利用1,2,3-三甲氧基苯合成2,3,4,4′-四羟基二苯甲酮

Synthesis of 2,3,4,4′-Tetrahydroxybenzophenone from 1,2,3-Trimethoxybenzene

为解决2,3,4,4′-四羟基二苯甲酮(4HBP)的传统合成方法中原料易氧化的问题,采用羟基保护方法,以1,2,3-三甲氧基苯(TMB)和对甲氧基苯甲酸(p-AA)为原料、伊顿试剂为催化剂,1,2-二氯乙烷为溶剂,首次合成重要的中间体化合物2,3,4,4′-四甲氧基二苯甲酮(4TMP),然后在BBr3/CH2Cl2体系、无水无氧、低温的条件下,将4TMP进行脱甲基反应高效合成了目标产物4HBP,目标产物收率约为86.4%,纯度≥97.59%,各金属离子均小于18.60mg/kg。通过红外光谱、核磁共振谱、质谱等方法确证了中间产物和目标产物的结构。

To prevent the oxidation of raw materials(pyrogallic acid and p-hydroxybenzoic acid)during the traditional synthesis of 2,3,4,4′-tetrahydroxybenzophenone(4HBP),an intermediate compound,2,3,4,4′-tetramethoxydibenzone(4TMP),was synthesized for the first time by the hydroxyl protection method.1,2,3-trimethoxybenzene(TMB)and p-anisic acid(p-AA)were used as the raw materials,and Eaton reagent and 1,2-dichloroethane were used as the catalyst and solvent,respectively.The target product,2,3,4,4′-tetrahydroxybenzophenone,was synthesized by demethylation of the intermediate in a BBr 3/CH 2 Cl 2 system with anhydrous,anaerobic and low temperature conditions.The yield of the target product was approximately 86.4%,and the purity was≥98.8%,the content of each metal ion was less than 18.60 mg/kg.The structures of the intermediate and target products were investigated by IR,NMR,and MS.