An efficient enantioselective synthetic method for the synthesis of (2R)-5-phenyl-2-alkylproline tert-butyl esters was reported. The phase-transfer catalytic alkylation of tert-butyl-5-phenyl-3,4-dihydro-2H-pyrrole-2-carboxylate in the presence of chiral quaternary ammonium catalysts gave the corresponding alkylated products (up to 97% ee). The following diastereoselective reductions afforded c...

A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the simultaneous determination of folic acid (FA) and its active metabolite, 5-methyltetrahydrofolic acid (5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% (v/v) ammonium hydroxi...

The title compound, NH(4) (+)·C(2)H(8)NO(6)P(2) (-)·2H(2)O, was obtained by the reaction between 1-amino-ethane-1,1-diyldiphospho-nic acid and ammonium hydroxide (1:1) in an aqueous solution. The asymmetric unit contains one anion with two H atoms transferred from the phospho-nic acid groups to the amino group of the anion and to an ammonia mol-ecule, giving an ammonium cation. The structure di...

The reaction of 3-aminopropylamide of cholic acid with CS₂ produced a bile acid derivative of dithiocarbamic acid which further formed an ammonium salt with another molecule of 3-aminopropylamide of cholic acid. The cationic 3-ammonium propylamide of cholic acid did not react further with CS₂ and the formed salt was stable in the reaction mixture, even when excess CS₂ was used. When the reactio...

In this department, haemoglobinometry has been routinely carried out for more than six years on an AutoAnalyzer. The original oxyhaemoglobin method was described in this journal (Nelson and Lamont, 1961). The possibility of adapting this analytical technique to the estimation of haemoglobin by the more stable cyanmethaemoglobin method was tested by us and reported to be satisfactory at the Symp...

The Dion-Jacobson phase niobate perovskite, KCa2Nb3O10, was prepared by the polymerized complex (PC) method. The corresponding proton-exchanged material, HCa2Nb3O10, was then exfoliated by reaction with tetra(n-butyl)ammonium hydroxide (TBAOH), yielding unilamellar colloidal nanosheets whose lateral dimensions increased with the final calcination temperature in the PC synthesis. By restacking t...

Introduction A comprehensive review of gas-chromatographic methods for determining the concentration of circulating antiepileptic drug has been presented (1 ). Because most epileptic patients receive one or more drugs to control their seizures, it is therapeutically desirable to have a method for monitoring the concentrations of each of these drugs in serum. The chemistry of pyrolysis with meth...

poly(styrene-co-butyl acrylate)/clay nanocomposites were synthesized via in situ atom transfer radical polymerization using activators generated by electron transfer in the presence of a montmorillonite ion-exchanged with mixed surfactants of dodecyl trimethyl ammonium bromide and vinyl trimethyl ammonium chloride. the living nature of polymerization is confrmed by occurrence of narrow molecula...

Atomic layer deposition (ALD) provides a unique opportunity to integrate high-quality gate dielectrics on III–V compound semiconductors. The physics and chemistry of a III–V compound semiconductor surface or interface are problems so complex that even after three decades research understanding is still limited. We report a simplified surface preparation process using ammonium hydroxide (NH4OH) ...

A highly efficient tetra-(n-butyl)ammonium fluoride (TBAF)-promoted intramolecular cyclization of gem-dibromoolefins has been developed for the synthesis of 2-bromobenzofused heterocycles. The reaction provides a convenient approach to 2-bromobenzofurans(thiophenes) from the corresponding readily available gem-dibromovinyl substrates without a metal.