Dichloromethane → 3-Chloroisatoic anhydride

Temperature

50 °C

To a stirred solution of 2-amino-5-methoxy benzoic acid (9 g, 0.054 mmol) in acetonitrile (60 mL, 1 M), was added pyridine (8.7 mL, 0.108 mmol, 2 equiv), and triphosgene (15.9 g, 0.054 mmol, 1 equiv) in dichloromethane (85 mL, 0.7 M). The orange reaction solution was heated at 50° C. for two hours then cooled to room temperature. The solution was diluted with water (50 mL), and the organic and aqueous layers were separated. The aqueous layer was washed with dichloromethane (3×50 mL), and the combined organic layers were washed once with brine (50 mL), and dried over magnesium sulfate. The solvent was removed in vacuo leaving a yellow solid. The solid was titrated with hexanes to yield 8-chloro-1H-benzo[d][1,3]oxazine-2,4-dione (8.3 g, 80%) as a white solid.

1. temperaturethen cooled to room temperature
2. customthe organic and aqueous layers were separated
3. washThe aqueous layer was washed with dichloromethane (3×50 mL)
4. washthe combined organic layers were washed once with brine (50 mL)
5. dry with materialdried over magnesium sulfate
6. customThe solvent was removed in vacuo
7. customleaving a yellow solid

ORD record

ord-e18e2b03a34449299dee0648922c0691

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08815845B2