Ethyl Acetate → (R)-tert-butyl 3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamothioyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-tert-butyl 3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamoyl)-piperidine-1-carboxylate (7.58 g, 13.8 mmol) in 1,4-dioxane (130 mL) was added Lawesson's reagent (3.37 g, 8.32 mmol) and the reaction mixture was heated to about 60° C. for about 2 h then cooled to ambient temperature and concd under reduced pressure. The crude residue was dissolved with EtOAc (40 mL) and washed with saturated aqueous NaHCO3, (3×40 mL), brine (30 mL), dried over anhydrous MgSO4, filtered, and concd under reduced pressure. The crude material was purified by silica gel chromatography eluting with a gradient of 0-5% MeOH in DCM to afford (R)-tert-butyl 3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamothioyl)piperidine-1-carboxylate (5.6 g, 74%, UV purity 97%): LC/MS (Table 1, Method b) Rt=2.60 min; MS m/z: 530 (M+H)+.

Provenance & Evidence