Ethanol → Methyl 2-amino-1,3-benzoxazole-7-carboxylate

HRID 1845096Notes

Reaction equation

HRID 1845096 reaction equation
[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][CH:7]=[C:6]([NH2:10])[C:5]=1[OH:11].[N:13]#[C:14]Br.C(O)C>O>[CH3:1][O:2][C:3]([C:4]1[C:5]2[O:11][C:14]([NH2:13])=[N:10][C:6]=2[CH:7]=[CH:8][CH:9]=1)=[O:12]

Participants

5

Reactant 3

HCID 702EthanolHCID 10476Cyanogen BromideHCID 12782444Methyl 3-amino-2-hydroxybenzoate

Product 1

HCID 66940222Methyl 2-amino-1,3-benzoxazole-7-carboxylateYield 76%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 913 mg (5.46 mmol) 3-amino-2-hydroxy-benzoic acid methyl ester, 894 mg (8.19 mmol) of cyanogen bromide, 14.4 mL of ethanol and 1.6 mL of water was heated under reflux for 1 h. Ethanol was evaporated under reduced pressure and 20 mL of 2 N aq. Na2CO3 was added to the residue. The precipitated solid was filtered and washed with water. The remaining product was treated with methanol and the soluble filtrate containing the product was evaporated in vacuo to provide 797 mg (4.15 mmol, 76%) of 2-amino-benzooxazole-7-carboxylic acid methyl ester. LCMS: 193 (M+1)+.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 1 h
  3. customEthanol was evaporated under reduced pressure and 20 mL of 2 N aq. Na2CO3
  4. additionwas added to the residue
  5. filtrationThe precipitated solid was filtered
  6. washwashed with water
  7. additionThe remaining product was treated with methanol
  8. additionthe soluble filtrate containing the product
  9. customwas evaporated in vacuo

Sources & evidence

ORD record
ord-fef5931b52984a8fbf24b780769d2774
Source dataset
uspto-grants-2015_02
Patent number
US08946259B2

Reaction notes

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