Ethanol → (1-(3-Amino-5-fluoropyridin-4-yl)piperidin-4-yl)(4-methylpiperazin-1-yl)methanone hydrobromide

Participants

Reaction Steps

[1-(2-Bromo-5-fluoro-3-nitro-4-pyridyl)-4-piperidyl]-(4-methylpiperazin-1-yl)methanone 16 (20.24 g, 47.04 mmol) was dissolved/suspended in MeOH (389 mL)/EtOAc (78 mL) and Pd(OH)2 (1.651 g, 2.352 mmol) was added. The resulting mixture was degassed by vacuum/nitrogen cycles (×5) and the atmosphere was exchanged by vacuum/hydrogen cycles (×5). The reaction mixture was stirred vigorously under a hydrogen atmosphere (balloon) for 6 hrs. Additional Pd(OH)2 (4.95 g) was added and the reaction mixture was stirred overnight under hydrogen. The mixture was filtered through celite, washing through with methanol. The filtrate was concentrated in vacuo to leave an orange gum. Approx. 150 mL of ethanol was added and the mixture rotated on buchii for 10 mins, a yellow precipitate had formed during this time. The suspension was sonicated for 5 mins and the solid was then collected by filtration, washed with minimal ethanol and dried by suction for 1 h to afford product as a pale yellow solid. A second crop of product was obtained by concentrating the filtrate in vacuo. The residue was then slurried in minimal ethanol and sonicated for 5 mins then solid collected by filtration, dried by suction to leave second crop of product as a yellow solid. Both crops of product were combined to afford product as a yellow solid (15.8 g, 79%). MS (ES+) 322.2.

Provenance & Evidence