反应详情

To a solution of 5-bromo-3-isopropoxy-2-methyl-pyridine 1-oxide (Stage 190.1.3, 2.054 mmol) in THF (13 ml) was added trifluoroacetic anhydride (10.27 mmol). The RM was stirred for 4 h at rt. The RM was evaporated to dryness. The residue was treated with saturated aqueous NaHCO3 (20 ml), stirred for 15 h at it and then extracted with EtOAc (2×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and evaporated. The residue was taken in DMA and purified by preparative HPLC. The fractions containing the product are basified with NaHCO3, concentrated and extracted with dichloromethane (2×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and evaporated to give a yellowish slowly crystallizing solid. (HPLC: tR 2.21 min (Method A); M+H=246, 248 MS-ES).

1. customThe RM was evaporated to dryness
2. additionThe residue was treated with saturated aqueous NaHCO3 (20 ml)
3. stirringstirred for 15 h at it
4. extractionextracted with EtOAc (2×)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customevaporated
9. custompurified by preparative HPLC
10. additionThe fractions containing the product
11. concentrationconcentrated
12. extractionextracted with dichloromethane (2×)
13. washThe combined organic layers were washed with brine
14. dry with materialdried over Na2SO4
15. filtrationfiltered
16. customevaporated
17. customto give a yellowish
18. customslowly crystallizing solid