5-Chloroisatoic anhydride → Methyl 2-amino-5-chlorobenzoate

Participants

Reaction Steps

To a suspension of 6-chloro-1H-benzo[d][1,3]oxazine-2,4-dione (10 g, 50.61 mmol) in methanol (200 ml) was added DMAP (615 mg, 5.03 mmol) and the reaction mixture was heated to reflux for 3 h. The reaction mixture was cooled to RT and concentrated in vacuo. The residue was dissolved in EtOAc and washed with 0.1M HCl solution (3×), brine, dried over MgSO4, filtered and concentrated in vacuo to give the desired product (9.25 g, 97%) as a white solid which did not require further purification. 1H NMR (DMSO-d6, 300 MHz): δ 7.64 (d, J=2.5 Hz, 1H), 7.30 (dd, J=2.5 and 9.0 Hz, 1H), 6.82 (d, J=9.0 Hz, 1H), 6.78 (br s, 2H), 3.79 (s, 3H).

Provenance & Evidence