This is a blog created by Ms Luminati (science teacher), Ms Mathis (English teacher) and Ms Burguière (science teacher) for the students of lycée expérimental André Malraux (Biarritz, France) who are learning science in English. They want to show that science is fun, interesting and easy particularly when it is done in English!
This year we hope to work again with some fine European partners.
Let us all have fun together!
Monday, 12 March 2018
In what consist our project ?
Our project consist to improve the paracetamol synthesis. In fact, we want to improve the yield of the synthesis,while respecting principles of the green chemistry.
Why did we choose to do this project ?
We wanted to work on it because it's one of the pharmaceuticals the most sold in the world : it was interesting to try to improve it synthesis.
In what consist the reaction ?
We make react para-aminophenolwith acetic anhydride to produce paracetamol and acetic acid
The acetic acid is filtered at the end of the synthesis
How did we try to improve it ?
We had to change the reagent's moles to have the best yield possible :
We've first did a synthesis with anhydride acetic in default : the yield was about 17 %
The second one was a synthesis with para-aminophenol in default : the yield was about 50%
And the last experiment was a synthesis with both equals : the yield was about 72%
the yield went from 17% to 72%
Our paracetamol :
On the other hand, we had to replace a reagent by another : replace acetic anhydride by acetyl chloride.
We met few problems with this one : it can't be in contact with water. So the para-aminophenol can't be dissolved in it.
Then, we tried to dissolve it in another solvant, the DMSO, because it's a polar molecule, as the para-aminophenol. (We dissolve a polar molecule in a polar solvant).
But the DMSO also react with the acetyl chloride, and may make another product that is called : Swern reagent.
Then we conclued that we can't improve the paracetamol synthesis if it's not by changing reagent's moles with our knowledge.
What kind of problems have we met ?
We had a lot of problems by making paracetamol : in fact, the reagents we use are very dangerous :
some of them have toxic fumes, can be corrosive, or can explode by a contact with water !
Then, we had to be careful while carrying out the experiments, and wear lab gloves, lab glasses and a lab coat.