162576-01-4

1221593-52-7

162576-01-4

Preparation 56: Synthesis of benzyl (2-aminoethyl)(methyl)carbamate hydrochloride (C). To a solution of compound B (311 mmol) in methanol (MeOH, 1.2 L) was added a solution of lithium hydroxide (LiOH, 14.9 g, 622 mmol) in water (120 mL). The reaction mixture was stirred at room temperature for 3 hours. The solvent was concentrated under reduced pressure to 75% of the original volume and subsequently diluted with water (400 mL). The solution was extracted with ethyl acetate (EtOAc, 2 x 300 mL). The organic layers were combined, washed with saturated saline (200 mL), dried over anhydrous magnesium sulfate (MgSO4) and concentrated under reduced pressure. The residue was dissolved in ether (300 mL) and treated with 2N hydrochloric acid/ether solution (200 mL). The precipitate formed was collected by filtration, washed with ether and dried under vacuum to afford the hydrochloride of compound C (67.8 g, 89% yield) as a white solid.LC-MS [M + H]+ 209.0 (C11H16N2O2 + H, calculated value: 209.3). Compound C was used directly in the form of N,N-dimethylformamide (DMF) solution for subsequent reactions without further purification.