Cyclopentyl chloroformate → (R)-cyclopentyl 3-(6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazin-1-yl)piperidine-1-carboxylate

To a solution of (R)-1-(piperidin-3-yl)-6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazine hydrochloride (0.06 g, 0.19 mmol) in THF (1 mL) was added TEA (0.08 mL, 0.57 mmol) and the reaction was stirred at ambient temperature for about 10 min. To the reaction mixture was added cyclopentyl chloroformate (0.02 mL, 0.15 mmol, Waterstone) and the mixture was stirred at about 45° C. for about 18 h. The reaction mixture was cooled to ambient temperature and concd under reduced pressure. The crude material was dissolved in DCM (5 mL) and washed with water (5 mL). The organic layer was separated and the aqueous layer was back extracted with DCM (2 mL). The combined organic extracts were dried over anhydrous MgSO4, filtered, and concd under reduced pressure. The material was purified by silica gel chromatography eluting with a gradient of 0-5% MeOH in DCM to afford (R)-cyclopentyl 3-(6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazin-1-yl)piperidine-1-carboxylate (0.015 g, 21%): LC/MS (Table 1, Method b) Rt=1.87 min; MS m/z: 354 (M+H)+.

1. stirringthe mixture was stirred at about 45° C. for about 18 h
2. temperatureThe reaction mixture was cooled to ambient temperature
3. washwashed with water (5 mL)
4. customThe organic layer was separated
5. extractionthe aqueous layer was back extracted with DCM (2 mL)
6. dry with materialThe combined organic extracts were dried over anhydrous MgSO4
7. filtrationfiltered
8. customThe material was purified by silica gel chromatography
9. washeluting with a gradient of 0-5% MeOH in DCM

ORD record

ord-f63576e313fa4cfe9d0f68337d80a763

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08426411B2