4 resultados para RAPID SYNTHESIS
em Aston University Research Archive
Resumo:
A low energy route for the removal of Pluronic P123 surfactant template during the synthesis of SBA-15 mesoporous silicas is explored. The conventional reflux of the hybrid inorganic-organic intermediate formed during co-condensation routes to Pr-SOH-SBA-15 is slow, utilises large solvent volumes, and requires 24 h to remove ∼90% of the organic template. In contrast, room temperature ultrasonication in a small methanol volume achieves the same degree of template extraction in only 5 min, with a 99.9% energy saving and 90% solvent reduction, without compromising the textural, acidic or catalytic properties of the resultant Pr-SOH-SBA-15. © 2014 The Royal Society of Chemistry.
Resumo:
A rapid one-pot synthesis of 3-alkyl-5-[(Z)-arylmethylidene]-1,3-thiazolidine-2,4-dionesis described that occurs in recyclable ionic liquid [bmim]PF6 (1-butyl-3-methylimidazolium hexafluorophosphate).Significant rate enhancement and good selectivity have been observed.
Resumo:
A series of N1-benzylideneheteroarylcarboxamidrazones was prepared in an automated fashion, and tested against Mycobacterium fortuitum in a rapid screen for antimycobacterial activity. Many of the compounds from this series were also tested against Mycobacterium tuberculosis, and the usefulness as M.fortuitum as a rapid, initial screen for anti-tubercular activity evaluated. Various deletions were made to the N1-benzylideneheteroarylcarboxamidrazone structure in order to establish the minimum structural requirements for activity. The N1-benzylideneheteroarylcarbox-amidrazones were then subjected to molecular modelling studies and their activities against M.fortuitum and M.tuberculosis were analysed using quantitative structure-analysis relationship (QSAR) techniques in the computational package TSAR (Oxford Molecular Ltd.). A set of equations predictive of antimycobacterial activity was hereby obtained. The series of N1-benzylidenehetero-arylcarboxamidrazones was also tested against a multidrug-resistant strain of Staphylococcus aureus (MRSA), followed by a panel of Gram-positive and Gram-negative bacteria, if activity was observed for MRSA. A set of antimycobacterial N1-benzylideneheteroarylcarboxamidrazones was hereby discovered, the best of which had MICs against m. fortuitum in the range 4-8μgml-1 and displayed 94% inhibition of M.tuberculosis at a concentration of 6.25μgml-1. The antimycobacterial activity of these compounds appeared to be specific, since the same compounds were shown to be inactive against other classes of organisms. Compounds which were found to be sufficiently active in any screen were also tested for their toxicity against human mononuclear leucocytes. Polyethylene glycol (PEG) was used as a soluble polymeric support for the synthesis of some fatty acid derivatives, containing an isoxazoline group, which may inhibit mycolic acid synthesis in mycobacteria. Both the PEG-bound products and the cleaved, isolated products themselves were tested against M.fortuitum and some low levels of antimycobacterial activity were observed, which may serve as lead compounds for further studies.
Resumo:
The application of heterogeneous catalysts for the manufacture of renewable biodiesel fuels offers an exciting, alternative clean chemical technology to current energy intensive processes employing soluble base catalysts. We recently synthesised tuneable MgO nanocrystals as efficent solid base catalysts for biodiesel synthesis, and have developed a simple X-ray spectroscopic method to quantitatively determine surface basicity, thereby providing a rapid screening tool for predicting the reactivity of new solid base catalysts. Promotion of these MgO nanocrystals through Cs doping dramatically enhances biodiesel production rates due to the formaion of a mixed Cs Mg(CO ) phase. These MgO derived nanocatalysts permit energy efficent, continuous processing of diverse, sustainable oil feedstocks in flow reactors.