S(O)(=O)=O)=CC=1>[CH2:13]([C:14]1[O:11][C:3]2[CH:4]=[CH:5][C:6]([N+:8]([O-:10])=[O:9])=[CH:7][C:2]=2[N:1]=1)[CH3:12]

Participants

5

Reactant 2

HCID 66995Ethyl orthopropionateHCID 36133892-Amino-4-Nitrophenol

Product 1

HCID 27635762-ethyl-5-nitro-1,3-benzoxazoleYield 84.6%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 702EthanolSolvent

Procedure

A solution of 2-amino-4-nitrophenol (2.00 g, 12.98 mmol) and triethyl orthopropionate (4.57 g, 25.95 mmol) in anhydrous ethanol (15 ml) was treated with p-toluenesulphonic acid (20 mg) and the resulting mixture refluxed for 3 h. On cooling to room temperature a precipitate formed which was filtered off and dried to afford the title compound (2.11 g) as a beige solid m.p. 88-90°. δH (CDCl3) 1.48 (3H, t, J 7.6 Hz), 3.02 (2H, q, J 7.6 Hz), 7.57 (1H, d, J 9.0 Hz), 8.27 (1H, dd, J 2.3, 9.0 Hz) and 8.55 (1H, d, J 2.3 Hz).

Workup

  1. temperaturethe resulting mixture refluxed for 3 h
  2. customformed which
  3. filtrationwas filtered off
  4. customdried

Sources & evidence

ORD record
ord-dc21028f9502440f905f03d019cb038a
Source dataset
uspto-grants-2000_07
Patent number
US06093716

Reaction notes

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