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

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Reaction Steps

To a slurry of (5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methanamine hydrochloride (34.0 g, 100 mmol, Example #5, Step C), (3R,4R)-1-(tert-butoxycarbonyl)-4-methylpiperidine-3-carboxylic acid (24.43 g, 100 mmol) and HATU (38.2 g, 100 mmol) in DCM (700 mL) was added DIEA (52.6 mL, 301 mmol). The reaction was stirred at ambient temperature for about 45 min. The reaction was washed with saturated aqueous NaHCO3 (300 mL). The organic layer was separated, dried over anhydrous Na2SO4, filtered then concd in vacuo. The resulting residue was purified by chromatography on silica gel (330 g) using 33-100% EtOAc in heptane to give (3R,4R)-tert-butyl-4-methyl-3-((5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)methylcarbamoyl)piperidine-1-carboxylate (53 g, 100%) as a pale-yellow foam: LC/MS (Table 1, Method b) Rt=2.40 min; MS m/z: 528 (M+H)+.

Provenance & Evidence