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The Mechanism of Schiff Base Formation of Some Arylidenes‐ p ‐Aminosalicylic Acid
Author(s) -
Adam F. A.,
ElHaty M. T.,
Ibrahem A. A.
Publication year - 1984
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.198400049
Subject(s) - chemistry , piperidine , aldehyde , schiff base , reaction rate , reaction rate constant , medicinal chemistry , order of reaction , amine gas treating , reaction mechanism , base (topology) , organic chemistry , catalysis , polymer chemistry , kinetics , mathematical analysis , physics , mathematics , quantum mechanics
Formation of a series of Schiff bases derived from p ‐aminosalicylic acid I and various aromatic aldehydes has been studied kinetically in ethanol medium in presence of piperidine as a basic catalyst. The order of the reaction is determined to each reactant by following the concentration of the Schiff base formed during the reaction. The reaction is Kinetically third‐order in the presence of low concentration of piperidine, first‐order to each of I , aldehyde and piperidine. On the other hand, in presence of ≥5×10 −4 M of piperidine the order of the reaction changed to second‐order, thus much the reaction is independent of piperidine concentration. The rate determining step is suggested to be the dehydration of the carbinolamine intermediate step 4. Variation in reaction rate constants with the different substituent of the aromatic aldehyde, with substituents of aromatic amine and with the nature of the hydroxylic organic solvents as reaction medium are studied and discussed.