2-Propanamidobenzoic acid → 2-Ethyl-benzo[d][1,3]oxazin-4-one

HRID 238193Notes

Reaction equation

HRID 238193 reaction equation
[C:1]([NH:5][C:6]1[CH:14]=[CH:13][CH:12]=[CH:11][C:7]=1[C:8]([OH:10])=[O:9])(=O)[CH2:2][CH3:3]>C(OC(=O)C)(=O)C>[CH2:2]([C:1]1[O:9][C:8](=[O:10])[C:7]2[CH:11]=[CH:12][CH:13]=[CH:14][C:6]=2[N:5]=1)[CH3:3]

Participants

3

Reactant 1

HCID 32646742-Propanamidobenzoic acid

Product 1

HCID 9285262-Ethyl-benzo[d][1,3]oxazin-4-oneYield 93.6%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

A mixture of 2-Propionylamino-benzoic acid (1.0 g, 5 mmol) and acetic anhydride (10 mL) were heated to reflux for 3 hours until TLC indicated that no more starting material remained. The remaining acetic anhydride was removed in vacuo. Toluene (2 mL) was added and then removed in vacuo. This was repeated 2 more times to try and remove final traces of acetic anhydride. The product was obtained as a pale yellow solid (820 mg, 90%). 1H NMR (CDCl3) δ 1.37 (t, 3H, J=7.6 Hz), 2.73 (q, 2H, J=7.6 Hz), 7.50 (t, 1H, J=7.6 Hz), 7.57 (d, 1H, J=80 Hz), 7.79 (t, 1H, J=7.7 Hz), 8.19 (d, 1H, J=8.1 Hz).

Workup

  1. temperaturewere heated
  2. temperatureto reflux for 3 hours until TLC
  3. customThe remaining acetic anhydride was removed in vacuo
  4. additionToluene (2 mL) was added
  5. customremoved in vacuo
  6. customremove final traces of acetic anhydride

Sources & evidence

ORD record
ord-415bc08e52ff438484bb086fa7ce7b1d
Source dataset
uspto-grants-2014_02
Patent number
US08642609B2

Reaction notes

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