反应详情

To a scalemic mixture enriched in (1S,2R,4S)-2-ethyl-4-hydroxy-N-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)cyclopentanecarbo-hydrazide (9.06 g, 20.43 mmol) in DMF (40.9 mL) was added TBDMSCl (3.69 g, 24.51 mmol) and imidazole (3.48 g, 51.1 mmol). The reaction mixture was stirred at ambient temperature for about 4 h. The solvent was removed under reduced pressure. The residue was diluted with EtOAc (200 mL), filtered, and washed with EtOAc (20 mL). The filtrate was concd under reduced pressure. The residue was purified using silica gel chromatography eluting with 0-50% EtOAc in DCM to give a scalemic mixture enriched in (1S,2R,4S)-4-(tert-butyldimethylsilyloxy)-2-ethyl-N′-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)cyclopentanecarbohydrazide (11.37 g, 100%) as an orange solid: LC/MS (Table 1, Method b) Rt=3.14 min; MS m/z: 558 (M+H)+.

1. customThe solvent was removed under reduced pressure
2. additionThe residue was diluted with EtOAc (200 mL)
3. filtrationfiltered
4. washwashed with EtOAc (20 mL)
5. customThe residue was purified
6. washeluting with 0-50% EtOAc in DCM
7. customto give a scalemic mixture