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

Participants

Reaction Steps

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).

Provenance & Evidence