Skip to content

Phenytoin synthesis

  • by

#phenytoin #synthesis #GPAT# NIPER#PHARMACY#

Hello dear friends and dear friends our today’s topic is a medicinal compound which is called as phenytoin which is abbreviated as p h t so p h is taken from this and t is taken from this so it is ps t this is the structure for phenytoin now one important point is that this compound is used as anti epileptic drug in the treatment of tonic clonic seizure which is

Also called as grand mal epilepsy where there is the contraction of the muscles and secondly it is used in the treatment of focal seizure which in which the affected area is the hemisphere of the brain that is half part of the human brain the second use of phenytoin is as class 1 b lt and read make agent so this drug is also find its utility in treatment of some

Other quick conditions including tachycardia now let’s look at the iupac name of this compound here we find that here is the presence of a 5 mm but hit cyclic ring so though it is a two cycle our numbering will be start with this nitrogen so it is number 1 this is 2 3 4 and this will be number 5 so normal teacher can be given in two ways if we consider this whole

Nucleus so this whole nucleus is given the name hi den time so on hydrant i’m at push number five there is presence of two phenyl rings c6h5 is nothing but finn i’m so the iub same name of this compound can be written as five comma five die fina ill hydrant wine the second way of the nomenclature is to use the heterocyclic ring system over here so the head to

Cycle present here is in me does so lead in drink it is a saturated drink so the name given to this ring system is amida’s holy dean in emit a solid agree there is presence of three substituents one at pusher number two one at form of four and two substituents are present at which number five so on five we have presence of two phenyl rings so we will call it five

Gram of five die phenyl the basic nucleus is emit a solid in this double bond o is considered as on katan so emit a solid is now suffixed with on so this two aqsa groups are presented push number two and at position number four so emitters only deal is now suffix do eight to come a food dye on so this name will be phi phi – i’ll emitters only deal to four die on so

Both the names can be the iupac names for phenytoin next we move on to the mechanism of action of this compound which is very important one in view of the examination the mechanism of action of this compound include inhibition of voltage dependent sodium channels in case of epilepsy there is excessive firing of the neurons due to excess you entry of the sodium

Ions so to put the treatment of epilepsy it is general approach to innervate the sodium channels so that the excessive firing of the neurons can be stopped on so the fennekin is found to in a big the voltage dependent sodium channel and this inhibition leads to inhibition of firing of neurons so when the excessive firing of neuron is inhibited the epilepsy may

Get treated so that is a very simpler mechanism of action of this compound next we move on to the synthesis of this compound for synthesis our starting material is benzene here instead of c6h5 i wrote here it’s symbol ph ph simply stands for fin island that is nothing but c6h5 group so the starting material is benzene the benzene is treated with 30 percent naoh

Instances of ethanol ethanol can be written as etoh where et stands for a tile group so it tile with oh it is ethanol the reaction takes place with 30 percent any weight and it in all the second part which is included in the reaction is urea so the reaction between been jill and urea in presence of 30 percent naoh and ethanol so every look at the role of naoh it

Simply liberate the hydroxide ions which abstract these protons from the urea urea is a very weak nucleophile so for its better reaction with the carbonyl groups on the benzene sorry benzene it is needed that the hydroxy group must abstract the proton so that the negative charge will be developed over the nitrogen’s and both the nitrogen’s that can be the hair can

Be held as a strong nucleophile so ultimately the reaction between dental and urea leads to formation of intermediate which has this structure this compound is called as four five die hydroxy four five die failed not ill amida zoli dean two on if we look at this product we can find that simply the nitrogen’s of the urea get added on to the carbonyl carbon of the

Benzene so this reaction is nucleophilic addition reaction which gives formation of this intermediate species which will play a very important role in formation of phenytoin so this derivative then treated with concentrated hydrochloric acid which gives the h+ ions from here now this h+ ions will move on to one of the hydroxy group so there is reaction between

H plus and this oh h ion so there is a mole of a water molecule by this interaction so when hydroxy group react with this proton it takes to take this electron pair of this bond with itself into the water molecule so ultimately this bond then will be broken down and there is release of this water molecule like this carbon then acquire a positive charge so it will

Become a carbo cation to fulfill the requirement of electrons of this carbon this phenyl group will migrate over this carbon so when this migration takes place when of this bond will get broken down so when this bond is broken down the carbon tends to make a double bond with this oxygen so for making the bond between the carbon this oxygen lose this proton from

Here so there is removal of a proton so removal of proton and migration of a mile over to this carbon will lead to give us the compound which has this structure so this compound is called as phenytoin filadyne can be used as such for the treatment into its oral doses form but when there is need of its injectable form the phenytoin is gates converted into its salt

Which is called as phenytoin sodium so for conversion of phenytoin to its salt form the phenytoin is treated with sodium ethoxide if we look at the structure of phenytoin we find that this nh is present between two strong electron withdrawing carbonyl groups so this hydrogen may migrate over the oxygen of this carbonyl group to give us a total medical structure so

Here we have a tautomeric form like this now this automatic form consists of this hydroxyl group which is obtained by migration of the proton from this nitrogen to this oxygen so being alcoholic in nature this is quite acidic so this will liberate the proton from here to this ethoxy group and there is release of c2h5oh that is ethanol molecules release out vile

This sodium ion then will migrate over to the oxygen to give us the corresponding sodium salt of phenytoin which is called as phenytoin sodium so dear friends that is all about the preparation of phenytoin and its conversion to phenytoin sodium thanks for watching the video please like it share it and please don’t forget to subscribe thank you

Transcribed from video
Phenytoin synthesis By Josh_Tutorials