General procedure for the synthesis of 2-aminomethyl-4-(4-fluorobenzyl)-morpholine from N-(2,3-epoxypropyl)phthalimide and 2-(4-fluorobenzylamino)ethanol: 2-(4-fluorobenzylamino)ethanol (28.7 g, 0.17 mol) and N-(2,3-epoxypropyl)phthalimide (35.0 g, 0.13 mol) were added to the reaction kettle. The reaction was heated to 70-80°C and held for 3 hours. Subsequently, sulfuric acid was slowly added dropwise at 70-90°C and the reaction was continued at 125-145°C for 2.5 hours. Upon completion of the reaction, the mixture was transferred to cold water, cooled to 0°C, crystallized and filtered. The filtrate was neutralized with sodium hydroxide, extracted with chloroform, dried the organic phase and concentrated to dryness to give 4-(4-fluorobenzyl)-2-aminomethylmorpholine as a light yellow oil (yield: 75.1%, purity: 80.2%).