From: Jacob Zabicky (Jacob.Zabicky$##$uab.es)
Date: Tue Jun 20 2000 - 09:23:39 EDT
Hello Kamil,
Just a few comments that may be helpful to solve your problem. First,
absolute dryness of the solvent has to be assured. Schiff base formation is
a reversible process, so it's advisable to somehow remove the water
produced during yhe carbonyl-amino condensation. Weah basic catalysis to
the hydrolysiscan be provided by the imine or residuals of
o-phenylenediamine, whilst weak acid catalysis can stem from the phenolic
hydroxy groups.
Jacob
>Hello, I have some problems with salophenes (Schiff bases). The problem
>is as follows: the synthesis of salophene from salicylaldehyde and
>o-phenylenediamine is performed in MeOH/CH2Cl2. But once synthesised,
>when dissolved in CH2Cl2 seems to be not stable. UV/VIS spectra confirm
>that in CH2Cl2 solution the peaks from salicyaldehyde appears. That may
>indicate decomposition of salophene. But is it possible that so
>"neutral" solvent as dichloromethane is able to destroy the imine
> bonds ?
>Thank you in advance
>--
>Kamil Wojciechowski, Ph.D. student
>Department of Analytical Chemistry,
>Warsaw University of Technology,
>Noakowskiego 3, 00-664 Warsaw, Poland.
>Tel.: 0-22-660-56-31
> e-mail: kamilwoj$##$ch.pw.edu.pl
> kamilwoj$##$chemix.ch.pw.edu.pl
> http://www.ch.pw.edu.pl/~kamilwoj/index.html
>
>
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