5960-22-5Relevant academic research and scientific papers
KINETICS OF FORMATION OF SOME NEW HETEROCYCLIC AZOMETHINES DERIVED FROM NITROSO AND ACTIVE METHYL COMPOUNDS
Mahmoud, Mohamed Rafat,El-Samahy, Ahmed Abdalla,Hamed, Maher Mohamed Ahmed,Shaker, Ali Mohamed
, p. 217 - 222 (2007/10/02)
The kinetics of base-catalysed condensation of active methyl heterocyclic quaternary salts with some nitroso derivatives in methanol have been investigated.In the presence of piperidine, the reaction was found to follow pseudo-second-order kinetics, being first order with respect to each of the reactants.It is suggested that dehydration of the carbinolamine intermediate is the rate determining step.This is supported by the observation that the reaction rate increases as the electron releasing power of the substituent attached to the nitroso aromatic ring is increased or as the electron withdrawing power of the heterocyclic moiety attached to the active methyl group is increased.Furthermore, it is concluded that the tendency of the hydroxylic solvent employed as a reaction medium to associate through hydrogen bonding plays an important role in the condensation rate.
Electronic absorption spectra of some new heterocyclic azomethines derived from nitroso and active methyl compounds
Mahmoud, M. R.,Awad, A. M.,Shaker, A. M.
, p. 1177 - 1184 (2007/10/02)
The electronic spectra of some new heterocyclic azomethines derived from nitroso compounds and active methyl heterocyclic quaternary salts were studied.The main visible band appearing in the spectra of dialkylamino derivatives is assigned to an intramolecular charge transfer (CT) transition.On the other hand the visible spectra of o-hydroxy compounds are interpreted on the principle of the possible existence of such compounds in a enol keto tautomeric equilibrium.In addition the pKa values of these compounds were determined and discussed in terms of molecular structure.
