Acetyl chloride → 2-Methyl-benzooxazole-4-carboxylic acid ethyl ester

HRID 560309Notes

Reaction equation

HRID 560309 reaction equation
[CH2:1]([O:3][C:4](=[O:13])[C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([OH:11])[C:6]=1[NH2:12])[CH3:2].[C:14](Cl)(=O)[CH3:15].CCN(CC)CC.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C1(C)C(C)=CC=CC=1.CCOC(C)=O>[CH2:1]([O:3][C:4]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]2[O:11][C:14]([CH3:15])=[N:12][C:6]=12)=[O:13])[CH3:2]

Participants

7

Reactant 4

HCID 6367Acetyl chlorideHCID 8471TriethylamineHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 14167647Ethyl 2-amino-3-hydroxybenzoate

Product 1

HCID 593168402-Methyl-benzooxazole-4-carboxylic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 7237O-XyleneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A mixture of 2-amino-3-hydroxy-benzoic acid ethyl ester (5.52 mmol; J. Reisch, G. M. K. B. Gunaherath Monatshefte für Chemie, 1988, 119, 1169-1178), acetyl chloride (6.07 mmol), NEt3 (6.07 mmol) and pyridinium p-toluenesulfonate (1.47 mmol) in xylene (60 mL) is heated at reflux for 16 h, cooled to RT, diluted with EtOAc and washed with water. The organic layer is dried over MgSO4 and concentrated in vacuo to give a crude product which is purified by FC (gradient: heptane to heptane/EtOAc 6/4). LC-MS: tR=0.81 min; [M+H]+=206.0.

Workup

  1. temperatureis heated
  2. temperatureat reflux for 16 h
  3. washwashed with water
  4. dry with materialThe organic layer is dried over MgSO4
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-cbc19d47ea45452a908bf20c817ba802
Source dataset
uspto-grants-2011_11
Patent number
US08063099B2

Reaction notes

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