138965-40-9Relevant academic research and scientific papers
Mechanism of Carboxylic Acid-Catalyzed Reduction of Substituted Nitrosobenzenes by 1-Benzyl-3,5-bis(1-pyrrolidinylcarbonyl)-1,4-dihydropyridine in Acetonitrile
Awano, Hiroshi,Tagaki, Waichiro
, p. 3117 - 3124 (1986)
Mechanism of carboxylic acid-catalyzed reduction of substituted nitrosobenzenes by 1-benzyl-3,5-bis(1-pyrrolidinylcarbonyl)-1,4-dihydropyridine has been studied in acetonitrile at 25 deg C.The major product was hydroxylamine when the dihydropyridine was used in excess over nitrosobenzene, while that was azoxybenzene in the reverse case.The observed second-order rate constant kR2 are dependent on acid concentration in a first-order manner with the acid-catalyzed third-order rate constant kRH.The Hammett relationship for kRH for substituted nitrosobenzenes gave a ρ=-0.93.The Broensted plot of log kRH vs. pKa of acids gave a straight line with a slope of -0.34.The deuterium isotope effect for the catalysis by dichloroacetic acid was found to be kRH/kRD=2.80.These results indicate that a general acid catalysis by carboxylic acids plays an important role in the reduction of nitrosobenzene by dihydropyridine in acetonitrile.
metal-ion-facilitated Oxidations of Dihydropyridines with Molecular Oxygen and Hydrogen Peroxide
Tamagaki, Seizo,Mimura, Takashi,Tagaki, Waichiro
, p. 1645 - 1650 (2007/10/02)
Some bivalent metal ions such as alkaline-earth metal ions promoted the O2- and H2O2-oxidations of 3,5-disubstituted 1,4-dihydropyridines in acetonitrile; particularly, in presence of Ca2+ in excess over the dihydropyridines completed these rea
