Diisopropylethylamine → tert-butyl 4-methyl-3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamoyl)piperidine-1-carboxylate

Participants

Reaction Steps

To a slurry of (5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methanamine hydrochloride (29.6 g, 87.0 mmol, Step F), 1-(tert-butoxycarbonyl)-4-methylpiperidine-3-carboxylic acid (21.2 g, 87.0 mmol, Step G) and HATU (33.2 g, 87.0 mmol) in DCM (400 mL) was added DIEA (46.0 mL, 263 mmol). After stirring for about 18 h at ambient temperature, the reaction mixture was washed with aqueous saturated NaHCO3 (400 mL). The organic layer was separated, dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (330 g column) eluting with a gradient of 50-100% EtOAc in heptane to give tert-butyl 4-methyl-3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamoyl)piperidine-1-carboxylate (44 g, 95%) as a tan foam: LC/MS (Table 2, Method a) Rt=2.38 min; MS m/z: 528 (M+H)+.

Provenance & Evidence