Today we isolate paracetamol (acetaminophen) from tablets using acetone.
Paracetamol is a medication used to treat pain and fever however i’m interested in it as a chemical precursor and in this video i will be extracting some from over-the-counter tablets there are already youtube videos about extracting paracetamol from tablets links to two such videos that i liked and found relevant are in the video description this looks dodgy doesn’t
It and i know you must be wondering if i have a cousin from france but no the pills on the left are a generic brand of paracetamol does i got from friends and family they are past their expiration date but will be good enough for my purposes in the beaker there are 40 tablets each tablet contains 500 milligrams of paracetamol so the total amount of paracetamol in the
Beaker is 20 grams the only other chemical needed is acetone the one i used was distilled from acetone but at a hardware store i perform the distillation just so that i could be sure there are no non-volatile contaminants in my acetone this is important because i will be evaporating the acetone and any non-volatile contaminants would remain in my isolated product
At first i thought i would only use the 150 milliliters of acetone you see in the picture but i ended up using a total of 280 milliliters of acetone which is way too much and if i was careful the 150 milliliters that i planned on using would be more than enough i didn’t crush the tablets i just put the beaker with the tablets on my magnetic stirrer and heater then
Added a stir bar and poured in 150 milliliters of acetone after this i turned on the heating and stirring as you can see at the beginning i had some problems with the stirring and off camera i had to stir the mixture for a few minutes with a glass rod until enough of the tablets dissolved so that the stir bar began to function properly after a while i got impatient
And added another 50 ml years of acetone when i no longer saw anything resembling a tablet in the mixture it is very likely that all of the paracetamol is in solution at this point the mixture reached a gentle boil but just to be extra sure that all of the percy de mal dissolve i left it stirring and boiling for another 10 minutes after this i vacuumed filtered the
Suspension wild but still boiling hot first i wetted the filter paper with a little bit of acetone and then proceeded to pour the hot suspension into the buckner family i washed the beaker and the solids in the buchner funnel with another 50 milliliters of fresh hot acetone the paracetamol that i want is dissolved in the filtrate and as you can see the product began
To crystallize in the vacuum flask what remains in the buchner funnel are the undissolved impurities after drying these solids they had a mass of 7.6 grams even after reading the product by heating the vacuum flask with a heat gun the filtrate was still slightly cloudy it would seem that a very small amount of excipient got past the filter paper as i was doing the
Vacuum filtration so i decided to filter the hot solution again this time through a small amount of cotton packed in a funnel and because this was going to be a slow process i also decided to start evaporating the acetone at the same time during the filtration i used the heat gun to keep the solution hot and prevent the paracetamol from crystallizing in the family
The evaporation proceeded quickly and even before i finished this second filtration the product was already crystallizing in the beaker after all the solution was filtered i washed the vacuum flask and the funnel with an additional 30 milliliters of fresh hot acetone i continued heating and stirring until the content of the beaker was only slightly wet with acetone
I then removed the beaker and let it stand for two days so that the last traces of acetone evaporated after two days i was left with a nice almost white crystalline powder i transferred the product into pre-weighed amber glass storage bottle i got 18 point two grams of paracetamol this represents a ninety-one percent yield okay that’s all have a nice day and see you next time
Transcribed from video
Extracting paracetamol (acetaminophen) from tablets By OrganoLeptic
