General procedure for the synthesis of (R)-3-methylmorpholine hydrochloride from the compound (CAS: 954133-47-2): to a solution of (5R)-4-(4-methoxybenzyl)-5-methylmorpholine (17.8 g, 80.3 mmol) in 1,2-dichloroethane (180 mL) was added 1-chloroethyl chloroformate (46 g, 322 mmol). The reaction mixture was stirred at 80 °C for 6 hours. Upon completion of the reaction, the solvent was removed by evaporation under reduced pressure. The residue was dissolved in methanol (180 mL) and stirred at 80 °C for 1 hour. The solvent was again removed by evaporation under reduced pressure and the residue was washed with ethyl acetate and dried to give (3R)-3-methylmorpholine hydrochloride (8.2 g, 59.6 mmol, 74% yield) as white crystals.