反应详情

To a solution of the compound obtained in Step B (0.113 mol) in a mixture of CH3CN (200 ml) and THF (200 ml) at −60° C. there is added, dropwise, ethyl (methylsulphanyl)-acetate (0.136 mol) under a nitrogen atmosphere. tBuOCl (0.136 mol) is added dropwise to the reaction mixture over 20 minutes, keeping the temperature between −60° C. and −55° C. After stiffing for one hour at −50° C., triethylamine (0.152 mol) is added dropwise. The reaction mixture is brought to 0° C. and then aqueous 3M HCl solution (580 ml) is added dropwise. After stiffing for 12 hours at ambient temperature, the organic phases are evaporated in vacuo and then the aqueous phase is extracted with DCM and the organic phases are combined. The organic phase obtained is washed with water and then with saturated aqueous NaCl solution. The organic phase is dried over sodium sulphate, filtered and evaporated to dryness. The product obtained is recrystallised from a mixture of ethyl ether/ethanol. The crystals obtained are filtered off, washed with ether and dried in vacuo at 40° C. to yield the title product, which is used directly in the next Step.

1. additionthere is added
2. customthe temperature between −60° C. and −55° C
3. customis brought to 0° C.
4. waitAfter stiffing for 12 hours at ambient temperature
5. customthe organic phases are evaporated in vacuo
6. extractionthe aqueous phase is extracted with DCM
7. customThe organic phase obtained
8. washis washed with water
9. dry with materialThe organic phase is dried over sodium sulphate
10. filtrationfiltered
11. customevaporated to dryness
12. customThe product obtained
13. customis recrystallised from a mixture of ethyl ether/ethanol
14. customThe crystals obtained
15. filtrationare filtered off
16. washwashed with ether
17. customdried in vacuo at 40° C.