6-甲氧基-7-乙氧基-4-氯喹啉的合成改进

以2-甲氧基-5-硝基苯酚为起始原料,经过O-烷基化、还原、高温合环、水解、脱羧、氯化6步反应,得到目标产物6-甲氧基-7-乙氧基-4-氯喹啉,总收率为24%。O-烷基化过程中,通过对丙酮、乙腈、DMF做溶剂的对比,发现乙腈做溶剂时,不仅产率较高,且后处理简单。在高温合环过程引入"一锅法"和"无溶剂法",不仅简化操作步骤,提高产率,而且降低了反应的污染。

Improvements on the Synthesis of 6-methoxy-7-ethoxy-4-Chloroquinoline

The synthetic methods were studied for 6-methoxy-7-ethoxy-4-chloroquinoline in details. The 2-methoxy-5-nitrophenol was used as the raw material and the title compound was obtained via the O-alkylation, reduction reaction, thermal cyclization, hydrolysis, decarboxylation and chloration. The overall yield was 24%. During the O-alkylation process, compared to the acetone, acetonitrile and DMF, the acetonitrile was proved to be the optimal solvent, which gave rise to the yield increased and the aftertreatment simplified. In addition, one-pot synthesis and without solvent method was bought into the high temperature cyclization process. The one-pot method can greatly simplify the operation and improve the yield. The solvent-free reaction can reduce consumption and pollution. This method can provide an experimental basis for its application with the advantages of simple operation and higher yield from convenient raw materials.