Chloroacetyl chloride → 6,7-Difluoro-4H-benzo[1,4]oxazin-3-one

Participants

Reaction Steps

A crude of 2-amino-4,5-diflourophenol (2.67 g, 18.4 mmol), 2-chloroacetyl chloride (2.28 g, 20 mmol) and K2CO3 (5.34 g, 38.6 mmol) were mixed according to GP1. Purified by column chromatography (SiO2; heptanes/EtOAc 4:1 to 1:1) to give the title compound (2.17 g, 64%). Rf=0.43 (heptanes/EtOAc 1:1); Mp=214.5-219.2° C.; 1H NMR (CD3OD) d 6.90 (dd, J=11.4 Hz, J=7.2 Hz, 1H), 6.80 (dd, J=11.0 Hz, J=7.7 Hz, 1H), 4.56 (s, 2H); 13C NMR (CD3OD) d 167.0, 147.0 (dd, J=243.5 Hz, J=13.8 Hz), 146.9 (dd, J=240.0 Hz, J=13.8 Hz), 141.2 (dd, J=9.8 Hz, J=3.0 Hz), 124.8 (dd, J=8.7 Hz, J=3.0 Hz), 106.9 (dd, J=22.0 Hz, J=6.9 Hz), 105.5 (dd, J=23.1 Hz, J=4.6 Hz), 68.1 (t, J=6.5 Hz).

Provenance & Evidence