苯甲醚利用LiCl脱甲基

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当邻位和对位有吸电子基团存在时,此体系去甲基化容易进行。此条件下,乙基和异丙基也可以脱去。底物中有醛和酯时,去甲基需要更长的时间,但产率还是很好的。底物中有甲酯会去甲基形成酸。


Cleavage of 2,3-Dimethoxybenzaldehyde.   2,3-Dimethoxybenzaldehyde (1.0 g,6 mmol) and LiCl (0.76 g,18 mmol) are heated in boiling DMF (10 mL), the reaction being monitored by GLC. When the starting material disappears, 10% aqueous NaOH (30 mL) is added;the solution is washed with ether (2×25 mL), then acidified with 10%aqueous HCl (50 mL), and extracted with ether (2×25 mL). The organic phase is washedwith brine (30 mL), dried (sodium sulfate) and concentrated in a rotaryevaporator to afford 2-hydroxy-3-methoxybenzaldehyde (0.88 g, 98%).


【A.M. Bernard, M. R. Ghiani, P. P. Piras and A. Rivoldini, Synthesis,1989, 287



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