刺乌头碱氢溴酸盐的合成及晶体结构

报道了以双溴代烷烃和刺乌头碱合成刺乌头碱氢溴酸盐的方法. 用元素分析、红外光谱、高分辨质谱和核磁共振进行了表征. 并用X射线单晶衍射确定了标题化合物的绝对构型. 晶体结构表明, 该化合物通过分子间氢键形成了网状类似超分子结构. 晶体属于单斜晶系, P2₁空间群, 晶胞参数: a＝1.0619(2) nm, b＝1.2196(3) nm, c＝1.2282(2) nm, β＝90.87(1)°, V＝1.59037(54) nm³, Z＝2, D_m＝1.428 g/cm^－3, F(000)＝720.0, µ＝1.349 mm^－1. 环 A, B, C, D, E和F分别呈船式、椅式、信封式、船式、船式和信封式. 其绝对构型被确定为1S,4S,5S,7S,8S,9S,10S,11S,13R,14S,16S,17R.     

刺乌头碱的提取与其氢溴酸盐的合成及表征

刺乌头碱;刺乌头碱氢溴酸盐;合成;提取;表征     

一些中环二胺氢溴酸盐的合成

以1,3－二氯－2－丙醇及N,N′－二对甲苯磺酰胺（2a,2b)为起始原料,通过关环反应合成新化合物（3a,3b),然后脱去3a,3b的对甲苯磺酰胺,得到标题化合物（4a,4b）。本文从分子内与分子间反应的竞争及反应物2a,2b的分子结构两方面讨论了对关环反应产率的影响。     

一种合成氢溴酸达菲那新的新方法

以(S)-N-BOC-3-羟基吡咯烷为原料,依次经Mitsunobu反应,酰胺化和脱保护反应,再与5-（2-氯乙基）-2,3-二氢苯并呋喃缩合后成盐合成了高纯度的氢溴酸达菲那新,其结构经¹H NMR, MS（ESI）和元素分析确证,总收率约35%。     

金属醇盐的合成及应用

金属醇盐,又称金属酸酯或金属烷氧基化合物,是被人誉为填补了有机化学和无机化学之间空白的广义金属有机化合物的一部分。它们的分子结构中至少有一个M—O—C(M     

示波极谱滴定法测定生物碱氢溴酸盐类药物

以ＡｇＮＯ３作滴定剂，ＫＮＯ３和磺基水杨酸为极谱底液，采用交流示波极谱滴定法测定氢溴酸山莨菪碱、氢溴酸东莨菪碱、氢溴酸加兰他敏三种生物碱氢溴酸盐类药物的含量。该法到目前为止未见报道，具有快速、准确、终点直观的特点。     

新杀菌剂嘧霉胺盐的合成

合成了20个具有生物活性的嘧霉胺盐,其中19个为首次报道的新化合物.结构组成经元素分析、IR及1H NMR确证.初步的生物活性测试结果表明大多数化合物具有较好的抑菌及杀菌作用,探讨了嘧霉胺盐的结构与杀菌活性的关系.     

嘧霉胺盐的合成及其杀菌活性测试

合成了10个嘧霉胺盐,其中9个为新化合物。其结构经^1HNMR,IR和元素分析确证。初步杀菌活性测试结果表明大部分化合物对被测菌种有较好的抑菌和杀菌作用,并对化合物结构与杀菌活性的关系进行了初步探讨。     

六齿咪唑鎓盐的合成

1991年Arduengo第一次分离得到N-杂环卡宾。它与叔膦配体一样,都是优良的电子给体,且与金属形成反馈键,被称为“仿膦配体”（phosphine mimics）,它的反应活性高,应用于各种催化反应中。但是许多N-杂环卡宾在空气中易水解,形成脂肪族化合物。人们常先合成其前体咪唑翁盐,然后采用原位配制的方法制备其金属络合物催化各种有机反应。多齿配体配位的多齿过渡金属络合物对小分子的活化和功能化具有非常好的催化作用。     

新型手性季鏻盐的合成

以(S)-联萘酚为原料,与三氟甲磺酸酐反应制得联萘酚三氟甲磺酸酯(2);2在Ni(dppp)Cl2催化下与碘甲烷格氏试剂反应得2,2’-二甲基联萘(3);3经溴代反应得2,2’-二溴甲基联萘4;4与1,3-双(二苯基膦)丙烷(dppp)在甲苯中回流合成了一个新型的联萘酚衍生的双中心手性季鏻盐,其结构经1H NMR,31P NMR和FT-IR表征。     

One-pot synthesis of ω-bromoesters from aromatic aldehydes and diols using pyridinium hydrobromide perbromide

A simple and efficient one-pot procedure has been developed for the synthesis of ω-bromoesters from aromatic aldehydes and diols in the presence of pyridinium hydrobromide perbromide (PHPB) and triethoxymethane in which aldehyde reacts first with diol and the product, cyclic acetal, reacts with PHPB to give the final product, ω-bromoesters.     

Kinetics and mechanism of oxidation of phosphorus oxyacids by pyridinium hydrobromide perbromide

Oxidation of three lower oxyacids of phosphorus, viz. phosphinic, phenylphosphinic and phosphorous acids by pyridinium hydrobromide perbromide (PHPB), is first-order with respect to both oxyacid and PHPB. There is no effect on addition of acylonitrile and pyridinium bromide. On oxidation, deuterated phosphinic and phosphorous acids exhibit substantial kinetic isotope effects. The effect of solvent composition on reaction rate indicates that the transition state is more polar than the reactants. Reaction rates were determined at different temperatures and the activation parameters calculated. Alternative mechanisms, involving the two tautomeric forms of the oxyacid, have been formulated and it has been concluded that the reaction proceeds through the pentacoordinated tautomer. Transfer of a hydride ion from the oxyacid to PHPB, in the rate-determining step, has been proposed.     

Simultaneous determination of lappaconitine hydrobromide and isopropiram fumarate in rabbit plasma by capillary electrophoresis with electrochemiluminescence detection

A CE electrochemiluminescence (CE-ECL) method for simultaneous determination of lappaconitine hydrobromide (LH) and isopropiram fumarate (IF) has been first established, with a chemically modified platinum electrode by europium (III)-doped Prussian blue analogue film as a working electrode. The conditions for CE separation and ECL detection are discussed and optimized in detail. It has been proved that 20 mmol/L phosphate buffer (pH 8.5) containing 5% (v/v) ACN and 0.17 mol/L SDS could achieve the most favorable resolution, and the high sensitivity of detection was obtained by maintaining the detection potential at 1.23 V. Under optimized conditions, a baseline separation for the two analytes was achieved within 6 min, and the standard curves were linear in the range of 1.0×10(-7) ～ 5.0 × 10(-5) g/mL for LH and 4.0 × 10(-8) ～ 1.0 × 10(-5) g/mL for IF with the detection limits (3σ) of 6.6 × 10(-8) g/mL for LH and 3.7 × 10(-8) g/mL for IF, respectively. The precisions of intra- and interday measurements for LH and IF were less than 4.21 and 2.61%, respectively. The applicability of the proposed method was illustrated in the determination of LH and IF in rabbit plasma with recoveries between 95.6 and 103.0%.     

A facile and convenient method for the conversion of thioamides into amides using pyridinium hydrobromide perbromide

Selective transformation of thioamides to their corresponding carbonyl compounds are performed in high to excellent yields under mild conditions using pyridinium hydrobromide perbromide (PHBP) as a mild and efficient reagent. Correspondence: Moslem M. Lakouraj, Department of Organic Chemistry, Faculty of Chemistry, Mazandaran University, Babolsar 47416, Iran.     

Simultaneous determination of acetaminophen, dextromethorphen hydrobromide and pseudoephedrine hydrochloride in a new drug formulation for cold treatment by HPLC

Summary A rapid and accurate HPLC method is described for the simultaneous determination of acetaminophen, dextromethorphen hydrobromide and pseudoephedrine hydrochloride in a new cold formulation. Chromatographic separation of the three pharmaceuticals was performed on a Hypersil CN column (150×5.0 mm, 5 μm) with a mobile phase mixture of an ion-pairing solution, methanol and acetonitrile (25:57:18, v/v), at a flow rate of 1.0 mL min⁻¹, with detection at 220 nm. Separation was complete in less than 10 min. The method was validated for linearity, accuracy, precision, limit of quantitation and robustness. Linearity, accuracy, and precision were found to be acceptable over the ranges of 2.06∼20.6 μg·mL⁻¹ for acetaminophen, 0.202∼2.02 mg·mL⁻¹ for pseudoephedrine hydrochloride and 0.042∼1.06 mg·mL⁻¹ for dextromethorphen hydrobromide.     

A multivariate quantification of Box‐Behnken design assisted method development and validation of dextromethorphan hydrobromide and desloratadine simultaneously by reverse‐phase HPLC in in‐house syrup formulation

An innovative high‐performance liquid chromatography assay method was developed and validated for quantification of dextromethorphan hydrobromide and desloratadine simultaneously in monophasic liquid formulation by preparing syrup containing 30 mg/5 mL of dextromethorphan hydrobromide and 1.2 mg/mL of desloratadine. The chromatographic severance was executed by gradient solution A and B. The composition of buffer solution A contained 0.05 M monobasic potassium, then 1 mL triethylamine was added to it and the pH was adjusted to 2.3 with orthophosphoric acid. Methanol was used as solution B. The gradient elution was executed with Kromasil C8 (250 mm × 4.6 mm) column having 1.5 mL/min flow rate and 20 µL injection volume with UV‐estimation at 254 nm for dextromethorphan hydrobromide and DES. The present research was planned according to Box‐Behnken design by utilizing design expert software, using four factors such as column temperature (A), flow rate (B), mobile phase–organic phase (C), and pH (D); correspondingly the selected response variables were resolution between A and B, that is, desloratadine and methyl paraben (Y1), tailing of dextromethorphan hydrobromide (Y2), and tailing of desloratadine (Y3). The parameters such as system suitability, linearity, accuracy, precision, robustness, limit of detection, limit of quantitation, and ruggedness were analyzed to validate the developed method in accordance with current regulatory guidelines.     

Synthesis of fused indazole ring systems and application to nigeglanine hydrobromide

The single-step synthesis of fused tricyclic pyridazino[1,2-a]indazolium ring systems is described. Structural details revealed by crystallography explain the unexpected reactivity. The method is applied to the gram scale synthesis of nigeglanine hydrobromide.