7-甲氧基-3′-羟基黄酮的合成及其紫外光谱性能

黄酮有很好的药理活性,应用广泛,但提取黄酮产量低、价格高,为了探索人工合成黄酮的新技术和合成新的黄酮,以天然产物丹皮酚为原料,碱催化间羟基苯甲醛和丹皮酚发生缩合反应,构建中间体产物Ⅰ;再在高温下以二甲基亚砜(DMSO)为溶剂,碘催化诱导其氧化关环得到目标产物Ⅱ,通过紫外、红外、元素分析及核磁共振等综合分析确定产物的结构,考察产物Ⅰ和产物Ⅱ在不同浓度酸碱盐溶液中紫外光谱的变化情况并分析其原因。结果表明,产物Ⅰ为2′,3-二羟基-4′-甲氧基查尔酮,产率82.2%,在不同浓度酸碱盐溶液中其紫外光谱均有变化,可与低浓度NaOH溶液作用,其生成物在30 min内能稳定存在,也易与KNO₃溶液作用,其生成物不稳定;产物Ⅱ为7-甲氧基-3′-羟基黄酮,产率92.0%,在HCl(4.0 mol/L)、NaOH、KNO₃溶液中能长期稳定存在。该合成工艺克服了缩合反应中需要保护羟基的问题,实现了7-甲氧基-3′-羟基黄酮的高效合成,产物Ⅰ未能形成4-色酮结构,其AB环上各有一个酚羟基,稳定性受环境影响较大,碱性环境下尤为突出,使用时应把控产物Ⅰ的存储环境,pH...

Synthesis of 7-Methoxyl-3"-hydroxyflavones and Its Ultraviolet Spectral Properties

2",3-Dihydroxy-4"-methoxychalcone was synthesized by the condensation reaction with 3-hydroxybenzaldehyde and paeonol occurred under the alkaline catalysis, this product molecular structure was determined by comprehensive analysis such as UV, IR, elemental analysis and NMR including of ¹HMNR, ¹³C NMR and 135^°dept, its yield was 82.2%, then and 7-methoxy-3"-hydroxyflavone was synthesized by base iodine catalyzed closing ring reactions to 2",3-dihydroxy-4"-methoxychalcone with DMSO as solvent at high temperature, the flavones" yield was 92.0%, this synthetic reaction could overcome the problem of protecting the hydroxyl group in the condensation reaction and realized the efficient synthesis of 7-methoxy-3"-hydroxyflavone. The changes of UV spectra of 2",3-dihydroxy-4"-methoxychalcone and 7-methoxy-3"-hydroxyflavone were investigated in acid, alkali and salt solutions of their different concentrations respectively, 2",3-dihydroxy-4"-methoxychalcone could react in HCl solution of 4 mol?L^-1 concentration, and also reacted in low-concentration NaOH solution, its variable substance could exist stably within 30 min, it easily reacted in KNO3 solution, the degree of reaction increased with the increase of the concentration of KNO3 solution and this variable substance could not exist stably for a long time. 7-methoxy-3"-hydroxyflavone could exist stably in HCl, NaOH and KNO3 solutions of their different concentrations for a long time.