1.2 g of silica gel was added to 11.6 g (100 mmol, 1 eq.) of methyl acetoacetate. To this was added 9.25 g (120 mmol, 1.2 eq.) of methylamine solution (40% aqueous solution) and the mixture was stirred overnight. The reaction mixture was extracted with dichloromethane (DCM), dried with anhydrous magnesium sulfate (MgSO?), filtered and the solvent was evaporated to give the yellow oily product methyl 3-(methylamino)but-2-enoate in 12.21 g, 95% yield.1H-NMR (CDCl?, δ/ppm): 8.47 (s, NH, 1H), 4.47 (s, CH, 1H). 3.61 (s, OCH?, 3H), 2.91 (d, NHCH?, J = 5.22 Hz, 3H), 1.92 (s, CH?, 3H).
