摘要
以工业级的3,5-二甲氧基苯甲酸为起始原料,与L iH于室温下在四氢呋喃中反应5 h生成3,5-二甲氧基苯甲酸锂(Ⅰ),不需精制,直接与正丁基锂在冰浴中进行酰化反应制得3,5-二甲氧基苯戊酮(Ⅱ),收率85.06%;进而在210℃以下通过乌尔夫-黄鸣龙反应将Ⅱ还原为3,5-二甲氧基戊苯(Ⅲ),Ⅲ与熔融的吡啶盐酸盐在200℃回流2 h,脱甲基制得目标产物3,5-二羟基戊苯(Ⅳ),总收率为60.90%,质量分数为98.22%。利用IR1、HNMR、GC、HLPC-MS等分析手段对各步产物进行了表征。结果表明:该文所提出合成路线是可行的,具有工艺简单、收率高等特点,优于目前所报道的其他合成路线。目前正在进行放大实验。
A new process for the preparation of 3,5-dihydroxy-l-pentylbenzene which is used as medicinal intermediate and raw material for the synthesis of HIV restrainer was proposed in this paper. Technical 3,5-dimethoxybenzoic acid reacted with lithium hydride to form salt（ Ⅰ ）which acylated n- butyllithium directly to give 1-（3,5-dimethoxyphenyl）-1-pentanone（ Ⅱ ）in 85.06% yield. Then Ⅱ was reduced through Wolff-K-Huangminglong reaction at 210 ℃ to give 3,5-dimethoxy-1- pentylbenzene （ Ⅲ ）. Finally, Ⅲ refluxed with melt pyridine hydrochloride at 200 ℃ for 2 h to afford the target product 3,5-dihydroxy-1-pentylbenzene（ Ⅳ ）. The total yield of Ⅳ amounted to 60.90% and its mass percentage was 98.22%. The products were characterized by means of IR,^1HNMR, GC and HLPC - MS. The results indicated that this synthesis route was feasible, characterized by simple process and high yield,superior to the published ones. Enlarged preparation experiment is being carried out now.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2006年第4期382-385,共4页
Fine Chemicals
