反应详情

Methyl chloroformate (1.2 equiv) is added to a solution of a 2-(aminophenyl)alkanol (1 equiv) and DMAP (0.10 equiv) in pyridine (1 M) at 0° C. Additional pyridine is added as needed to keep the precipitates from accumulating. The solution is allowed to warm to room temperature and stirred for 2 hours. Sodium bisulfate (2N) and ethyl acetate are added, resulting in an aqueous layer and a first organic layer. The first organic layer is collected and the aqueous layer extracted with ethyl acetate. The organic layer from that extraction is combined with the first organic layer and that combined organic layer is washed sequentially with water and brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford a solid. To the solid is added potassium carbonate (2 equiv) in DMF (0.5-0.7 M) and that mixture is heated to 100° C. for 1-4 hours. The mixture is cooled and poured into ethyl acetate:water, resulting in a first organic layer and an aqueous layer. The first organic layer is collected and the aqueous layer is extracted with ethyl acetate. The organic layer from that extraction is combined with the collected first organic layer, and the combined organic layers are washed sequentially with water and brine, dried over magnesium sulfate, filtered, and concentrated to afford the 1,4-dihydro-2H-3,1-benzoxazin-2-one.

1. customprecipitates
2. additionSodium bisulfate (2N) and ethyl acetate are added
3. customresulting in an aqueous layer
4. customThe first organic layer is collected
5. extractionthe aqueous layer extracted with ethyl acetate
6. extractionThe organic layer from that extraction
7. washthat combined organic layer is washed sequentially with water and brine
8. dry with materialdried over magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customto afford a solid
12. temperaturethat mixture is heated to 100° C. for 1-4 hours
13. temperatureThe mixture is cooled
14. customThe first organic layer is collected
15. extractionthe aqueous layer is extracted with ethyl acetate
16. extractionThe organic layer from that extraction
17. washthe combined organic layers are washed sequentially with water and brine
18. dry with materialdried over magnesium sulfate
19. filtrationfiltered
20. concentrationconcentrated