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Containing a pyridinium ion, pyridinium chloride has a pK a of approximately 5, slightly more acidic than that of typical amines.This is due to the hybridization of the nitrogen: the nitrogen is sp 2 hybridized and more electronegative than those nitrogens in ammonium cations, which are sp 3 hybridized.
It is the conjugate acid of pyridine. Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines. They are prepared by treating pyridine with acids. [3] As pyridine is often used as an organic base in chemical reactions, pyridinium salts are produced in many acid-base reactions.
Pyridine is a basic heterocyclic organic compound with the chemical formula C 5 H 5 N.It is structurally related to benzene, with one methine group (=CH−) replaced by a nitrogen atom (=N−).
C 5 H 5 N + HCl + CrO 3 → [C 5 H 5 NH][CrO 3 Cl] In one alternative method, formation of toxic chromyl chloride (CrO 2 Cl 2) fumes during the making of the aforementioned solution were minimized by simply changing the order of addition: a cold solution of pyridine in concentrated hydrochloric acid was added to solid chromium trioxide under ...
Phase behavior Triple point: 231.48 K (–41.67 °C), ? Pa Critical point: 619 K (346 °C), 5660 Pa Std enthalpy change of fusion, Δ fus H o: 8.28 kJ/mol Std entropy change
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.
Imidazo[1,2-a]pyridine—an example of imidazopyridine and a core structure of zolpidem and some compounds described below.. An imidazopyridine is a nitrogen containing heterocycle that is also a class of drugs that contain this same chemical substructure.
3-methyl pyridine is biodegradable, although it degrades more slowly and volatilize more readily from water samples than either 2-methyl- or 4-methyl-pyridine., [7] [8] 3-Methylpyridine is the main precursor to niacin , one of the B vitamins .