Amidoalkylation of Phosphorus Trichloride with Acetamide and Functionalized Cyclic Ketones-Evidence of Dominating Role of Side-Reactions

Abstract

The course of the reaction between phosphorus trichloride, acetamide and ethyl oxoalkanecarboxylates was studied in terms of the production of side-products. When ethyl 2-oxocycloalkane- and 4-oxocyclohexanecarboxylates were used as substrates, not only mixtures of the expected products—aminophosphonocycloalkanecarboxylic acids and their ethyl esters but also the formation of three side-products, namely 1-aminocycloalkanephosphonic acids (products of decarboxylation of the latter ones) and 1-aminoethane-1,1-diphosphonic and 1-hydroxyethane-1,1diphosphonic acids (products of the reaction of substrate and solvent with phosphonylating agent) were observed. Ethyl 2-oxo-cyclooctanecarboxylate afforded the expected 2-amino-2-pohosphonocyclooctanecarboxylic acid in minute amounts. For comparison reactions of 1-butyloxocarbonyloxopiperidines afforded the desired aminopiperidinephosphonic acids in good yields and without formation of side-products.     

The differences in thermal profiles between normal and leukemic cells exposed to anticancer drug evaluated by differential scanning calorimetry

Chronic lymphocytic leukemia (CLL) is a heterogenous disease with an imbalance between apoptosis and cell proliferation. Therefore, the main goal in CLL therapy is to induce apoptosis and effectively support this process in transformed B lymphocytes. In the current study, we have compared differential scanning calorimetry (DSC) profiles of nuclei isolated from CLL cells and normal mononuclear cells exposed to cladribine or fludarabine combined with mafosfamide (CM; FM), and additionally to CM combined with monoclonal antibody—rituximab (RCM) for 48 h, as well as in culture medium only (controls). Under current study, the mononuclear cells from peripheral blood (PBMCs) of healthy individuals have been included. The obtained results have shown the presence of thermal transition at 95 ± 5 °C in most of nuclear preparations (92.2 %) isolated from blood of CLL patients. This thermal characteristic parameter was changed after drug exposure, however, to a different extent. These thermal changes were accompanied by the decrease of cell viability, an elevation of apoptosis rate and the changes in expression/proteolysis of poly(ADP-ribose)polymerase-1—main marker of apoptosis. Importantly, in DSC profiles of nuclear preparations of PBMCs from blood of healthy donors exposed to investigated drug combinations and control CLL cells, the lack of such changes was observed. Our results confirmed that DSC technique complemented with other biological approaches could be helpful in tailoring therapy for CLL patients.     

Beams of electromagnetic radiation carrying angular momentum: The Riemann-Silberstein vector and the classical-quantum correspondence

All beams of electromagnetic radiation are made of photons. Therefore, it is important to find a precise relationship between the classical properties of the beam and the quantum characteristics of the photons that make a particular beam. It is shown that this relationship is best expressed in terms of the Riemann-Silberstein vector - a complex combination of the electric and magnetic field vectors - that plays the role of the photon wave function. The Whittaker representation of this vector in terms of a single complex function satisfying the wave equation greatly simplifies the analysis. Bessel beams, exact Laguerre-Gauss beams, and other related beams of electromagnetic radiation can be described in a unified fashion. The appropriate photon quantum numbers for these beams are identified. Special emphasis is put on the angular momentum of a single photon and its connection with the angular momentum of the beam.     

Efficient resolution of 2,2′-dihydroxy-1,1′-binaphthalene-4,4′- and 6,6′-dicarboxylic acid by complexation with cinchonidine and brucine

2,2′-Dihydroxy-1,1′-binaphthalene-4,4′- and 6,6′-dicarboxylic acid were resolved efficiently by complexation with cinchonidine and brucine, respectively. The absolute configurations of these compounds were determined by X-ray crystallographic analyses.     

Complexes of vanadium(III) with aromatic amino acids and l-proline in aqueous solution

The equilibria of the complexation processes of V³⁺ ion with l-phenylalanine, l-tyrosine, l-tryptophan and l-proline in aqueous solution were studied by potentiometric and spectroscopic (UV, Vis, CD) methods. The results indicate that all ligands (except l-tyrosine) form only 1:1 species with vanadium(III) ion in the pH range about 2–5. More complex equilibria were observed in the vanadium(III)–l-tyrosine system. Only in this system relatively stable ML₂ species predominantly exists in the pH range 3–5. The results of spectroscopic measurements indicate that in ML and ML₂ species chelated bounds through O and N atoms appear in all investigated systems. Above pH 5 strong hydrolysis processes of vanadium(III) occurred.     

On non‐compact logics in NEXT(KTB)

In this paper we construct a continuum of logics, extensions of the modal logic T₂ = KTB ⊕ □²p → □³p, which are non‐compact (relative to Kripke frames) and hence Kripke incomplete. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A method of desingularization for analytic two-dimensional vector field families

It is well known that isolated singularities of two dimensional analytic vector fields can be desingularized: after a finite number of blowing up operations we obtain a vector field that exhibits only elementary singularities. In the present paper we introduce a similar method to simplify the periodic limit sets of analytic families of vector fields. Although the method is applied here only to reduce to families in which the zero set has codimension at least two, we conjecture that it can be used in general. This is related to the famouss Hibert's problem about planar vector fields.     

Use of isothermal microcalorimetry in pharmaceutical preformulation studies,Part II. Amorphous phase quantification in a predominantly crystalline phase

Low amounts of amorphous phase present in predominantly crystalline powders were quantified by using various analytical techniques with an emphasis on the use of Isothermal Perfusion Microcalorimetry. The amorphous phase was plasticized using ethanol vapor and enthalpy of re-crystallization of amorphous phase was used for generation of a calibration curve. Amorphous content as low as 5% was quantified using this technique. Although baseline noise was very low, additional processes occurring during re-crystallization confounded quantification of lower amorphous fractions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and Tuberculostatic Activity of Some 2-Piperazinmethylene Derivatives 1,2,4-Triazole-3-Thiones

Abstract

The Mannich reaction's products of 1,2,4-triazole-3-thiones, substituted in position 4 (with ethyl, allyl, phenyl, Ph-4-Br) or 5 (with phenyl, Ph-4-OH, Ph-3,4,5-(OMe)₃, 2-phenyl) were obtained. Their amino-components were 1-phenylpiperazine, 1-(4-fluorophenyl)-piperazine, 1-benzylpiperazine, 1-(2-pyridyl)-piperazine and 1-piperonyl-piperazine. Tuberculostatic activity of the compounds obtained was tested and their MIC values within 25–100 mcg/mL.     

The Lalonde-McDuff conjecture for nilmanifolds

We prove that any Hamiltonian bundle whose fiber is a nilmanifold c-splits.