Convenient and Efficient Preparation of Ethyl 6-n-Decyloxy-7-ethoxy-4-hydroxyquinoline-3-carboxylate

Ethyl 6-N-decyloxy-7-ethoxy-4-hydroxyquinoline-3-carboxylate has been synthesized from pyrocatechol in six steps and in 39.3% overall yield.     

A cation trap for anodic stripping voltammetry: NH3–plasma treated carbon nanotubes for adsorption and detection of metal ions

NH₃–plasma treated multi-walled carbon nanotubes (pn-MWCNTs) with cation traps for the detection of ultratrace quantities of Zn(II), Cd(II), Cu(II), and Hg(II) using square wave anodic stripping voltammetry (SWASV) is described. The pn-MWCNTs use their adsorption performance to enhance the sensitivity. It is found that under optimized conditions Zn(II), Cd(II), Cu(II) and Hg(II) were individually detected at potentials of −1.16, −0.78, −0.268 and 0.108 V, respectively. The detection limit (3σ method) of 0.314, 0.0272, 0.2263, and 0.1439 nM toward Zn(II), Cd(II), Cu(II), and Hg(II) is achievable, respectively. No interference could be seen during the simultaneous detection of Zn(II), Cd(II), Cu(II), and Hg(II). The pn-MWCNTs exhibit excellent selectivity owing to the different ability of adsorption. A study of the ability of pn-MWCNTs in practical application is carried out using a sample of water collected from Dongpu Reservoir in Hefei City, Anhui, China. It is found that the results were favorable when compared against inductively coupled plasma atomic emission spectrometry (ICP-AES) analysis.     

Expedient Strategy for the Synthesis of 5-Acylethynylpyrrole-2-carbaldehydes

5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al₂O₃ medium (room temperature, 6 h, 41–54% yields).     

Combined use of ionic liquid and β‐CD for enantioseparation of 12 pharmaceuticals using CE

In this study, the enantioseparation of zopiclone, repaglinide, chlorphenamine maleate, brompheniramine maleate, dioxopromethazine hydrochloride, promethazine hydrochloride, liarozole, carvedilol, homatropine hydrobromide, homatropine methylbromide, venlafaxine, and sibutramine hydrochloride has been investigated using β‐CD in combination with a chiral ionic liquid (IL), 1‐ethyl‐3‐methylimidazolium‐L‐lactate. The influence of the type of IL and its concentration, BGE pH, and chain length of the IL cations on the resolution are discussed. Finally, the proposed method was successfully applied for the chiral impurity determination of eszopiclone in pharmaceutical tablets after validation with respect to accuracy and precision, linearity range, selectivity, repeatability, LOD and LOQ. It is assessed that the chiral impurity determination in the commercial tables is fewer than 0.1%.     

One-Pot Palladium-Catalyzed Ligand- and Metal-Oxidant-Free Aerobic Oxidative Isocyanide Insertion Leading to 2-Amino-substituted-4(3H)-quinazolinones

An efficient, ligand- and metal-oxidant-free, one-pot, cascade aerobic oxidative, palladium-catalyzed, multicomponent reaction has been developed through isocyanide insertion of less active secondary amide and aromatic amine, which leads to 2-amino-substituted-4(3H)-quinazolinones. This approach proves to be one of the simplest methods for the synthesis of this class of valuable bioactive heterocyclic scaffolds.     

Uv Dye Lasers

The moat important property of visible dye lasere, that is continuous wave length tuning, stimulated the search for dyes capable to lase UV. And they were founed in 1668¹. Now the need In tunable UV laeers for applications in spectroacopy, photochemistry, isotope separation, remote air and sea probing, etc. ie only more clearly Been. The object of thie paper is to review shortly some recent advances In UV dye lasers.     

La(O-i-Pr)3 CATALYZED THREE-COMPONENT CONDENSATION REACTION: A CONVENIENT SYNTHESIS OF N,N-DIALKYL-α-CYANOAMINES

ABSTRACT

In the presence of 10 mol% of La(O-i-Pr)₃, a three-component condensation reaction of aldehyde, secondary amine and trimethylsilylcyanide proceeded smoothly to afford N,N-dialkyl-α-cyanoamine in good yield.     

Influence of an Oxidising Impurity on Preparation of 2-Lithio-1,3-dithiane: Isolation of bis[2-d,3-Dithianyl)]methanol

Bis-dithianylalkanols and dimers are formed in preparation of 2-lithio-1,3-dithianes due to the presence of oxidising impurity in n-BuLi (perhaps n-BuOOLi).