N-Nitrosation of Secondary Amines Using p-TSA-NaNO2 as a Novel Nitrosating Agent Under Mild Conditions

A combination of p-toluenesulfonic acid (p-TSA) and sodium nitrite was used as a novel effective nitrosating agent for the N-nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in moderate to excellent yields.     

Brønsted Acid–Catalyzed Meyer–Schuster Rearrangement for the Synthesis of α,β-Unsaturated Carbonyl Compounds

An efficient and simple protocol for the Meyer–Schuster rearrangement of propargyl alcohols into α,β-unsaturated carbonyl compounds has been developed using catalytic amounts of p-toluenesulfonic acid in 1,2-dichloroethane.     

四氟硼酸根的离子排斥色谱-直接电导检测法分析

建立了离子排斥色谱-直接电导检测法分离测定四氟硼酸根的方法.以Shim-pack SCR-102H离子排斥色谱柱为分离柱,考察了淋洗液种类、浓度、色谱柱温度对四氟硼酸根测定的影响.最佳色谱条件为:以0.2 mmol/L p-甲苯磺酸溶液为流动相,流速1.0 mL/min,柱温40℃,进样体积20μL.在此条件下,四氟硼...     

Catalytic Systems Containing p-Toluenesulfonic Acid for the Coupling Reaction of Formaldehyde and Methyl Formate

The coupling reaction of formaldehyde(FA)and methyl formate(MF)to form methyl glycolate(MG)and methyl methoxy acetate(MMAc),catalyzed by p-toluenesulfonic acid(p-TsOH)as well as assisted by different kinds of solvents or Ni-containing compounds,had been investigated.The results showed that when the reaction was carried out at 140℃,with a molar ratio of FA to MF of 0.65:1, molar fraction of p-TsOH to total feedstock of 11.0%,and reaction time of 3 h,the yield of MG and MMAc was 31.1% and 17.1%,respectively,p-TsOH catalyzed the coupling reaction by means of the synergistic catalysis of protonic acidity and soft basicity.Adding extra solvents to the reaction system was unfavorable for the reaction.The composite catalytic system consisting of p-TsOH and NiX_2(X=Cl,Br,I)exhibited a high catalytic performance for the coupling reaction,and NiX_2 acted as a promoter in the reaction,whose promotion for the catalysis increased in the following order:NiCl_2相似文献   

2，6-氯苯甲醛新的合成方法

在水相中,以对甲苯磺酸为原料,以次氯酸、双氧水-氢溴酸分别作为芳香环及侧链的卤化试剂,经苯环氯化、去磺化、侧链溴代和二溴化苄水解4步反应合成了2,6-二氯苯甲醛,总收率为52．6％．     

2,6-二氯苯甲醛新的合成方法

在水相中,以对甲苯磺酸为原料,以次氯酸、双氧水-氢溴酸分别作为芳香环及侧链的卤化试剂,经苯环氯化、去磺化、侧链溴代和二溴化苄水解4步反应合成了2,6-二氯苯甲醛,总收率为52.6%.     

微波辐射在合成沙利度胺的铵盐类衍生物中的应用

沙利度胺(Thalidomide)又名反应停,化学名称为N-2-(2,6-二氧-3-哌啶基)-邻苯二甲酰亚胺[N-2-(2,6-dioxo-3-piperidinyl)-phthalidomide],是一种合成类谷氨酸衍生物,曾因致畸副作用而一度停止对其的研究[1].但上个世纪末期,Sampaio[2]等曾报道,沙利度胺可抑制体外LPS刺激原代人体单核细胞生成TNF-α,Kenyon[3]等的研究表明(S)-沙利度胺有着很强的抑制血管生成作用,再度引发了科学界对沙利度胺及其相关衍生物的研究兴趣.     

Determination of Cyclodextrin-Guest Association Constants by Competition with Indicator Dyes

Abstract

The competition of some biologically interesting guests with methyl orange and phenolphthalein indicators for α- and β-cyclodextrin, respectively, has been monitored using visible spectrophotometry. A mathematical model has been developed to calculate the cyclodextrin-guest association constants using a linear plotting method.     

A facile synthesis of α,α′-bis(substituted benzylidene) cycloalkanones catalyzed by p-TSA under solvent-free conditions

Abstract

Various 2,6-dibenzylidene cycloalkanones were readily prepared in a few minutes with good yields by simply mixing aromatic aldehydes with cycloalkanones in the presence of catalytic amounts of p-toluenesulfonic acid as a solid heterogeneous catalyst under solvent-free condition.