Search results
Results from the WOW.Com Content Network
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−). It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell.
The direct amination of pyridine with sodium amide can take place in liquid ammonia or an aprotic solvent such as xylene is commonly used. Following the addition elimination mechanism first a nucleophilic NH 2 − is added while a hydride (H − ) is leaving.
Demethylation often refers to cleavage of ethers, especially aryl ethers. [12]Historically, aryl methyl ethers, including natural products such as codeine (O-methylmorphine), have been demethylated by heating the substance in molten pyridine hydrochloride (melting point 144 °C (291 °F)) at 180 to 220 °C (356 to 428 °F), sometimes with excess hydrogen chloride, in a process known as the ...
Direct halogenation of pyridine with chlorine gas above 270 °C gives a mixture of 2-chloropyridine and 2,6-dichloropyridine. [1] 2- and 4-chloropyridine are prepared from the corresponding pyridinols using phosphoryl chloride. [1]
20 Quick Dinners You Can Make With Eggs. 15 Quick and Easy Breakfast Egg Recipes Ready in 15 Minutes or Less. Read the original article on ALLRECIPES. Related articles. AOL.
Pyridine reacts with HCl produced forming the THF insoluble pyridine hydrochloride salt. Water is then added to the solution to dissolve the precipitated pyridine HCl and decrease the solubility of the MCPO in solution, causing it to precipitate. The MCPO precipitate is then filtered and washed with water to remove contaminants.