Benzoyl chloride → 6-bromo-2-phenyl-4H-benzo[d][1,3]oxazin-4-one
Reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:8]([Br:11])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[C:12](Cl)(=O)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>>[Br:11][C:8]1[CH:9]=[CH:10][C:2]2[N:1]=[C:12]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[O:5][C:4](=[O:6])[C:3]=2[CH:7]=1Participants
3
Procedure
The 2-amino-5-bromobenzoic acid (5 g, 23.1 mmol) was treated with benzoyl chloride (237 mL, 2.04 mol) at 140° C. for 3 h. After the reaction mixture was cooled to rt, the crystals that formed were collected by filtration and were washed with hexanes to provide 64 as light brown needles (6.8 g, 97%): 1H NMR (CDCl3) δ 7.51-7.2 (m, 4H), 7.9 (dd, 1H, J=2.3, 8.6 Hz), 8.30-8.33 (m, 2H), 8.8 (d, 1H, J=2.2 Hz); 13C NMR (CDCl3) δ 158.19, 157.35, 145.75, 139.58, 132.82, 130.97, 129.77, 128.82, 128.73, 128.29, 121.37, 118.27; MS (EI) m/e (relative intensity) 303 (M+, 36), 301 (M+, 36), 259 (14), 257 (14), 226 (6), 224 (6), 178 (9), 170 (9), 168 (9), 151 (4), 105 (100).
Workup
- customthe crystals that formed