反应详情

A solution of sodium chlorite (0.113 g) and sodium phosphate monobasic (0.168 g) in water (51 mL) was added to a suspension of tert-butyl 6-benzyloxycarbonylamino-3-(2-formylfuran-3-yl)-2-hydroxybenzoate (Intermediate 60, 0.438 g) and 2-methyl-2-butene (1.06 mL) in tert-butanol (25 mL) and acetonitrile (5 mL). The reaction mixture was stirred at room temperature. Further amounts of sodium chlorite (0.137 g) and sodium phosphate monobasic (0.180 g), in water (4 mL) were added and the reaction mixture was stirred at room temperature for 4.5 hours. The resultant mixture was basified to pH 10 with 1M sodium hydroxide solution and the mixture was concentrated in vacuo. Water (15 mL) was added and the mixture was extracted with ethyl acetate. The aqueous layer was acidified to pH 2 with 1M hydrochloric acid and extracted with ethyl acetate. The combined organic layers were dried (MgSO4), filtered and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a mixture of methanol and DCM, with a gradient of 0-15% to give 3-(4-benzyloxycarbonylamino-3-tert-butoxycarbonyl-2-hydroxyphenyl)-furan-2-carboxylic acid (0.385 g) as a yellow oil which solidified on standing.

1. stirringthe reaction mixture was stirred at room temperature for 4.5 hours
2. concentrationthe mixture was concentrated in vacuo
3. additionWater (15 mL) was added
4. extractionthe mixture was extracted with ethyl acetate
5. extractionextracted with ethyl acetate
6. dry with materialThe combined organic layers were dried (MgSO4)
7. filtrationfiltered
8. concentrationthe filtrate was concentrated in vacuo
9. customThe residue was purified by chromatography on silica
10. washeluting with a mixture of methanol and DCM, with a gradient of 0-15%