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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. Hence they are stronger acids than ...
Hantzsch pyridine synthesis with acetoacetate, formaldehyde and ammonium acetate, and iron(III) chloride as the oxidizer. The contemporary methods of pyridine production had a low yield, and the increasing demand for the new compound urged to search for more efficient routes.
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.
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 ...
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.
Collins reagent is a solution of the same CrO 3 (pyridine) 2 but in dichloromethane. The Ratcliffe variant of Collins reagent relates to details of the preparation of this solution, i.e., the addition of chromium trioxide to a solution of pyridine in methylene chloride. [3]
2-Chloropyridine is an aryl chloride with the formula C 5 H 4 ClN. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry. It is a colorless liquid that is mainly used to generate fungicides and insecticides in industry.
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]