Synthesis, SAR, and antibacterial activity of novel oxazolidinone analogues possessing urea functionality

The syntheses of a number of novel oxazolidinone analogues possessing an urea functionality are reported. While the urea derivatives possessing aliphatic and aromatic groups were prepared by the more conventional isocyanate method, the derivatives possessing heterocyclic rings were synthesized by a relatively uncommon but otherwise efficient carbamate chemistry. Though the SAR resulted in novel compounds possessing in vitro activity equivalent to Linezolid, the compounds possess a range of substituents that are amenable for altering physicochemical properties of the resultant drug. The antibacterial activity was found to be not sensitive to the functional groups attached to the urea site regardless of the size and electronic characteristics. Based on in vivo results, one molecule has been identified as a candidate and additional work such as salt selection, scale-up, etc., are currently underway to take the molecule further through development

Current research trends in external energy assisted machining

External energy assisted machining involves the use of a heating, cooling, and mechanical vibration source to facilitate the material removal process. A drastic attention on the external energy assistance is resulted from the requirements for newly developed hard and brittle materials machining and many activities to understand the mechanisms, processes, and the systems have been performed on both micro and macro scale in recent years. This paper attempts to provide an overview in the general idea of these areas with laser and plasma, cryogenic, and vibration assistances. The progresses made up to date will be explained in detail and finally, the future research directions in this area will be discussed.close1