[petsensor]

I was trying to prepare a schiff base by using 2,6-dibromo-4-aminopyridine and 9-anthraldehyde and failed several times. The conditions by which I ran the reation including:
1. refluxing the two SMs in EtOH/ MeOH with/without acid catalyst such as tosylic acid;
2. Dean-stark conditions with/without the acid catalyst in toluene/benzene;
3. Refluxing the two SMs in toluene with drying reagent like molecular sieves or MgSO4.

I am wondering if anyone ever had some experience on Schiff bases and can give me some advice. Thanks a lot.

[carl_pitt]

dear sir
you must to use 1-butanol or higher alcohol with higher boilig point like hexanol or cyclohexanol as solvent insteed ethanol and then :
put your aldehyde with your solvent in a round-bottum and begin to reflux them. add your amine dropwise in 20 minutes.need time for reflux is about 4 till 10 hours at boiling point. there's  no need to acid .but you can do it if you want .all you need is high temprature and dry condotion.

[HP]

You may try also to convert your aldehyde in  acetal for example with exess  ethanol/HCl or may be with triethylformiate(i am not sure if it work for this aim) and after that to try condensation of the anthranyl acetal with the amine best in aprotic solvent as benzene or toluene in reflux. If  this reaction proceed you could understand by the eliminating in the reaction ethanol...

[laotree]

Standard T(OiPr)4 or other Ti(OR)4 as de-water reagent!

Good luck!