2-Aminophenol → 2-Ethyl-4-nitro-1,3-benzoxazole

HRID 1727238Notes

Reaction equation

HRID 1727238 reaction equation
[NH2:1][C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][CH:5]=[CH:4][C:3]=1[OH:11].[C:12](OCC)(OCC)(OCC)[CH2:13][CH3:14].C1(C)C=CC(S(O)(=O)=O)=CC=1.NC1C=CC=CC=1O>C1(C)C=CC=CC=1>[CH2:13]([C:14]1[O:11][C:3]2[CH:4]=[CH:5][CH:6]=[C:7]([N+:8]([O-:10])=[O:9])[C:2]=2[N:1]=1)[CH3:12]

Participants

6

Reactant 4

HCID 58012-AminophenolHCID 6101p-Toluenesulfonic acidHCID 66995Ethyl orthopropionateHCID 41154952-Amino-3-Nitrophenol

Product 1

HCID 120715882-Ethyl-4-nitro-1,3-benzoxazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 2-amino-3-nitrophenol (1 eq.), triethyl orthopropionate (2 eq.) and p-toluene sulphonic acid (in a catalytic quantity) is stirred at 110° C. until disappearance of the aminophenol is verified by thin layer chromatography (2 hours). After cooling down, the reaction mixture is taken up in toluene followed by evaporating under vacuum then treating with isopropanol. The resulting precipitate is collected by filtration, followed by washing with isopropanol and isopentane, then drying under reduced pressure in order to produce a violet-brown solid.

Workup

  1. customis verified by thin layer chromatography (2 hours)
  2. temperatureAfter cooling down
  3. customby evaporating under vacuum
  4. additionthen treating with isopropanol
  5. filtrationThe resulting precipitate is collected by filtration
  6. washby washing with isopropanol and isopentane
  7. customdrying under reduced pressure in order
  8. customto produce a violet-brown solid

Sources & evidence

ORD record
ord-aa3e2bc8284a4243966e35021fe21df5
Source dataset
uspto-grants-2009_02
Patent number
US07495021B2

Reaction notes

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