General procedure for the synthesis of 3-methyl-4-morpholinoaniline from 4-(2-methyl-4-nitrophenyl)morpholine: a mixture of 4-(2-methyl-4-nitrophenyl)morpholine (6 g, 0.0645 mol, 1.0 eq.) and zinc powder (8.64 g, 0.135 mol, 5 eq.) in methanol (50 mL) in a round-bottomed flask was placed under stirring conditions . Ammonium chloride (7.29 g, 0.135 mol, 5 eq.) was slowly added at 0 °C, followed by stirring the reaction mixture at room temperature for 1 h, during which the progress of the reaction was monitored by thin layer chromatography (TLC). After completion of the reaction, the reaction mixture was filtered through a bed of diatomaceous earth and the filtrate was concentrated under reduced pressure to obtain the residue. The residue was diluted with dichloromethane (DCM, 150 mL) and washed with water. The organic layer was separated, washed with brine solution, dried over anhydrous sodium sulfate, and finally concentrated under reduced pressure to give 3-methyl-4-morpholinoaniline as a brown solid (5 g, 96.35% yield).1H NMR (400 MHz, CDCl3) data: δ 6.768 (d, 1H), 6.39 (s, 1H), 6.36 (d, 1H), 4.66 ( brs, 2H), 3.681 (t, 4H), 2.683 (t, 4H), 2.124 (s, 3H).
