Dear Mahrokh Moradi

Purifying a compound with both acid chloride and chloroformate functional groups can be tricky due to their reactivity, especially with moisture and heat. To purify your product containing acid chloride and chloroformate groups without degradation:

These steps should help you purify your product while avoiding degradation.

Thanks.

Thank you so much for your fast response. But I did the vacuum distillation and cold finger technique, but it did not work. For recrystallization, you mentioned the pairs of water-methanol, but acid chloride will undergo hydrolysis with water, isn't it? And we cannot use column chromatography since the acid chloride will be exposed to the air. And in the case of Low-Temperature Evaporation, my problem is not to remove the solvent because I can remove the solvent under the vacuum using the Shelenk line. So, I was wondering if you could help me with other ideas. Many thanks

I would try a high-vacuum distillation. If you only have a small amount a Kugelrohr - see Wikipedia might be your best bet.

Crystallisation: could try Methyl acetate/ Hexane (dried). Otherwise its making sure the precursor is clean, convert to the active chlorides and use crude.

@duncan Judd, Can you please clarify what you mean by making sure the precursor is clean, converting it to active chlorides, and using crude? I am confused by this part.

@ Duncan judd . Thanks for clarification. The precursor that I used to make this molecule is pure. Actually, since I will use this molecule as my monomer and I can polymerize it with diol, I need to purify it otherwise I won't get the high molecular weight of my desired polymer.

Even if you do manage to get the monomer 99% pure, one in a hundred molecules will be likely to terminate the chain, so I don't think you're likely to get high-MW polymers using acyl chloride chemistry.

A condensation polymerization of the carbonate-containing dimer would be a better approach. (This is how polyesters are made commercially, and there are quite a few ways to go about it.)

@ james, Thanks for your response. But since I use the diol, it reacts with acyl chloride and turns it into polyester. The problem is not the termination the problem is that for condensation polymerization ( step polymerization) we do need to have the pure monomer.

If it is an acidic substance, have you considered adding a base to form a salt before separating it? Or use methods such as recrystallization to purify the substance.

@ Chen jingwen Since my molecule has acid chloride and is very reactive, I do not know if recrystallization works. I will give it a try. Which solvent system do you recommend for recrystallization?