Synthesis and potentiometric analysis of organophosphorus metal complexones and complexonates based on 2-aminothiazole derivatives

Synthesis conditions of 4-phenyl-2-amidothiazolyl acetate and 2-thiourido-4-diethylphosphothiazole were developed, and the complexation capacity of these compounds in formation of mixed-ligand complexes was studied. The optimal conditions and thermodynamic parameters of the complexation process were determined. The potentiometric method was used to find thermodynamic parameters of the reactions of mixed-ligand complexation with copper(II) and lead(II) ions, the composition of the complexes being formed on the basis of 4-phenyl-2-aminothiazole and its phosphorylated derivatives was determined.     

Structure of the product of the complete hydrolysis of 1,2-bisdiazoacetylethane

Conclusions The product of the complete hydrolysis of 1,2-bisdiazoacetylethane in aqueous HClO₄, is 2,5-dioxo-1,6-hexanediol, whose structure was established by x-ray diffraction structural and analysis. UV spectroscopy indicates that this compound does not undergo keto-equal tautomerism characteristic for-hydroxy ketone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1184–1187, May, 1985.     

Formation of anionic σ-aryl complexes of platinum (IV) in the reaction of H2PtCl6 with aromatic compounds. The crystal and molecular structures of platinum (IV) complexes of naphthalene and ortho-nitrotoluene

The crystal and molecular structures of anionic platinum(IV) complexes of naphthalene (I) and ortho-nitrotoluene (II) have been determined by X-ray diffraction. The structures of both complexes are similar. The platinum atom is octahedrally coordinated with four chlorine atoms occupying the equatorial positions and σ-bonded aryl and neutral ammonia ligands situated in the axial positions.     

Hexafluoroacetone as a Protecting and Activating Reagent. Regioselective Esterification of Aspartic, Malic, and Thiomalic Acid

Summary. Hexafluoroacetone reacts with -functionalized ,-dicarboxy acids like aspartic, malic, and thiomalic acid to give exclusively five-membered lactones. The -carboxylic groups remain unaffected and can be derivatized separately. They can be linked i.a. to orthogonal protecting groups or multivalent alcohols like pentaerythritol to give synthetically valuable building blocks.     

Quantitative Assessment of Serine-8 Phosphorylated β-Amyloid Using MALDI-TOF Mass Spectrometry

The study of the molecular mechanisms of the pathogenesis of Alzheimer’s disease (AD) is extremely important for identifying potential therapeutic targets as well as early markers. In this regard, the study of the role of post-translational modifications (PTMs) of β-amyloid (Aβ) peptides is of particular relevance. Serine-8 phosphorylated forms (pSer8-Aβ) have been shown to have an increased aggregation capacity and may reflect the severity of amyloidosis. Here, an approach for quantitative assessment of pSer8-Aβ based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is proposed. The relative fraction of pSer8-Aβ was estimated in the total Aβ-pool with a detection limit of 1 fmol for pSer8-Aβ (1–16) and an accuracy of 2% for measurements in the reflectron mode. The sensitivity of the developed method is suitable for determining the proportion of phosphorylated peptides in biological samples.     

Broadband self-phase modulation, cross-phase modulation, and four-wave mixing in 9-mm-long AlGaAs waveguides

We demonstrate efficient self-phase modulation with a nonlinear phase shift of up to 3π, broadband cross-phase modulation, and four-wave mixing with a 14 nm tunability range in AlGaAs waveguides with a specially designed composition. The length of our sample is only 9 mm, but the efficiency of the observed effects is high.     

Sometimes intermediates. Do the job!

The SARS coronavirus main proteinase is a prime target for antiviral therapy. In this issue of Chemistry & Biology, Wu et al. describe potent inhibition of the enzyme by benzotriazole esters, which were originally obtained as intermediates in the synthesis of lopinavir derivatives .