反应详情

温度

0 °C

Into a 500 mL 3-necked round bottom flask was placed a solution of 7-amino-2H-benzo[b][1,4]oxazin-3(4H)-one (5 g, 28.96 mmol) in CH3CN (200 mL). To the above was added acetic acid (24.9 g) dropwise with stirring, while cooling to a temperature of 0° C. To the above was added HCl (16.2 g) dropwise with stirring, while cooling to a temperature of 0° C. This was followed by the addition of a solution of NaNO2 (2.52 g, 36.52 mmol) in H2O (2 mL), which was added dropwise with stirring, while cooling to a temperature of 0° C. The resulting solution was allowed to react, with stirring, for 30 minutes while the temperature was maintained at 0-5° C. in a bath of H2O/ice. This was followed by and maintained with an atmosphere of sulfur dioxide, the resulting solution was allowed to react, with stirring, for an additional 2 hours while the temperature was maintained at 0-5° C. in a bath of H2O/ice. To the mixture was added CuCl2.2H2O (5.11 g, 29.97 mmol), while cooling to a temperature of 0-5° C. The resulting solution was allowed to react, with stirring, maintained with an atmosphere of sulfur dioxide for an additional 2 hours while the temperature was maintained at 0-5° C. in a bath of H2O/ice. The resulting solution was allowed to react, with stirring, overnight while the temperature was maintained at room temperature. The reaction progress was monitored by TLC (petroleum ether/ethyl acetate=1:1). The reaction mixture was then quenched by the adding 200 mL of H2O/ice. The resulting solution was extracted one time with 500 mL of ethyl acetate and the organic layers combined. Then the mixture was washed 3 times with 200 mL of brine. The mixture was dried over MgSO4 and concentrated by evaporation under vacuum using a rotary evaporator. The residue was dissolved in 100 mL of CH2Cl2. A filtration was performed. The filtrate was concentrated by evaporation under vacuum using a rotary evaporator. This resulted in 0.9 g (11%) of 3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonyl chloride as a yellow solid. 1HNMR (400 MHz, CDCl3) δ 4.73 (s, 2H), 7.00 (m, 1H), 7.28 (d, 1H), 7.71 (d, 1H), 8.27 (s, 1H).

1. customInto a 500 mL 3-necked round bottom flask was placed
2. stirringwith stirring
3. temperaturewhile cooling to a temperature of 0° C
4. additionwas added dropwise
5. stirringwith stirring
6. temperaturewhile cooling to a temperature of 0° C
7. customto react
8. stirringwith stirring, for 30 minutes while the temperature
9. customto react
10. stirringwith stirring, for an additional 2 hours while the temperature
11. temperaturewhile cooling to a temperature of 0-5° C
12. customto react
13. stirringwith stirring
14. customto react
15. stirringwith stirring, overnight while the temperature
16. temperaturewas maintained at room temperature
17. customThe reaction mixture was then quenched by the adding 200 mL of H2O/ice
18. extractionThe resulting solution was extracted one time with 500 mL of ethyl acetate
19. washThen the mixture was washed 3 times with 200 mL of brine
20. dry with materialThe mixture was dried over MgSO4
21. concentrationconcentrated by evaporation under vacuum
22. customa rotary evaporator
23. dissolutionThe residue was dissolved in 100 mL of CH2Cl2
24. filtrationA filtration
25. concentrationThe filtrate was concentrated by evaporation under vacuum
26. customa rotary evaporator
27. customThis resulted in 0.9 g (11%) of 3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonyl chloride as a yellow solid