40608-76-2

103-82-2

102-51-2

40608-76-2

GENERAL METHOD: Under stirring conditions, 4-methoxy-o-phenylenediamine (1.85 mmol) was dissolved in xylene (10 mL), followed by the addition of phenylacetic acid (2.77 mmol) and boric acid (0.185 mmol). The reaction mixture was refluxed for 16 hours. After completion of the reaction, it was cooled to room temperature, the reaction mixture was concentrated under reduced pressure and diluted with ethyl acetate (50 mL). The organic phase was washed with saturated sodium bicarbonate solution (2 x 50 mL), dried over anhydrous sodium sulfate and subsequently concentrated under reduced pressure. Purification of the residue by silica gel column chromatography (eluent: 10-15% hexane solution of ethyl acetate) afforded 2-benzyl-5-methoxy-1H-benzo[d]imidazole (3u) in 67% yield; white solid; melting point 109-111 °C; IR (KBr) 3009, 2847, 1510, 1466, 1410, 1248, 1175, 1029, 775 cm^-1; 1H NMR (400 MHz, DMSO-d6) δ 12.04-12.14 (m, 1H), 7.18-7.44 (m, 6H), 6.91-7.07 (m, 1H), 6.70-6.79 (m, 1H), 4.12 (s, 2H), 3.75 (s, 3H); 13C NMR (100 MHz, DMSO-d6) δ 155.5, 137.9, 128.8, 128.5, 126.6, 118.7, 110.1, 101.3, 94.5, 55.4, 34.9; HRMS calculated value of C15H14N2O m/z 238.1182, measured value 238.1180.