厚朴酚合成方法的改进研究

Study on the improvement of synthesis for magnolol

本实验中,将2,2’-联苯二酚与1-溴丁烷经Williamson反应后,利用该反应产物溴化钠在酸性条件下与溴酸钠反应生成初生态的溴作为溴源,溴代反应得到5,5’-二溴-2,2’-二丁氧基联苯。中间产物5,5’-二溴-2,2’-二丁氧基联苯制成Grignard试剂后与烯丙基溴反应生成5,5’-二烯丙基-2,2’-二丁氧基联苯,最后在-20℃下,以三溴化硼为催化剂脱去丁基保护得到厚朴酚,产物纯度>98%,反应总产率为60.2%。

In the study,Williamson reaction was initiated between 2,2＇-dihydroxybiphenyl and n-butyl bromide.The product of the reaction,sodium bromide,was involved in reaction with sodium bromate in acid medium,to generate bromine in situ.Based on this,5,5＇-dibromo-2,2＇-dibutoxybiphenyl was achieved from bromination,and was then prepared into Grignard agent.Afterwards,5,5＇-diallyl-2,2＇-dibutoxybiphenyl was achieved from reaction between Grignard agent and allyl bromide.Finally,under-20℃ and protection by N2,cleavage of the butyl ethers with boron tribromide produced magnolol,which was higher than 98%in purity and was 60.2%in total yield.The structures of the compounds were confirmed by UV,IR,MS,1H NMR and 13C NMR.