Microwave assisted organic synthesis-a review

This work was supported by the Foundation for Science and Technology (FCT), Portugal (projects PTDC/QUI-QUI/113687/2009 and PEst-C/QUI/UI0081/2013). A.G. (SFRH/BD/43531/2008) and M.J.M. (SFRH/BD/61262/2009) thank FCT for grants.

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Chromone: A Valid Scaffold in Medicinal Chemistry

Chromones as a privileged scaffold in drug discovery: a review.

Compounds useful for treating cellular proliferative diseases and disorders by modulating the activity of KSP are disclosed.

Compounds, compositions, and methods

John Rawls's A Theory of Justice is one of the most influential works of legal and political theory published since the Second World War. It provides a memorably well-constructed and sustained argument in favour of a new (social contract) version of the meaning of social justice. In setting out this argument, Rawls aims to construct a viable, systematic doctrine designed to ensure that the process of maximizing good is both conscious and coherent – and the result is a work that foregrounds the critical thinking skill of reasoning. Rawls's focus falls equally on discussions of the failings of existing systems – not least among them Marxism and Utilitarianism – and on explanation of his own new theory of justice. By illustrating how he arrived at his conclusions, and by clearly explaining and justifying his own liberal, pluralist values, Rawls is able to produce a well structured argument that is fully focused on the need to persuade. 
Rawls explicitly explains his goals. He discusses other ways of conceptualizing a just society and deals with counter-arguments by explaining his objections to them. Then, carefully and methodically, he defines a number of concepts and tools—“thought experiments”—that help the reader to follow his reasoning and test his ideas. Rawls’s hypothesis is that his ideas about justice can be universally applied: they can be accepted as rational in any society at any time.

An Analysis of John Rawls's A Theory of Justice

The synthesis of the biologically active novel systems derived from reaction of 3-formylchromones with three types of amino derivatives, 6-R2-2-aminobenzothiazoles, 6-amino-2-R3-thiobenzothiazoles and hydrazide derivatives (derived from cyanoacetic, isonicotine, salicylic and gallic acids) was carried out. The structures of the prepared compounds have been proved by elemental analysis, 1H NMR and IR spectra. Antimicrobial activity was studied against the following microorganisms — bacteria G+ (Staphylococcus aureus 29 58 , Bacillus subtilis 18 66 ), G− (Escherichia coli 326 71 , Pseudomonas aeruginosa); yeasts; Candida albicans, Saccharomyces cerevisiae; moulds; Microsporum gypseum, Aspergillus niger, Scopulariopsis brevicaulis; and against typical and atypical mycobacteria: Mycobacterium tuberculosis (H37Rv), Mycobacterium kansasii (PFG 8), Mycobacterium avium (My 80 72 ), Mycobacterium fortuitum (1021). The hereditary bleaching effect on the plastid system of Euglena gracilis, a unique phenomenon of the biological activity of chromone derivatives, is reported. The bleaching test on E. gracilis is used for detecting extranuclear mutations.

Synthesis, antimicrobial activity and bleaching effect of some reaction products of 4-oxo-4H-benzopyran-3-carboxaldehydes with aminobenzothiazoles and hydrazides

Microwaves assisted Gabriel synthesis of phthalides

Reaction of 3-formylchromones with aromatic amino carboxylic acids

One-pot and facile preparations of 6-(2-hydroxy-5-R-benzoyl)-4-methyl-2-R1- pyrazolo[3,4-b]pyridines 4a-o are described, using the reaction of 3-formyl chromones 1 with 5-amino-1-R1-pyrazoles 2. An enamine-intermediate 2-ethyloxy-6-R-3-(3-methyl-1- phenylpyrazol-5-ylaminomethylene)chroman-4-one 3 was isolated at lower temperatures. Acyloxy-derivatives 5 of compounds 4 were obtained by acylation with acid chlorides or acid anhydrides. Coumarins 6 substituted at the 3- and 4-positions were prepared from the pyrazolo[3,4-b]pyridines 4 by condensation reactions and hydrazones 7 were formed from their reaction with 2,4-dinitrophenyl hydrazine. Reactions under microwave irradiation proceeded significantly faster and with high yields.

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3-Formylchromones IV. The rearrangement of 3-formylchromone enamines as a simple, facile route to novel pyrazolo[3,4-b]pyridines and the synthetic utility of the latter.

The synthesis of methyl 4-(methoxymethyl)furo[3,2-b]pyrrole-5-carboxylate (1d) and methyl 2formyl-4-(methoxymethyl)furo[3,2-b]pyrrole-5-carboxylate (2d) is described. The effect of microwave irradiation on the condensation reactions of methyl 2-formylfuro[3,2-b]pyrrole-5carboxylates 2a-2d and methyl 2-formylfuro[2,3-b]pyrrole-5-carboxylates 3a-3d with active methylene compounds as are: 2-thioxothiazolidine-4-one (rhodanine), 2-thioxoimidazolidine-4one (thiohydantoine), and 3-amino-2-thioxothiazolidine-4-one (3-aminorhodanine) was studied and compared with "classical" conditions. The results show that microwave irradiation shortens the reaction time while maintaining comparable yields.

Jarmila Chovancová

Papers

Synthesis, antimicrobial activity and bleaching effect of some reaction products of 4-oxo-4H-benzopyran-3-carboxaldehydes with aminobenzothiazoles and hydrazides

Microwaves assisted Gabriel synthesis of phthalides

Reaction of 3-formylchromones with aromatic amino carboxylic acids

3-Formylchromones IV. The rearrangement of 3-formylchromone enamines as a simple, facile route to novel pyrazolo[3,4-b]pyridines and the synthetic utility of the latter.

Effect of microwave irradiation on reaction of furo[3,2-b]pyrrole and furo[2,3-b]pyrrole-2-carbaldehydes with some active methylene compounds