My aminopyridine contain cyano group close to amine group I used glacial acetic acid as catalyst nd amine was reacted with benzaldehyde in ethanol . Amine was insoluble in ethanol at room temperature but soluble in ethanol at boiling temperature. But schiff base did not form
Dear Omkar, from the literature, your product can be obtained by refluxing aminopyridine with benzaldehyde in toluene in the presence of 4Å molecular sieves (to remove H2O). See the attachment for the references.
Thank you sir , Is there any other way to synthesize this ?? In our college laboratory molecular sieves are nt present.
Alternetively, I can think of using Dean-Stark condenser to remove water.
I tried the reaction in dmf, DMSO , diclorethane. Ethanol with few drops of dmf
How about celite or silica gel? Maybe a tube with Calcium chloride to bind water from vapor during reflux in toluene?
If I understand it right, the problem with the reaction is that cyano group is in ortho- position to amino group and creating steric hindrance and withdrawing electron density from ring and amino group therefore decreasing its basicity, which is what you need for this reaction. This makes reaction quite reversible. To fight it, you need to make reaction irreversible by binding or removing water, which is byproduct of this reaction.
My structure contains Pyridine ring at 2 nd position NH2 group at third cyano and at 4 th and 6th position Der is benzene rings . schiff's base is difficult to form .
Try Solvent and catalyst free synthesis
This method works without solvent and catalyst The reaction mixture is grindedin a mortar with a pestle and progress of the reaction is monitored by column chromatography and TLC .Literature reports reveal that such reactions complete within 2-3 minute.
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