Synthesis
General procedure for the synthesis of 4-nitrobenzylamine hydrochloride from p-nitrobenzonitrile: To a 6.0 mL solution of toluene containing p-nitrobenzonitrile (1.0 g, 5.1 mmol, 1.0 eq.) under nitrogen protection was added TMDS (900 μL, 5.1 mmol, 1.0 eq.) or PMHS (610 μL, 10.2 mmol, 2.0 eq.) and Ti(Oi-Pr)4 (1.5 mL, 5.1 mmol, 1.0 eq.). The reaction mixture was heated at 60 °C for 24 h, during which the colorless solution gradually changed to black, and the reaction progress could be monitored by TLC or 1H NMR. Upon completion of the reaction, the mixture was cooled to room temperature and acidified with 1 M aqueous HCl (7.7 mL, 1.5 eq.) to obtain a clarified solution. Subsequently, the crude product was concentrated under reduced pressure, and the resulting solid was filtered and washed with pentane (3 x 50 mL). The washed solid was dissolved in ethanol and finally the filtrate was concentrated under reduced pressure to give the target product 4-nitrobenzylamine hydrochloride.
References
[1] Tetrahedron, 2014, vol. 70, # 4, p. 975 - 983
[2] Tetrahedron Letters, 2009, vol. 50, # 50, p. 7005 - 7007
[3] Recueil des Travaux Chimiques des Pays-Bas, 1992, vol. 111, # 1, p. 22 - 28
[4] Journal of Organic Chemistry, 2015, vol. 80, # 14, p. 7281 - 7287
