Liguzinediol的合成工艺优化
Improved Synthesis of Liguzinediol
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摘要: 确定并优化Liguzinediol的合成工艺。方法 以乙酰乙酸乙酯为起始原料,经亚硝化、Pd/C催化氢化、缩合、脱氢、硼氢化钠还原得到Liguzinediol,并对各步反应条件进行优化。结果 制备2-羟亚氨-3-氧代丁酸乙酯时,原料与亚硝酸钠当量比为1∶1.4,亚硝酸钠水溶液的浓度为16%最佳;制备3,6-二甲基吡嗪-2,5-二甲酸二乙酯时,反应温度30℃、1当量三乙胺、反应溶剂乙醇与原料质量比为8.8最佳;制备Liguzinediol时,反应溶剂为THF和EtOH、3当量硼氢化钠、2当量无水氯化钙、反应温度为室温最佳。产品总收率49.1%,纯度99.91%。结论 此路线所用原料均廉价易得,反应条件温和,收率提高至49.1%,产品质量可控,便于放大生产。Abstract: OBJECTIVE To identify and optimize the synthesis of liguzinediol. METHODS Ethyl acetoacetate was used as the starting material to obtain liguzinediol by nitration, Pd/C catalytic hydrogenation, condensation, dehydrogenation and sodium borohydride reduction. The reaction conditions were optimized. RESULTS When ethyl N-hydroxyiminoacetoacetate was prepared, the ratio of the raw material to sodium nitrite was 1∶ 1.4, the concentration of sodium nitrite aqueous solution was 16%. When diethyl 3,6-dimethyl-2,5-pyrazinedicarbonate was prepared, the reaction temperature was 30℃, 1 equivalent of trimethylamine, and the mass ratio of ethanol to the raw material was 8.8. When liguzinediol was prepared, the reaction solvents were THF and EtOH, 3 equivalents of sodium borohydride, 2 equivalents of anhydrous calcium chloride, and the reaction temperature was room temperature. The total product yield was 49.1%, while the purity was 99.91%. CONCLUSION The raw materials used in this route are cheap and easy to obtain, the reaction conditions are mild, the yield is increased to 49.1%, the product quality is controllable, and it is easy to enlarge the production.