Synthesis
General Steps:
Step 1: Add 4-amino-3-bromopyridine (1.0 eq.) and BrettPhos G1 pre-catalyst (6 mol%) to a Schlenk vial fitted with a magnetic stir bar under argon protection. The reaction vial was sealed with a PTFE screw cap and three evacuation-argon backfill cycles were performed. Benzylamine (1.0 to 1.5 eq.) was added via syringe, followed by LiHMDS (1 M THF solution, 2.5 eq.). If benzylamine is a solid, it is added together with the catalyst. The reaction mixture was stirred at 40 °C for 4-18 h. The reaction was monitored by LC/MS until complete conversion of 4-amino-3-bromopyridine. Upon completion of the reaction, the mixture was cooled to room temperature, diluted with dichloromethane and transferred to a partitioning funnel and layered with water. The organic phase was separated and the aqueous phase was extracted twice with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure to give the crude product 3-(benzylamino)-4-aminopyridine.
References
[1] Tetrahedron Letters, 2016, vol. 57, # 25, p. 2708 - 2712
