2,3-Diaminopyridine → tert-Butyl 4-[(2-aminopyridin-3-yl)amino]piperidine-1-carboxylate

Participants

Reaction Steps

tert-Butyl 4-oxopiperidine-1-carboxylate (9.59 g, 48.1 mmol) and pyridine-2,3-diamine (5.0 g, 45.8 mmol) were combined and dissolved in 1,2-dichloroethane (75 ml). Sodium triacetoxyborohydride (14.5 g, 68.4 mmol) was added to the mixture. Reaction stirred at room temperature for 7 hours. Additional sodium triacetoxyborohydride (3.60 g, 16.99 mmol) was added to the mixture. Reaction stirred at room temperature for 18 hours. Reaction was quenched with 1N sodium hydroxide. Material was extracted twice with dichloromethane and the aqueous phase was discarded. Material was washed successively with 1N sodium hydroxide, water, and brine and the aqueous phases were discarded. Organics were dried MgSO4, filtered and then concentrated to dryness. Silica gel chromatography eluting methanol-dichloromethane afforded the title compound as tan foam in 48% yield. MS (M−H)−=291.2.

Provenance & Evidence