Synthesis was carried out using the method of Faul et al. To a suspension of acetonitrile (100 mL) and water (50 mL) containing N,O-dimethylhydroxylamine hydrochloride (7.07 g, 72.5 mmol) and K2CO3 (10.0 g, 72.5 mmol), 4-cyanobenzoyl chloride (8.00 g, 48.3 mmol) was slowly added. The reaction mixture was stirred at room temperature for 2 hours. Upon completion of the reaction, the solution was poured into water (50 mL) and extracted with ethyl acetate. The organic layers were combined, washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel column chromatography (250 mL of silica gel, eluent ratio tapered from hexane:ethyl acetate 45:55 to 1:1) to afford N-methoxy-N-methyl-4-cyanobenzamide (8.12 g, 88% yield) as a white crystalline solid. The product was characterized as follows: 1H NMR (400 MHz, CDCl3) δ 7.76 (d, J = 8.4 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 3.50 (s, 3H), 3.36 (s, 3H); 13C NMR (100.6 MHz, CDCl3) δ 167.8, 138.2, 131.8, 128.7, 118.1, 114.0, 61.2, 33.0; GC-MS (M)+ calculated value C10H10N2O2 190.0742, measured value 190.0739.
