The ionic hydrogen bond. 1. Sterically hindered bonds. Solvation and clustering of protonated amines and pyridines
作者:Michael Meot-Ner、L. Wayne Sieck
DOI:10.1021/ja00348a005
日期:1983.5
2,6-dialkylpyridines, and tertiary amines were investigated in the gas phase in the absence of solvent effects. Steric hindrance causes major entropy effects unfavorable to dimerization or hydration. As long as a single confirmation exists in which the hydrogenbond can obtain optimal geometry, the bond strength is not weakened by steric crowding. However, steric crowding may result in major entropy
Process for substituting and dequaternizing pyridylethyl quaternary
申请人:Reilly Tar & Chemical Corporation
公开号:US04158093A1
公开(公告)日:1979-06-12
A process for dequaternizing a 2-(2-pyridyl)ethyl or 2-(4-pyridyl)ethyl quaternary salt of a pyridine or bipyridine base comprising the step of heating or reacting the pyridylethyl quaternary salt with a caustic material such as sodium hydroxide. Also included is a process for preparing a second pyridine base (or a bipyridine base) in which a first pyridine base is initially selected and its 2-(2-pyridyl)ethyl or 2-(4-pyridyl)ethyl quaternary salt or its acid salt prepared. An electrophilic, nucleophilic or coupling reaction can then be performed on the quaternary salt to change the substituent or to form the bipyridyl coupling and the resultant salt dequaternized with a caustic material, such as sodium hydroxide, to produce a second pyridine or a bipyridine base.