Pyridine → 6-(trifluoromethyl)-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Temperature

50 °C

To a suspension of 2-amino-5-(trifluoromethyl)benzoic acid (2 g, 9.75 mmol) in acetonitrile (10.0 ml) was added pyridine (2.31 g, 2.37 ml, 29.2 mmol) and a solution of triphosgene (1.74 g, 5.85 mmol) in acetonitrile (10.0 ml) at 50° C. The reaction mixture was stirred for 2 h at 50° C. Then additional triphosgene (579 mg, 1.95 mmol) was added and heating to 50° C. was continued overnight. The solvent was removed and water was added. The mixture was extracted with EtOAc and the combined extracts were washed with water and brine, dried with Na2SO4 and evaporated. The remaining residue was triturated in dichloromethane for 3 h. The solid was filtrated off and washed two times with dichloromethane to afford the crude title compound (1.53 g, 45%) as off-white solid. MS (ESI): 230.3 (M−H)+.

1. customat 50° C
2. temperatureheating to 50° C.
3. waitwas continued overnight
4. customThe solvent was removed
5. additionwater was added
6. extractionThe mixture was extracted with EtOAc
7. washthe combined extracts were washed with water and brine
8. dry with materialdried with Na2SO4
9. customevaporated
10. customThe remaining residue was triturated in dichloromethane for 3 h
11. filtrationThe solid was filtrated off
12. washwashed two times with dichloromethane

ORD record

ord-f823243c6ae9424aa2faca9faf826f16

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09199938B2