Phenytoin(dilantin) is an anti-convulsant drug or anti-epileptic drug. It can be prepared from benzil, an organic compound formed by the oxidation of benzoin.

1. Guided By: Submitted By:
Ms. Aswathy Shaji (Guest Lecturer) Ansa Mathew
Department of Chemistry B.Sc. Chemistry
Mar Thoma College for Women Mar Thoma College for Women
Perumbavoor Perumbavoor

2. CONTENTS
OBJECTIVE
INTRODUCTION
PHENYTOIN
MATERIALS AND
METHODS
PREPARATIONS
RESULT AND
DISCUSSION CONCLUSION

3. OBJECTIVE
To 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.

4. 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.

5.  EXAMPLES OF AEDs
 Bromide- first anticonvulsant drug
 Phenobarbital
 Carbamazepine
 Phenytoin
 Valproic acid

6. PHENYTOIN
AED
Uses
 Prevention of tonic- clonic seizures.
 Acute treatment of generalized status epilepticus
Mode of administration
 Intravenously
 By mouth
Mode 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.

7. 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.

8. 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

9. MATERIALS AND METHODS
MATERIALS
1. Benzoin
2. Conc.HNO3
3. Urea
4. Ethanol
5. Dil.HCl
6. Sodium Hydroxide

10. 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.

11. 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

12. 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

13. RESULT AND DISCUSSION
IR ANALYSIS
IR Spectrum of Benzil

14. 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.

15. Structure Of Benzil

16. IR Spectrum Of Phenytoin

17. 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.

18. Structure Of Phenytoin

19. 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.

20. 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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