Effective microwave-assisted approach to 1,2,3-triazolobenzodiazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition

A novel catalyst-free synthetic approach to 1,2,3-triazolobenzodiazepinones has been developed and optimized. The Ugi reaction of 2-azidobenzaldehyde, various amines, isocyanides, and acids followed by microwave-assisted intramolecular azide–alkyne cycloaddition (IAAC) gave a series of target heterocyclic compounds in moderate to excellent yields. Surprisingly, the normally required ruthenium-based catalysts were found to not affect the IAAC, only making isolation of the target compounds harder while the microwave-assisted catalyst-free conditions were effective for both terminal and non-terminal alkyne

FDA-Approved Oximes and Their Significance in Medicinal Chemistry

Despite the scientific advancements, organophosphate (OP) poisoning continues to be a major threat to humans, accounting for nearly one million poisoning cases every year leading to at least 20,000 deaths worldwide. Oximes represent the most important class in medicinal chemistry, renowned for their widespread applications as OP antidotes, drugs and intermediates for the synthesis of several pharmacological derivatives. Common oxime based reactivators or nerve antidotes include pralidoxime, obidoxime, HI-6, trimedoxime and methoxime, among which pralidoxime is the only FDA-approved drug. Cephalosporins are β-lactam based antibiotics and serve as widely acclaimed tools in fighting bacterial infections. Oxime based cephalosporins have emerged as an important class of drugs with improved efficacy and a broad spectrum of anti-microbial activity against Gram-positive and Gram-negative pathogens. Among the several oxime based derivatives, cefuroxime, ceftizoxime, cefpodoxime and cefmenoxime are the FDA approved oxime-based antibiotics. Given the pharmacological significance of oximes, in the present paper, we put together all the FDA-approved oximes and discuss their mechanism of action, pharmacokinetics and synthesis

Synthesis of 1- (3- (1- substituted- 1,2,3- triazol- 4- yl)- 1,2,4- triazol- 5- yl)- tetrazoles by Sequential Assembly of Azole Fragments

Only few efficient methods for the preparation of polyazoles containing three or four nitrogen atoms in each azole cycle exist. We have developed a novel synthetic strategy that allows the sequential assembly of 1,2,3- triazole, 1,2,4- triazole, and tetrazole fragments into a new stable polyazole. Along the novel strategy, some known procedures have been optimized to achieve better conversion, selectivity, and, in general, overall efficiency.In this study, we report the Azole- Assembly Alignment (A3): a concise three step ring- forming synthesis ligates 1,2,3- triazole, 1,2,4- triazole and tetrazole to selectively give polydentate nitrogen rich ligand systems. Full analysis data of intermediates and final compounds, optimization studies and improvements of known synthetic methods are included.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/171185/1/slct202102459_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/171185/2/slct202102459-sup-0001-misc_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/171185/3/slct202102459.pd