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Pyridinium perbromide (also called pyridinium bromide perbromide, pyridine hydrobromide perbromide, or pyridinium tribromide) is an organic chemical composed of a pyridinium cation and a tribromide anion. It can also be considered as a complex containing pyridinium bromide—the salt of pyridine and hydrogen bromide—with an added bromine (Br ...
Pyridinium refers to the cation [C 5 H 5 NH] +. It is the conjugate acid of pyridine . Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines.
In organic synthesis, PPTS is used as a weakly acidic catalyst, providing an organic soluble source of pyridinium (C 5 H 5 NH +) ions.For example, PPTS is used to deprotect silyl ethers or tetrahydropyranyl ethers when a substrate is unstable to stronger acid catalysts.
The reaction of pyridine with bromomethyl ketones gives the related pyridinium salt, wherein the methylene group is highly acidic. This species undergoes a Michael-like addition to α,β-unsaturated carbonyls in the presence of ammonium acetate to undergo ring closure and formation of the targeted substituted pyridine as well as pyridinium ...
PubChem is a database of chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information (NCBI), a component of the National Library of Medicine , which is part of the United States National Institutes of Health (NIH).
Pyridinium chlorochromate in a vial. Pyridinium chlorochromate (PCC) is a yellow-orange salt with the formula [C 5 H 5 NH] + [CrO 3 Cl] −. It is a reagent in organic synthesis used primarily for oxidation of alcohols to form carbonyls. A variety of related compounds are known with similar reactivity.
Brequinar has been investigated as an immunosuppressant for preventing rejection after organ transplant and also as an anti-cancer drug, but was not accepted for medical use in either application largely due to its narrow therapeutic dose range and severe side effects when dosed inappropriately.
The pyridinium side-group of cephaloridine has unstable bonds to the core of the compound (in comparison with other cephalosporins). When this side-group leaves, the β-lactam ring is destabilized by intramolecular electron shifts. [13] Thus, the leaving group creates a reactive product.