一种高效合成二氢黄酮类化合物的方法

An efficient method for the synthesis of dihydroflavones

提出了一种以2’-羟基查尔酮及其衍生物为原料,以乙醇作溶剂,采用多聚磷酸(PPA)/浓盐酸体系高效合成二氢黄酮类化合物的方法.对化合物a进行了条件优化,考察了反应时间、PPA的物质的量、V(浓盐酸)/V(乙醇)对化合物a产率的影响,得出合成化合物a的最优条件:反应物量为30.0 mg (0.1 mmol)、PPA的物质的量6.0 mmol,V(浓盐酸)/V(乙醇)=1/1,氮气保护下回流反应3 h.采用该方法以产率90.2%~93.6%合成得到5个二氢黄酮类化合物(a^f),所有化合物结构通过MS、1H NMR、13C NMR进行表征.该方法具有反应条件温和、反应时间短、产率高的优点.

An efficient method for the synthesis of dihydroflavones from 2’-hydroxychalcones with polyphosphoric acid(PPA)/concentrated hydrochloric acid system using ethanol as solvent was reported. Synthesis conditions of compound a were optimized. Effects of reaction time, volume ratio of concentrated hydrochloric acid to ethanol and PPA equivalent on the yield were investigated. The optimum conditions for the synthesis of compound a are obtained: when reactant was 30.0 mg(0.1 mmol), the amount of PPA was 6.0 mmol,V(concentrated hydrochloric acid)/V(ethanol) was 1/1, the reflux reaction time was 3 h under the protection of nitrogen. Five products(a-f) were synthesised in yields of 90.2%~93.6%, and were confirmed by MS, 1H NMR and 13C NMR. The method has the advantages such as mild reaction conditions, short reaction time and excellent yield.