preparation of phenytoin from benzil
TRANSCRIPT
Guided By: Submitted By: Ms. Aswathy Shaji (Guest Lecturer) Ansa MathewDepartment of Chemistry B.Sc. ChemistryMar Thoma College for Women Mar Thoma College for WomenPerumbavoor Perumbavoor
PREPARATION OF PHENYTOIN FROM BENZIL
CONTENTSOBJECTI
VEINTRODUCTION
PHENYTOIN
MATERIALS AND
METHODS
PREPARATIONS
RESULT AND DISCUSSION
CONCLUSION
OBJECTIVETo prepare Benzil by the oxidation of Benzoin.To prepare the anti-convulsant drug
‘Phenytoin’ from Benzil.Characterization of Benzil and Phenytoin by
their IR spectra.
INTRODUCTION DRUG It is a chemical substance used to treat, cure, prevent, diagnose a disease
or promote well-being.
ANTICONVULSANTS OR ANTIEPILEPTIC DRUGS (AEDs) Drugs used in the treatment of convulsive disorders like epileptic seizures. Provide symptomatic treatment only.
MODE OF ACTION Depress the CNS Non-specific Centrally acting Block sodium or calcium channels and reduce the release of excitatory
glutamate at high frequencies.
EXAMPLES OF AEDs Bromide- first anticonvulsant drug Phenobarbital Carbamazepine Phenytoin Valproic acid
PHENYTOINAEDUses Prevention of tonic- clonic seizures. Acute treatment of generalized status epilepticusMode of administration Intravenously By mouthMode of action Primary site of action appears to be the motor cortex,
where the spreading of seizure activity is inhibited. Phenytoin binds preferentially to the inactive form of the sodium channel.
Dosage of phenytoin Depends on blood serum levels i.e., between
10µg/mL and 20µg/mL. After the initial dose has been prescribed,
plasma levels should be determined and the dosage adjusted if necessary to obtain a level in the therapeutic range.
Excretion Most of the drug is excreted in the bile as
inactive metabolites which are then reabsorbed from the intestinal tract and excreted through the urine.
Common side effects
Nausea Stomach pain and loss of appetite Poor co-ordination Increased hair growth Enlargement of the gums Sleepiness Liver problems Bone marrow suppression Low blood pressure Toxic epidermal necrolysis
MATERIALS AND METHODSMATERIALS
1. Benzoin2. Conc.HNO3
3. Urea4. Ethanol
5. Dil.HCl6. Sodium Hydroxide
Methods
Infrared Spectroscopy- Spectroscopy that deals with the infrared region of the electromagnetic spectrum.
The instrument used is called infrared spectrometer or spectrophotometer.
A basic IR spectrum is essentially a graph of infrared light absorbance on the vertical axis vs. frequency or wavelength on the horizontal axis.
PREPARATION OF BENZIL
3g of Benzoin and 5mL of
conc.HNO3 are heated on a
water bath with a water
condenser , the flask being
subjected to occasional shaking.
Nitrous fumes are evolved and
crystals of Benzoin are converted to
yellow oil which after 2 hours of heating is free
from unchanged
Benzoin
The contents of the flask are poured into
water and the yellow
crystalline deposit is
separated by filtration.
It is then washed with water and
recrystallised from alcohol.
PREPARATIONS
PREPARATION OF PHENYTOIN
In an RB flask, 1.5g of Benzil, 0.75g of
urea, 22mL of Ethanol and 4.5mL
of 30% aqueous Sodium
Hydroxide are mixed.
The mixture is then boiled
gently for 2 hours on a water bath
After 2 hours, the reaction
mixture is cooled and
40mL of water is
added and the solution is filtered to remove the sparingly
soluble side product
The filtrate is then
acidified with 10mL of dil. HCl .
The product formed is filtered,
washed with water and kept for drying
RESULT AND DISCUSSIONIR ANALYSIS
IR Spectrum of Benzil
IR Spectrum Analysis Of Benzil
Benzil is synthesized by the oxidation of Benzoin.
The stretching frequency of
the free carbonyl group in the Benzil is
around 1700cm-1 .
A sharp band is obtained at
1600cm-1 . This is the characteristic stretching band
of Carbon-Carbon double bond.
The band appeared at
~3000cm-1 can be conveniently assigned to the aromatic C-H
stretching.
Structure Of Benzil
IR Spectrum Of Phenytoin
On comparison of the spectrum of phenytoin with that of Benzil, it is found that there are a few
noticeable changes between the two spectrums.
A new band has been occurred in the region 3400-
3100cm-1 This band corresponds to N-H
stretching. The broad character of the band is due to
H-bonding.
The band appeared at ~3000cm -1
corresponds to aromatic C-H
stretching.
The C=O stretching
vibrations can be seen around
the region corresponding to ~1700cm-1 .
The band appeared in between the
region 1400cm-1. and 1600 cm-1 gives the C-C
stretching vibrations of
aromatic ring.
Structure Of Phenytoin
Due to the small changes that happened in the spectrum of phenytoin when compared with that of Benzil, we can say that the structural similarity between phenytoin and Benzil is not much.
In phenytoin, in addition to two Benzene ring, the formation of a five member ring containing two C=O and the two N-H groups occurs.
CONCLUSION
In this present work, we prepared Benzil by the oxidation of
benzoin.
From Benzil, a major
anticonvulsant or an antiepileptic
drug named Phenytoin was
also synthesized.
Both the Benzil and Phenytoin
were characterized
by their IR spectra.
The difference in the spectral data indicates the change in the structures
of the two compounds.
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