卤代5-羟基黄酮衍生物的合成及工艺研究

Synthesis and Optimization of Halo-substituted 5-Hydroxyflavone Derivatives

以Baker-Venkataraman方法经过酯化、重排和关环3步反应合成了4个卤代5-羟基黄酮衍生物4a~4d和5-羟基黄酮4e,并以4a为例优化了合成工艺。考查了投料比、反应时间或N2保护等因素对合成工艺的影响,并对反应机理进行了探讨。根据优化的合成工艺,4a~4e合成的每步反应收率在50%以上,3步反应总收率为15%~20%。该工艺条件温和,操作简单,可以高效率地合成5-羟基黄酮衍生物。合成的目标化合物结构经过1H NMR和MS确证。

Four halo-substituted 5-hydroxyflavone derivatives 4a~4d and 5-hydroxyflavone 4e were synthesized according to the Baker-Venkataraman method via esterification, rearrangement and ring closure. Then, the synthesis of 4a, taken as an example, was optimized. The optimized contents contained mole ratio of materials, reaction time or N2protection, and so on. Moreover, the reaction mechanism was discussed. According to the optimized synthesis process,the reaction yields of each steps of compounds 4a~4e were above 50%, and the total yields of three-step were 15%~20%. The optimized process was mild and simply operated, and the 5-hydroxyflavone derivatives could be efficiently synthesized. The target compounds were confirmed by 1H NMR and MS.