26266-70-6Relevant articles and documents
Chemistry of ketoacetals: II. β,β′-Ketodiacetal and β,β′-hydroxydiacetals in reactions with amminia and amines
Kharitonova,Panin,Belova
, p. 1113 - 1115 (2007/10/03)
β,β′-Ketodiacetal and β,β′-hydroxydiacetals react with ammonium acetate in acetic acid to afford substituted pyridine, and with aromatic amines in the presence of hydrochloric acid form substituted pentamethine salts. 2005 Pleiades Publishing, Inc.
Equilibration of N-(2-cyanoethyl)pyridinium cations with substituted pyridines and acrylonitrile. A change in rate-determining step in an E1cb reaction
Bunting, John W.,Toth, Andrea,Heo, Christina K. M.,Moors, Rodney G.
, p. 8878 - 8885 (2007/10/02)
The rates of equilibration of N-(2-cyanoethyl)pyridinium cations (1) with the corresponding pyridines and acrylonitrile have been measured in aqueous solutions of ionic strength 0.1 at 25 °C. Second-order rate constants (kOH) have been obtained for the hydroxide ion catalyzed elimination reactions of 16 ring-substituted 1 having pyridine leaving groups of pKBH in the range 1.5-9.7. Bronsted plots of log kOH vs pKBH are "concave down" with two distinct linear regions having β1g = -0.30 (for pKBH 1g = -0.93 (for pKBH > 5.8). This observation is consistent with a change in rate-determining step within an E1cb reaction mechanism from rate-determining deprotonation of 1 (i.e., (E1cb)irrev) for pKBH rev) for pKBH > 5.8. This interpretation is supported by 1H NMR spectral observations in basic D2O, which show no incorporation of deuterium into the acrylonitrile product for pKBH BH > 5.8. Rates of nucleophilic attack of pyridines and pyridinone anions (pKBH > 6) upon acrylonitrile have also been measured. These display a linear Br?nsted plot of βnuc = 0.20. Combination of β1g and βnuc gives βeq = 0.13 for the Michael-type addition of pyridinium cations to acrylonitrile to produce 1. Although the rates of the addition of pyridines of pKBH nuc = 0.20 for pyridines of pKBH > 5.8 to rate-determining protonation of the carbanionic intermediate with βnuc = 0.83 for pyridine nucleophiles of pKBH irrev region but is extremely weak under the current experimental conditions.
The Photo-initiated Substitution Reaction of 4-Chloropyridine and the Related 1-(4'-Pyridyl)-4-pyridone with Benzophenone in Aqueous 2-Propanol
Cosgrove, John P.,Vittimberga, Bruno M.
, p. 1277 - 1280 (2007/10/02)
4-Chloropyridine (1) converts to 1-(4'-pyridyl)-4-pyridone (4) in aqueous 2-propanol.The photo-initiated reaction of both of these compounds in acidic and non-acidic 4:1 2-propanol/water with and without benzophenone is reported.
