反应详情

A mixture of 3-bromo-4-chloro-N-(2-hydroxy-6-methyl-phenyl)-benzamide (11.3 g, 33.2 mmol), t-butyl 4-bromobutyrate (8.2 g, 36.6 mmol) and K2CO3 (9.2 g, 66.5 mmol) was heated in DMF (100 mL) at 60° C. for 14 hrs. The mixture was then concentrated to remove DMF and partitioned between ethyl acetate and water. The organic layer was separated and washed with water and brine, dried over MgSO4, then purified by silica gel column chromatography eluting with ethyl acetate/hexane (1/4) to yield a red solid, which was further washed with ether to produce a white powder as 4-[2-(3-bromo-4-chloro-benzoylamino)-3-methyl-phenoxy]-butyric acid tert-butyl ester (10.2 g). MS [M-(t-Bu)+H]+: 425.8/427.8; tR=2.79 min. (method 1)

1. concentrationThe mixture was then concentrated
2. customto remove DMF
3. custompartitioned between ethyl acetate and water
4. customThe organic layer was separated
5. washwashed with water and brine
6. dry with materialdried over MgSO4
7. custompurified by silica gel column chromatography
8. washeluting with ethyl acetate/hexane (1/4)
9. customto yield a red solid, which
10. washwas further washed with ether