In the reaction between salicylic acid and methanol in the presence of concentrated HCl via Fischer esterification reaction, the currently applied procedure involves the use of an excess amount of alcohol and a significant (not catalytic) amount of concentrated acid.
I performed this reaction by using a catalytic amount of concentrated acid and an excess of alcohol. In addition, I was provided the reaction mixture with a water-absorbable gel which acquired from a diaper. What you expect concerning the percentage of yield when you compare between the original procedure and my method?
Dear Abdelkader
The utilization of dean stark apparatus setup is usually results in a high yield. Unfortunately, This apparatus is not available in my Lab. Please, can provide me with another suggestion?
Regards
Hi Yasser Fakri Mustafa, to my knowledge the formation of salicylic acid methyl ester normally involves the use of small (catalytic) amounts of concentrated sulfuric acid. The use of excess methanol is also advisable, as unreacted methanol can easily be removed by distillation. The use of a water absorber could certainly be useful. In the end, the isolated yield of the ester will show you if you method is an improvement.
You can parallel start the both the method and compare the obtained yield.
I proposed the yield is improved sine the reversibility of reaction may diminish.
Dear Yasser Fakri Mustafa, did you already check out if the isolated yield of ester was higher in your case as compared to the original method?
Dear Frank T. Edelmann , yes. The percentage of yield was improved by 9%.
Dear Yasser Fakri Mustafa, great to hear that the yield could be improved. So you were right with your initial assumption! 👍
Dear all, I think it is quite wise enough to use a Dean-Starck setup for better elimination of water. I think this way you improve more the yield and also possible reaction time reduction. My Regards
Dear Abdelkader
The utilization of dean stark apparatus setup is usually results in a high yield. Unfortunately, This apparatus is not available in my Lab. Please, can provide me with another suggestion?
Regards
Hi;
The use of an excess of alcohol allows it possible to increase the speed of the reaction, because generally the concentration of the reactants as well as the temperature are kinetic factors. Methanoic anhydride or methanoyl chloride are more reactive than methanoic acid, the reaction is rapid and complete: the hydrolysis of the ester, which limits the reaction with carboxylic acids, cannot occur here.
With my best regards
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