5,7-二甲氧基-4-甲基苯酞和5,7-二羟基-4-甲基苯酞的新合成方法

New Synthetic Methods of 5,7-Dimethoxy-4-methylphthalide and 5,7-Dihydroxy-4-methylphthalide

以3,5-二甲氧基苯甲醇为起始原料,经过五步反应,合成了5,7-二甲氧基-4-甲基苯酞和5,7-二羟基-4-甲基苯酞这两个用于合成霉酚酸的重要中间体,产率分别达到80%和72%.6-氯甲基-2,4-二甲氧基苯甲醛经过亚氯酸钠氧化成酸的同时发生内酯化反应生成5,7-二甲氧基苯酞是最关键的一步.

5,7-Dimethoxy-4-methylphthalide and 5,7-dihydroxy-4-methylphthalide, two key intermediates in the synthesis of mycophenolic acid, were prepared from 3,5-dimethoxybenzyl alcohol in a five-step sequence with yields of 80% and 72%, respectively. The key process involved a transformation of 6-chloromethyl-2,4-dimethoxybenzaldehyde to 5,7-dimethoxyphthalide by an oxidation with sodium chlorite and a concomitant lactonization in one pot.