2-Aminophenol → 2H-1,4-benzoxazin-3(4H)-one

Temperature

0 °C

Into a 100 mL round bottom flask was placed a solution of 2-aminophenol (5.45 g, 49.98 mmol) in CHCl3 (30 mL). To this was added TEBA (11.4 g, 50.00 mmol). To the mixture was added NaHCO3 (16.8 g, 200.00 mmol). This was followed by the addition of a solution of 2-chloroacetyl chloride (8.16 g, 72.21 mmol) in CHCl3 (5 mL), which was added dropwise with stirring, while cooling to a temperature of 0° C. over a time period of 20 minutes. The resulting solution was allowed to react, with stirring, for 1 hour while the temperature was maintained at 0-5° C. The resulting solution was allowed to react, with stirring, overnight while the temperature was maintained at 55° C. The mixture was concentrated by evaporation under vacuum using a rotary evaporator. The product was precipitated by the addition of H2O. A filtration was performed. The filter cake was washed 2 times with 50 mL of H2O. The final product was purified by recrystallization from ethanol. This resulted in 4.5 g (60%) of 2H-benzo[b][1,4]oxazin-3(4H)-one as a white solid.

1. customInto a 100 mL round bottom flask was placed
2. additionwas added dropwise
3. customto react
4. stirringwith stirring, for 1 hour while the temperature
5. temperaturewas maintained at 0-5° C
6. customto react
7. stirringwith stirring, overnight while the temperature
8. temperaturewas maintained at 55° C
9. concentrationThe mixture was concentrated by evaporation under vacuum
10. customa rotary evaporator
11. customThe product was precipitated by the addition of H2O
12. filtrationA filtration
13. washThe filter cake was washed 2 times with 50 mL of H2O
14. customThe final product was purified by recrystallization from ethanol
15. customThis resulted in 4.5 g (60%) of 2H-benzo[b][1,4]oxazin-3(4H)-one as a white solid

ORD record

ord-de2fdebe5f564ad6a8638a3066189710

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07696229B2