应用四甲基氢氧化铵控制电渗流的毛细管电泳方法分离多沙唑嗪及其中间体的对映体

建立了毛细管电泳手性分离多沙唑嗪中间体对映体的方法,并同时分离了多沙唑嗪对映体。考察了不同种类季铵盐对电渗流及分离的影响,其中四甲基氢氧化铵(TMB)能有效控制电渗流并提高组分的分离度。实验还考察了其他因素,如pH值、分离电压和磷酸二氢钠浓度对分离的影响。所用的毛细管为40cm(有效长度30cm)×50μm,缓冲液为12mmol/Lβ-环糊精、30mmol/L TMB、60mmol/L磷酸二氢钠(pH2.2),分离电压为20kV。在此条件下多沙唑嗪及其中间体的对映体均达到了基线分离。实验结果表明,一些用β-环糊精不能完全分离的对映体通过加入TMB控制电渗流能达到满意的分离效果。

2,3-二氯-6-硝基喹喔啉的合成

邻苯二胺和草酸二乙酯经闭环、硝化得6-硝基-1,4-二氢喹喔啉-2,3-二酮,经三氯氧磷和DMF氯代制得2,3-二氯-6-硝基喹喔啉,总收率约79%。

Synthesis and Crystal Structure of o-Methylisourea Hydrosulfate

To determine the structure of o-methylisourea for instructing its application and factory production, crystalline o-methylisourea hydrosulfate was synthesized in this paper by methylation of urea with dimethylsulfate, followed by acidification in 53% yield. Its single crystal prepared from 95% ethanol is determined by X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 8.5330（10）, b = 7.0548（9）, c = 11.6764（14） A°, β = 95.429（2）°, Mr = 172.16, V= 699.75（15）A°^3, Dc = 1.634 g/cm^3, Z = 4, F（000） = 360 andμ（MoKα） = 0.435 mm^-1. Of 1511 unique reflections, 1294 is gotten （I 〉 2σ（I））. The structure was solved by Fourier method and refined to R = 0.0438 and wR = 0.1209. The crystal structure shows that o-methylisourea combines with bisulfate via the intramolecular hydrogen bond between N（2）-H（4） of o-methylisourea and O（2） of bisulfate. As a result, the molecular structure is [H2NC（OCH3）NH2]HSO4 and the formula is C2H8N2O5S or C2H7N2O·HSO4 but not H2NC（OCH3）NH-HSO4 or H2NC（OCH3）NH·0.5H2SO4.

红花及其白花变种中总黄酮及山柰酚-3-O-芸香糖苷的含量测定

目的测定川红花及红花变种白花中总黄酮及山柰酚-3-O-芸香糖苷的含量。方法用UV法测定总黄酮的含量;HPLC法测定山柰酚-3-O-芸香糖苷的含量,采用Diamonsil C18色谱柱(250 mm×4.6 mm,5μm),流动相为乙腈-水-冰醋酸(25:74:1),流速1.0 mL.min-1,柱温30℃,检测波长265 nm。结果 UV法测得川红花中总黄酮含量为7.43%,红花变种白花为20.28%;HPLC法测得川红花中山柰酚-3-O-芸香糖苷的含量为0.41%,红花变种白花为13.86%。结论红花变种白花中总黄酮及山柰酚-3-O-芸香糖苷的含量均高于川红花,具有较高的研究价值。