Ethyl Acetate → tert-butyl 4-methyl-3-(6-tosyl-6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazin-1-yl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-methyl-3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamoyl)piperidine-1-carboxylate (44 g, 83 mmol, Example #13, Step H) in 1,4-dioxane (500 mL) was added Lawesson's reagent (20.2 g, 50.0 mmol). The reaction was heated at about 80° C. for about 1 h. The reaction was allowed to cool to ambient temperature followed by the addition of diacetoxymercury (26.6 g, 83.0 mmol). After about 1 h, additional diacetoxymercury (13.3 g, 42.0 mmol) was added. After about 15 min, the reaction was poured into stirred EtOAc (2 L). After about 15 min the reaction was filtered through Celite® and the filtrate was concentrated under reduced pressure. The resulting residue was triturated with EtOAc (500 mL) and filtered. The filtrate was concentrated under reduced pressure and purified by silica gel chromatography (330 g column) eluting with a gradient of 10-50% EtOAc in heptane to provide tert-butyl 4-methyl-3-(6-tosyl-6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazin-1-yl)piperidine-1-carboxylate (19 g, 44%) as a white solid: LC/MS (Table 2, Method a) Rt=2.57 min; MS m/z: 510 (M+H)+.

Provenance & Evidence