共查询到19条相似文献,搜索用时 46 毫秒
2.
1,4-二氢吡啶衍生物是一类重要的有机化合物,以苯甲醛、乙酰乙酸乙酯和碳酸氢铵为原料一步合成了2,6-二甲基-4-苯基-3,5-二乙氧基羰基-1,4-二氢吡啶。该方法具有原料易得、产率高、环境友好等优点。 相似文献
3.
In this paper a simple preparative method for isolation and purification of ginkgolides A and B was developed,As starting material,a commercially available standardized ginkgo extract (EGb761,containing 24% flavonoid and 6% terpene trilactones) was used,After a pretreatment step,optimized by the uniform design method ,the concentrated intermediate extract with high content of GA and gb( 90%) was separated into the individual terpenes by preparative liquid chromatography eluted with petroleum ether-ethylacetate,Analysis of products was carried out by means of HPLC-ELSD(evaporative light -scattering detector),The results show that ginkgolides A and B are obtained in higher yield and better purity. 相似文献
4.
建立了银杏内酯B脂微球中银杏内酯B的含量测定方法。采用HPLC法,色谱柱为C18柱(250mm×4.6mm,5μm),流动相为甲醇-四氢呋喃-水(25∶10∶65),流速为1.0mL·min-1,柱温为30℃,蒸发光散射检测器,载气压力为4.0bar,漂移管温度40℃。结果银杏内酯B在80.91~269.70μg·m L-1时,线性关系良好(r=0.9998),平均加样回收率为100.25%,RSD为1.44%。该法准确,重现性好,可用于银杏内酯B脂微球中银杏内酯B的含量测定。 相似文献
5.
6.
7.
8.
9.
10.
11.
12.
13.
Kurt Geibel Franz Strohmer Albert Hammerschmidt 《Advanced Synthesis \u0026amp; Catalysis》1991,333(6):895-900
Semiempirical Calculation and Synthesis of Substituted 1,4-Dihydropyridines Semiempirical calculations of 1,4-dihydropyridines ( 1 – 16 ) done by the programme AMPAC show good consistence between the calculated and the measured absorption maxima at long wavelength. The presented calculation method can be applied to this class of compounds. Correlations between geometry, substitution, conformation, absorption behavior and limitations of the method are discussed. 相似文献
14.
以单羰基姜黄素衍生物为先导,将具有优良生物活性的肟酯基团与1,4-戊二烯-3-酮结构有机结合,设计合成了11个含肟酯结构的1,4-戊二烯-3-酮类化合物,其结构经红外光谱、核磁共振波谱、液相质谱和元素分析确证。初步生物活性测试结果表明:在质量浓度为500 mg/L时,化合物Ⅴa对烟草花叶病毒(TMV)治疗活性为61.3%,与其对照药剂宁南霉素(64.6%)相当;化合物Ⅴe对TMV的治疗活性为91.2%,与对照药剂宁南霉素(97.3%)相当。在药剂质量浓度为50 mg/L时,化合物Ⅴf对小麦赤霉病菌、水稻纹枯病菌和苹果腐烂病菌具有中等程度的抑制活性,其抑制率分别为48.1%、56.5%和66.1%。在药剂质量浓度为100 mg/L时,化合物Ⅴi对小菜蛾和蚜虫具有一定程度的触杀活性,其抑制率分别为61.5%和42.4%。以上活性数据表明:1,4-戊二烯-3-酮肟酯类化合物具有一定的抗植物病毒、抑菌和杀虫活性,在其结构基础上进行适当的改造,有望得到具有良好生物活性的化合物。 相似文献
15.
Pd/C-catalyzed transfer hydrogenation with Hantzsch ester1,4-dihydropyridine was found to be very effective for the selective reduction of N-(alkoxy(aryl)methyl) benzamide compounds to the corresponding benzamides. The reaction conditions, solvent effects, and reaction mechanism were discussed in the present work. 相似文献
16.
17.
以3种不同的路径分别合成了阿司匹林-维生素E酯的中间体,并通过红外光谱、高效液相色谱、核磁共振等手段对产物的结构进行了表征,证明所得均为目标产物。通过比较,确定以酰氯为酰化剂的合成方法产率较高,成本低,适合工业化生产。 相似文献
18.