反应详情

To a solution of DMF (66 mmoles) in DCM there is added, dropwise, at 0° C., POCl3. After stirring for 5 minutes, a solution of the compound obtained in Step B (33 mmoles) in DCM (60 ml) is added dropwise. After stirring for 4 hours at 0° C. and for 30 minutes at reflux, an aqueous solution of sodium acetate (110 mmoles) is added. After a further 30 minutes at reflux, aqueous 2M sodium hydroxide solution is added at ambient temperature until the pH is alkaline (9-10). The solution is stirred for 2 hours at ambient temperature, and then 300 ml of DCM are added. After extracting with DCM, the organic phase is washed with water and with saturated aqueous NaCl solution, dried over sodium sulphate, filtered and evaporated to dryness. The residue obtained is purified by flash chromatography on silica gel (SiO2; gradient DCM/AcOEt) to yield the title product.

1. customat 0° C.
2. stirringAfter stirring for 4 hours at 0° C. and for 30 minutes
3. temperatureat reflux
4. temperatureAfter a further 30 minutes at reflux
5. stirringThe solution is stirred for 2 hours at ambient temperature
6. extractionAfter extracting with DCM
7. washthe organic phase is washed with water and with saturated aqueous NaCl solution
8. dry with materialdried over sodium sulphate
9. filtrationfiltered
10. customevaporated to dryness
11. customThe residue obtained
12. customis purified by flash chromatography on silica gel (SiO2; gradient DCM/AcOEt)