Novel 1,2,3,4‐Tetrahydroquinazolinones via Reaction of 2‐Amino‐N‐substituted Benzamides and Dimethyl Acetylenedicarboxylate

Reaction of 2‐amino‐N‐substituted benzamides and dimethyl acetylenedicarboxylate (DMAD) in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in H₂O at room temperature led to the formation of novel 1,2,3,4‐tetrahydroquinazolinones.     

Perovskite ceramics and recent experimental progress in reactor design for chemical looping combustion application

Chemical looping combustion (CLC) is a novel method of carbon capture and sequestration. It facilitates CO₂ capture by lower energy penalties compared with other methods in this category. The major challenges encountered in CLC are oxygen carrier, reactor and fuel-type selection. A proper combination of these factors is required for an efficient CLC. There have been several studies with regard to oxygen carriers applicable to these processes: novel oxygen carriers, single perovskites and potential oxygen carriers, double perovskites, have been investigated for their oxygen capture and release properties in a number of studies. Different kinds of reactors have also been proposed for use in CLC processes. This paper presents information on the materials capable of oxygen storage and release and the different kinds of reactors investigated for CLC in different studies. It has been shown that, although there are several oxygen carriers and reactors with the desired function and efficiency for CLC, there remains the need for further improvement and optimisation in both areas. © 2014 Institute of Chemistry, Slovak Academy of Sciences     

Molecular dynamics simulation of the sliding of distamycin anticancer drug along DNA: interactions and sequence selectivity

Molecular dynamics simulations and umbrella sampling have been used to investigate the sliding of distamycin anticancer drug along the DNA minor groove. The potential energy surface calculated for the sliding of drug shows three minima. The global minimum corresponds to the binding of drug to the AT-rich region, which is the origin of sequence selectivity of distamycin. This selectivity originates from both structural factors and energy contributions. The analysis of energy contributions of binding was performed by the MM–PBSA method. The analysis of hydrogen bonds and van der Waals, electrostatic, and solvation interactions show that structural or steric factors are more important in the selectivity of distamycin than energetic factors. The results of this study can be applied in the design of new derivatives of distamycin anticancer drug with improved properties.     

Novel Four-Step Synthesis of Thioxo-quinazolino[3,4-a]quinazolinone Derivatives

A novel synthesis of thioxo-quinazolino[3,4-a]quinazolinone framework was developed through a four-step reaction starting from isatoic anhydride. The resulting 2-aminobenzamides from the reaction of isatoic anhydride and different amines underwent coupling–cyclization reaction with 2-nitrobenzaldehydes, reduction of nitro group, and then cyclization reaction with carbon disulfide (CS₂). All steps were carried out under easy and user-friendly conditions in a short time without using expensive catalysts or reagents.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Vilsmeier Reagent: An Efficient Reagent for the Transformation of 2-Aminobenzamides into Quinazolin-4(3H)-one Derivatives

Clean and easy preparation of quinazolin-4(3H)-one derivatives using 2-aminobenzamides and Vilsmeier reagent is described. 2-Aminobenzamides were converted into the corresponding quinazolinones under mild and efficient conditions, in good yields without undesirable by-products.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Gold-catalysed synthesis of amino acid-derived 2,5-disubstituted oxazoles

Amino acid-derived propargylic amides are cyclised in a one-pot, Au(III)-catalysed operation to yield 5-bromomethyl oxazoles. These compounds are further elaborated to bis-heterocycles, dipeptide mimics and more.     

Study of the interglobular structure of metal powders obtained by a borohydride reduction process

The effect of borohydride reduction duration and magnetic field in the specific surface area, metal particle size and form, and form and dimensions of the textural arrangement of pores in metal powders is investigated. It is established that the particle chains formed involve interglobular voids, i.e. the chains may be considered as consisting of successivly ordered globule layers. The interglobular void is found to possess definite dimensions and configuration. Powders obtained in a magnetic field have tetrahedral voids, while octahedral voids correspond to powders prepared without a magnetic field. The magnetic parameters of the powders have displayed a similar difference which needs additional studies.     

Mathematical programming in subsistence agriculture

This paper examines the use of mathematical programming models in subsistence agriculture as an example of the use of operational research in developing countries. Differences from developed agriculture are described, and five mathematical programming formulations to cater for the major differences are given. Examples of the use of such models in published literature to produce policy oriented conclusions are summarised. This exemplified a more general point that mathematical O.R. formulations are relevant to policy issues in developing countries providing they are modifications of formulations used in developed countries.