反应详情

To a stirred solution of 4-methoxy-phenylamine (1.24 g) in methanol (15 mL) at ambient temperature was added successively, glacial acetic acid (415 mg), acetone (669 mg), and 1M sodium cyanoborohydride in THF (12.7 mL). The reaction mixture was stirred overnight at room temperature. The pH was adjusted to 2 with 6N HCl and stirred for 30 minutes after which time the excess sodium cyanoborohydride was completely quenched. The pH was then adjusted to 8.5 with 1N NaOH and the resultant solution extracted with diethyl ether (2×50 mL) and ethyl acetate (50 mL). The oganic extracts were combined, dried over sodium sulfate, filtered and concentrated under reduced pressure to give the title compound (1.42 g) as a yellow oil. 1H NMR (300 MHz, CDCl3): d 1.18(d, J=6.1 Hz, 6H), 2.92(br s, 1H), 3.55(m, 1H), 3.75(s, 3H), 6.57(d, J=9.1 Hz, 2H), 6.78(d, J=8.8 Hz, 2H) TLC (EtOAc/Hex (2:3)): Rf =0.72.

1. customwas completely quenched
2. extractionthe resultant solution extracted with diethyl ether (2×50 mL) and ethyl acetate (50 mL)
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure