Pharmacist

Schiff base

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Good day, 

I hope you answer my question. 

1.

I am trying to synthsis schiff base, should I dissolve my reactants? 

Because they are not totally be dissolved even in hot solvent" ethanol"

 

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27 minutes ago, Pharmacist said:

Good day, 

I hope you answer my question. 

1.

I am trying to synthsis schiff base, should I dissolve my reactants? 

Because they are not totally be dissolved even in hot solvent" ethanol"

 

I think it kinda depends upon your reactants.

You need a solution for the formation of the intermediate iminium ion.

 

imines1.jpg.98026e5f6cca5b26b36886f115b73f87.jpg

 

When you are looking at the literature the modern term for Schiff Base is imine.

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Just because they aren’t dissolved doesn’t mean you aren’t getting reaction. Have you checked that you are getting product formation? 

Beyond that, the obvious solution is to change solvents and think of additives. There are plenty of options available, so I would look up literature on your compound if it’s available. If not, do you know what your compounds are soluble in? You can try solvents like methanol or maybe THF, or spiking in small amounts of DMF / DMSO until everything solubilises. You can also add small amounts of acetic acid or similar to help drive everything. 

 

4 hours ago, studiot said:

I think it kinda depends upon your reactants.

You need a solution for the formation of the intermediate iminium ion.

 

imines1.jpg.98026e5f6cca5b26b36886f115b73f87.jpg

 

When you are looking at the literature the modern term for Schiff Base is imine.

Schiff bases are not usually made under basic conditions due to competing reactions, although it is possible. It’s typically done with small amounts of acid. Schiff base is also still a fairly common term, so it shouldn’t be too hard to find by looking up either. That being said, the best way to search literature on these things is structure based searches through SciFinder or similar.

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5 hours ago, studiot said:

I think it kinda depends upon your reactants.

You need a solution for the formation of the intermediate iminium ion.

 

imines1.jpg.98026e5f6cca5b26b36886f115b73f87.jpg

 

When you are looking at the literature the modern term for Schiff Base is imine.

 

My reactants are dioxane, CH2Cl2 and CHCl3 soluble. 

I have tried dioxane and ethanolwith different ratios

Also I have tried ethanol and minimal CHCl3. 

On TLC all reactant appeared and no obvious new spot. 

I think my low yield schiff base is being hydrolysed on TLC "aliminium oxide" 

I will try CH2CL2 WITH Mgso4 and glacial a.a

 

If not succeed, I will try dean stark trap with toluene although the reactants aren't soluble in it. 

 

My reactants are dioxane, CH2Cl2 and CHCl3 soluble. 

I have tried dioxane and ethanolwith different ratios

Also I have tried ethanol and minimal CHCl3. 

On TLC all reactant appeared and no obvious new spot. 

I think my  schiff base is being hydrolysed on TLC "aliminium oxide" 

I will try CH2CL2 WITH Mgso4 and glacial a.a

 

If not succeed, I will try dean stark trap with toluene although the reactants aren't soluble in it. 

IMG_20181129_195840.jpg

Edited by Pharmacist
I hane set wrong photo

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