Amine Solvents - Pyridine, Piperidine, Ethylenediamine, Morpholine, Quinoline, Diethylenetriamine, Collidine (Paperback)

Chapters: Pyridine, Piperidine, Ethylenediamine, Morpholine, Quinoline, Diethylenetriamine, Collidine. Source: Wikipedia. Pages: 34. Not illustrated. Free updates online. Purchase includes a free trial membership in the publisher's book club where you can select from more than a million books without charge. Excerpt: -41.6 C, 232 K, -43 F Pyridine is a simple aromatic heterocyclic organic compound with the chemical formula C5H5N. It is structurally related to benzene, with one CH group replaced by a nitrogen atom. It is used as a precursor to agrochemicals and pharmaceuticals, and is also an important solvent and reagent. It is a colorless liquid with a distinctive, unpleasant fish-like odor. The pyridine ring occurs in many important compounds, including nicotinamides. Pyridine was originally industrial produced by extraction from coal tar. It is currently synthesized from formaldehyde, ammonia, and acetaldehyde: CH2O + NH3 + 2 CH3CHO C5H5N + 3 H2O + H2This process (Chichibabin pyridine synthesis) involves the intermediacy of acrolein. An estimated 26,000 tons were produced worldwide in 1989. Condensations of ammonia sources and related unsaturated carbon sources affords alkyl- and aryl-substituted pyridines, e.g. monomethyl compounds (picolines), dimethyl compounds (lutidines), and trimethyl derivatives (collidines). Pyridine occurs in numerous plants, although this can mostly recorded just by smell. Goris and Larsonneau did show definite evidence of its presence in belladonna leaves, while Kuhn and Schafer of its presence in the roots of the same plant. For specialized applications, the synthesis of the pyridine skeleton is well developed. The Hantzsch pyridine synthesis, for example, is a multicomponent reaction involving formaldehyde, a keto-ester and a nitrogen donor. The Krohnke pyridine synthesis involves the condensation of 1,5-diketones with ammonium acetate in acetic acid followed by oxidation. The Ciamician-Denn...More: http: //booksllc.net/?id=23863