Imidazole → 4-(tert-butyldimethylsilyloxy)-2-ethyl-N'-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)cyclopentanecarbohydrazide

Participants

Reaction Steps

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)+.

Provenance & Evidence