Phenacetin are nonopioid analgesics drug which was used as a pain-relieving and fever-reducing drug.
Today’s spectacle is deal about synthesis of finasteen so how can we synthesize financing it is very simple you guys are know about the paracetamol this is structure of paracetamol and the further reaction of paracetamol we will get financing so let’s start with that uh synthesis of financing first we will check the background the paracetamol known as acetophene
And finasterine are non optoid analgesic both are depicted in a figure one this is both the structures difference is only the oh and oc2 c2h5 acetaminophen was synthesized in 1877 and first used in in humans in 1887 by the german centered by the german company bayer and it was principally used analgesic drug so financing is a acetophenyline and for ethoxy phenyl
Acetamide is widely used as a pain relieving or fever reducing drug it is a most widely used non-anti-inflammatory medicine to moderate pain relief and favor reduction so that is financing analogous to acetaminophen was utilized for a hundred years ago it is some history of that one it is used like although it is very effective as a non-optoid analgesic physician
And the fda had concerned with this carcinogenic properties as well as its negative effect on the kidneys so financially in allergistic effects are due to its action of sensory tract of spinal cord in addition financing has depressed action on a heart will act as a negative ionotrope it is antibiotic acting the brain to decrease the temperature set point and
Is also used to treat rheumatoid arthritis and intercostal neuralgia so it is also used for that kind of disease now we are a little bit discussed about the principle of the financing so the principle is deal with that acetophene will be accomplished via williamson’s ether synthesis it will be synthesized by williamson ether synthesis this is a reaction between
The alkoxide or phenoxide with methyl or primary alkyl halide the ethoxide reacting with methyl iodide to yield compound ethyl methyl ether so like that this is a ethoxide with methyl iodide in the presence of some solvent yield methyl ethyl ether that is methyl ethyl ether the requirement of this one is acetaminophen k2co3 methyl ethyl ketone and ethyl iodide
Particularly for the mole ratio like here the all mole ratio is given for you so now we’ll take a mole ratio for that one so here we take a is a b c d e f g h i j that is q r and s so now we will switch to the first get a q but before that we will take a moles of acetaminophen so how we take c is equal to 3.0 divided by 151.16 and for that we will get 0.019
The mole of acetaminophen so that’s the mole of acetaminophen if you want to carry it out or if you want the mole of k2co3 then the formula q is equal to c into f into e we will get the exact gram of the k2co3 which is 3.977 another one is r so how we get the r the same c into g into h is equal to 46.19 gram of methyl ethyl ketone but it had density 1.1 so
Is 42 ml and then s c into i into j is equal to 7.55 gram divided by density 1.98 then we will get 3.81 ml so that is the the queue is the weighing of that k2co3 how much amount you take 97 grams approx 4 gram here is equal to 42 ml and here is equal to 3.81 ml so that you have taken for the synthesis so in next step we will discuss about the reaction is
When acid aminophene or parasita mole reacted with methyl ethyl or isomethyl iodide then it will be converted to phenocetine and how it will becomes and how it will convert let me see in the next mechanism portion so the mechanism if we add k2co3 to that paracetamol it will abstract the proton base always after the proton and form an ion that anion attacks to
That ethyl iodide and after attacking the ethyl iodide we will get that kind of intermediate compound where i also attached to it when the negative then the density of carbon is increased so it will be try to remove the iodine to fulfill that valency and after the transfer the whole the balance in charges we will get our compound finacetin that is our compound
With cs2 ch3 so that is our mechanism the third one is procedure so the procedure is first of all you take 2 gram of acetaminophen weighing 2.65 gram of t2co3 add methyl ethyl ketone 27 ml to 100 ml rbf adithya iodide point 64 ml wire series followed by the magnetic stirrer on hot plate turn the stirrer on low flame the starch bar should be allowed to spin at
A rate of sufficient mixture the heterogeneous solution and note that the k2c3 will be not dissolved in solution so k2co3 is remain undissolved in the solution so don’t not try to dissolve it attach the condenser reflux for one hour then after one hour finished reduce the heat 50 degree and let the rbf cool to the touch then add 10 ml of water into the rbf use
Then separating funnel using separate funnel just try to get the bag the organic layer extract the organic layer with five percent water nano edge add two times 16 ml of water again wash with brine dry that organic layer with cacl2 till 5 minutes and then decant the cscl2 you’ve applied the solvent isolate the product obtain ir nmr for the product and starting
As a terminal fee so next we will discuss about the calculation in the calculation portion the starting material or the starting reagent is paracetamol so the molecular formula molecular formula both starting and the product is here the molecular weight of paracetamol is 151 point 16 gram per mole and the molecular weight of salon is 179.22 gram per mole the
Theoretically we can calculate 151 point 16 gram paracetamol forms 179.22 gram phenoacetine so we can get b value the theoretical yield is this one the practically what we get is point nine so from the practical lead and theoretically we can get a percentage yield so practically l divided by theoretical yield is equal to something x amount so we’ll get here the
Percentage yield now it is fine till the calculation so our compound is dried and let’s try with ir spectra in the ir spectrum we look at the here there is a three three five zero centimeter inverse there is a one p the another is the here the next one is the here so we will look about that nh coch3 and oco2 c3 stretching vibration frequencies and we can write
It down here in centimeter inverse so the next graph is the mass spectrum and the mass spectrum is very easy to solve as well because here if you see there is a 178 point and 180.01 so as seen before here is a 179.22 so here about 179 point 11 so that is m plus peak and that that is m plus one peak so the mass spectrum confirms that yes there is a pre there is
A formation of pin acetone is done through the molecular weight calculation and the final step which can be identified perfectly whether that is the finances was prepared or not with the helping of nmr technique so here let’s see first that ch3 is the ending of the corner that’s h2 at the mid and next to that hydro atoms so that ca3 comes at the position here
So that is the ch3 the second which is comes if you see here that is that one ca3 because it directly attached to the c double bond o due to inductive effect it’s just slightly higher than the terminal ch3 or alkyl ch3 so that is ch3co ch3 that one co3 is here that this ch2 it feels multiplied due to that one because here three hydrogen is three plus one four
So it’s multiplied it’s clearly visible here so that is ch2 which one which is next to the o so now next we will switch to the six point eighty three hydrogen so that is two hydrogen of aromatic ring that is seen a doublet of 6.83 it’s a doublet of two hydrogen this again 7.45 it is also doubling 7.45 it’s for two hydrogen and that is nh which is very high due
To that negativity of the c double bond o as well as the nitrogen element so it is nine point eighty six at one h sorry nine point eighty six for one edge and singlet that is singlet so that is all about the animal spectrum of that particular compound now what is the result table so resultable you have to filter all the details and here you have to write the
Compound which you will get from here write the group which is present and here the percentage yield what you get throughout the practical this reference from where i will get that whole information and thank you for watching
Transcribed from video
Synthesis of Phenacetine from Acetaminophen By ChemistryLive
