Reflux alcoholic solution of 5-substituted 3-amino1,2,4-triazole with benzaldehyde or 4-chloro benzaldehyde using acidic catalyst (glacial acetic acid or HCl or H2SO4) for 12 hours not give any product. Also when basic catalyst (KOH) used no product formed.
Is There Any Explanation for This Result And how Can I Make Schiff Base From 5-substituted 3-amino1,2,4-triazole ?
You need to activate formyl group of aldehyde. For inspiration see https://www.researchgate.net/publication/267390365_Comparative_Studies_of_Catalytic_Application_of_Cerium%28III%29_Chloride_and_Resin_Supported_Cerium%28III%29_in_Domino_Syntheses_of_15-Benzodiazepine_and_13-Diazine_Skeletons
Pleas inform me about results. Thanks.
Article Comparative Studies of Catalytic Application of Cerium(III) ...
Schiff base derivative from 5-substituted 3-amino1,2,4-triazole is prepared by reacting equimolar mixture of 2-amino 1,2,4-triazole with benzaldehyde in alcohol in presence of acid or base catalyst. The acid catalyst acetic acid can be used,. After heating mix. gently for 1-2 hrs , the mixture is concentrated to get solid Schiff,s base.
You can prepare by the reaction of 2-amino 1,2,4-triazole and benzaldehyde (equimola ratio) in alcohol, reflux it for 7-8 h. add 1-2 drops of AcOH. Check the progress of the reaction by TLC. You will get the product.
Sorry, bad reference above. Right is https://www.researchgate.net/publication/265959505_Synergism_of_Metal_and_Organocatalysis_in_Condensation_Reactions_of_Aromatic_Aldehydes_with_Anilines_Affording_Imines_Effect_of_Catalysts_on_the_Base_of_a_Supported_Cerium%28III%29_and_Proline. Under described condition low reactive aldehydes and low reactive amines react very good
Article Synergism of Metal and Organocatalysis in Condensation React...
Thank you all for your answers but im working on 3-amino1,2,4-triazole not 2-amino1,2,4-triazole.Also, when i added glacial acetic acid as catalyst the PH of the reaction remains neutral it never get acidic.
IS there any explanation for this?
Try using minimum amount of absolute ethanol as solvent, add an equimolar ratio of aldehydes then add few drops of H2SO4 98%. Heat under refluxe and monitor the reaction by TLC (eluent benzene:ethyl acetate 1:1 v/v)
Ionut ledeti
i tried using H2SO4 and no reaction happens (No new spot on TLC just starting triazole and aldehyde )
I have 6-bromo 1,8-naphthyridine 4-one on 5 position
i also had a lot of problems when trying to prepare schiff bases derived from functionalised 4-amino-1,2,4-triazoles. no literature indication seemed to work for me. however, i tried this, with succes: 0.001 mol aminotriazole dissolved at room temp in 15 mL absolute ethanol, then 0.001 mol aldehyde was dissolved in the prepared solution. the mixture was cooled on ice bath under 5C and 1 mL of concd. H2SO4 was added. the suspension was stirred for 10h then filtered of.
(see paper Synthesis and Degradation of Schiff Bases Containing Heterocyclic Pharmacophore, on my profile). try and maybe it will work
i tryied 9 different pathways mentioned in literature and none of them led to Schiff base, but this one.
Thank you very much lonute ledeti
I will try it but the starting triazole not soluble in ethanol at room temperature should I heat to dissolve or proceed the reaction with insoluble triazole?
Try to find then a solvent where the triazole is soluble. What did u used for sample preparation for the TLC analysis?
Schiff base reactions are equilibrium reactions. The way to get it to converge to the product is to remove the water which forms as a byproduct of the reaction. To do this, simply add some MgSO4 (anhydrous) to the reaction mixture, then filter afterwards. Alternatively use a so-called Dean-Stark apparatus which collects the water during the reaction. The problem is definitely the water... remove it and the reaction will work :-)
as Burgert said you can use Dean-Stark apparatus and heat the mixture to about 80 and add few drop from acetic acid
hi Noha.... i have same problem as you.... too make worse.... my compound also could not dissolve in methanol or ethanol under reflux. did you found solution for your problem??
Hi Elmi ..... yes i found a solution for my problem..... My Triazole is not strong nucleophile thats why it was difficult to react i dont know the nucleophilicity of your comound but Try this:
FIrst use predistilled Methanol or HPLC grade
Second Try to use few drops of conc HCl if no reaction use Conc sulforic
Third drying agent like MgSo4 or CaCl2
if Your compund is partially souable it will react giving product and more will dissolve
Noha.... did you reflux your reaction? Can i add just add mgso4 or cacl2 if the reaction under reflux condition?
You can prepare make schiff base derivative from 5-substituted 3-amino1,2,4-triazole by reacting it with aryl aldehyde in ethanol under warming with continuous stirring adding 2-3 drops of Acetic acid. On cooling in ice bath Schiff's bases separate out..
Schiff base derivatives of 5-substituted 3-amino1,2,4-triazole can be prepared by reacting the said compound with aryl aldehyde under microwave irradiation or by ultrasound method by heating the mixture in ethanol in presence of acetic acid for 3 hrs. & concentrating& cooling the reaction mixture , Schiff,s base separates out.
Elmi
I had to reflux the reaction and use a catalyst like acetic acid or sulforic because the nucleophilicity of the amino group in this position is not strong enough to react without catalyst
i dont know the nucleophilic charcter of your amine if it is strong then use MgSO4 alone if not you have to use acetic acid or another catalyst