Synthesis
To a solution of 3-methoxybenzaldehyde (180 g, 1.32 mol) in methanol (1 L) was slowly added 40% aqueous methylamine (113 mL, 1.31 mol), and the reaction mixture was stirred at 0 °C for 1 hour. Subsequently, sodium borohydride (75 g, 1.98 mol) was added in batches at the same temperature and stirring was continued for 1 hour. Upon completion of the reaction, the solution was concentrated under reduced pressure to a smaller volume, diluted with water (200 mL) and extracted with dichloromethane (3 x 500 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product N-methyl-3-methoxybenzylamine (220 g, quantitatively) as a clear oil, which was used directly in the subsequent reaction without further purification.1H NMR (CDCl3, 500 MHz) δ: 7.23 (t, J = 8.0 Hz, 1H), 6.92-6.88 (m, 2H), 6.81-6.78 (m, 2H), 6.81-6.78 (m, 2H), 6.81-6.78 (m, 2H). 6.81-6.78 (m, 1H), 3.80 (s, 3H), 3.73 (s, 2H), 2.45 (s, 3H), 2.07 (br s, 1H).
References
[1] Patent: WO2010/132437, 2010, A1. Location in patent: Page/Page column 74; 101-102
[2] Patent: WO2009/149258, 2009, A2. Location in patent: Page/Page column 19; 23
[3] Patent: US2007/21408, 2007, A1. Location in patent: Page/Page column 57; 59; 60; 62; 63; 64-65; 66; 70; 71; 73; 74; 88
[4] Patent: US2014/275101, 2014, A1. Location in patent: Paragraph 0072; 0074; 0075
[5] Synthesis, 1990, # 3, p. 253 - 255
