Microwave Assisted Reactions of Azaheterocycles Formedicinal Chemistry Applications

Microwave (MW) assisted reactions have became a powerful tool in azaheterocycles chemistry during the last decades. Five and six membered ring azaheterocycles are privileged scaffolds in modern medicinal chemistry possessing a large variety of biological activity. This review is focused on the recent relevant advances in the MW assisted reactions applied to azaheterocyclic derivatives and their medicinal chemistry applications from the last five years. The review is divided according to the main series of azaheterocycles, more precisely 5- and 6-membered ring azaheterocycles (with one, two, and more heteroatoms) and their fused analogues. In each case, the reaction pathways, the advantages of using MW, and considerations concerning biological activity of the obtained products were briefly presented.

Heterocycles [h]-fused onto 4-oxoquinoline-3-carboxylic acid. Part XII: synthesis of 5-fluoro-7-oxodihydo[1,3,4]thiadiazino [5,6-h]quinoline-8-carboxylic acid and ester

Direct interaction of dithizone with 7-chloro-6- fluoro-8-nitro-4-oxoquinoline-3-carboxylic acid or with its ester delivered the corresponding novel 1,3,4-thiadiazino [5,6-h]quinoline 3-carboxylic acid, or its ester which was then hydrolyzed to the respective acid. Structures of the latter tricyclic hybrids were deduced from analytical and spectral data and confirmed by single crystal X-ray structure determination of the ester derivative. The free acid showed moderate activity against Staphylococcus aureus with a MIC value of 25 μg mL−1.