Conversion of acid chlorides to esters through addition of an alcohol

by James

Description: Acid chlorides are converted to esters when treated with alcohols.

Notes: Base is sometimes added to neutralize the HCl that is formed in this reaction.



The third example is an intramolecular reaction – make sure you can see this.


1,2-addition of alcohol to the acid chloride (Step 1, arrows A and B) results in an anion, which is then protonated (Step 2, arrows C and D). Elimination of chloride ion (Step 3, arrows D and F) results in a positively charged ester, which is then deprotonated (Step 4, arrows G and H).


  • The reaction is considerably faster when base is added to remove the HCl that is formed.
  •  There are other reasonable ways to show the proton transfer and deprotonation steps.


{ 2 comments… read them below or add one }


do you have a mechanism explain the reaction between alcoholic alkoxide with acyl halide or anhydride to form ester ??
I’m interested in to make a reaction between alcohol and maleic anhydride , but i don’t know what is the mechanism of the reaction will occur ..
may you help me please ??

Thanks ,



James Ashenhurst

It’s the same as this, but there is no proton transfer step. Addition and then elimination.


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