What is your desired product? mono or bis acetyled?

Bis acetyled.

If bis product, why not use excess acyl chloride?

Since we didn't get our desired acetyled product and got multiple byproducts, we wish to do schiff base reaction with PPD to get imine.

What acetylation conditions are you using? Use of acetyl chloride + organic base or acetic anhydride in pyridine are the most common.

You should check the purity of p-phenylenediamine, it can be oxidised if not kept properly.

Reductive animation conditions can be readily found, but the problem may lie with the compound itself.

We did acetylation with acetic acid and acetic anhydride.

Thanks for your suggestion sir.

add organic base ( TEA or pyridine or..) is very important, since acetylation will form HCl(using acetyl chloride) or acetic acid (using acetic anhydride), HCl or acetic acid will form salt with your SM, the salt will not react.

Ok sir. Thank you so much for your answers.

follow.....................................................................

Ok sir,..

Use as starting material 4-nitroaniline.After acetylation by acetic anhydride with trace of sulfuric acid hydrogenate the resulting product. You should get high purity p-phenylenediamine monoacetate.

ThanK you sir...