Aspirin, Chlorobutol, Salicyclic Acid, Saccharin, Ethyl Benzoate etc.

1. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 1
CHAPTER 16
STUDY OF FOLLOWING OFFICIAL
COMPOUNDS
CHLOROBUTOL
H3C CH3
OHCl3C
Chlorobutol
FORMULA: C4H7OCl3
IUPAC NAME: 1,1,1- Trichloro-2-methyl-2-propanol.
OTHER NAME: Chloretone, Chlorobutanol
PREPARATION:
It is prepared by direct combination of acetone with chloroform in presence of
solid KOH.
H3C CH3
O
CHCl3
Acetone
Chloroform
KOH
H3C CH3
OHCl3C
Chlorobutol
ASSAY:
A weighed quantity of substance is dissolved in alcohol and hydrolysed by being
boiled under reflex with Aq.NaOH. The chlorides ions are determined by
Volhard’s method with N/10 AgNO3 an N/10 NH4SCN. Before the thiocynate
titration the mixture is shaken in presence of small quantity of nitro benzene in
order to coagulate the AgCl precipitate. The result is expressed in terms of the

2. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 2
hemi hydrate, so that 1000 ml of N/10 AgNO3 are equivalent to 1/30 of C4
H7Cl3O. 1/2 H2O
USES:
 Chlorobutanol has antibacterial and fungicidal effects
 It is used at a concentration of 0.5% as a preservative in injections, eye drops
and mouth washs, salves, creams and ointments as well as cosmetics.
DIMERCAPROL
STRUCTURE:
SHHO
SH
FORMULA: C3H8OS2
IUPAC Name: 2,3-dimercaptopropan-1-ol
OTHER NAME: 2,3 dimercapto‐1‐propanol
ASSAY: Dissolve about 0.12 gm, accurately weighed in 20 ml of HCl (0.1 mol/lt)
Vs and titrate rapily with ioine Vs using starch is an indicator. Report the
experiment test without the test liquid being examined, and make any necessary
corrections. Each 1ml of iodine Vs is equivalent to 6.211mg of C3H8OS2
USES:
 Dimercaprol is a chelating agent that is used to remove a heavy metal (such
as As, Hg, Au, Bi, Ni and Sb) from the blood.
 Dimercaprol is used to treat arsenic, gold, or mercury poisoning.
 It is also used together with another medicine called edetate disodium
(EDTA) to treat lead poisoning.
 Used to treat Wilson’s disease (Wilson's disease or hepatolenticular
degeneration is an autosomal recessive genetic disorder in which copper
accumulates in tissues; this manifests as neurological or psychiatric
symptoms and liver disease.)

3. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 3
GLYCERYL TRINITRATE (GTN)
STRUCTURE:
CH2ONO2
O2NOHC
CH2ONO2
Glycerol Trinitrate
FORMULA: C3H5N3O9
OTHER NAME: Nitroglycerine
PREPARATION: It is prepared by slowly adding glycerol to an ice cooled
mixture of conc.H2SO4 and conc.HNO3. The solution is cautiously run into ice
cold water; the nitroglycerine then separates as heavy oil which is purified by
repeated washing with cold water.
CH2OH
HOHC
CH2OH
3HNO3
CH2ONO2
O2NOHC
CH2ONO2
Glycerol Glycerol Trinitrate
Conc. H2SO4
ASSAY:
Nitrate is determined calorimetrically in a weighed quantity of the powdered
tablets by interaction with phenol‐2,4‐disulphonic acid and subsequent
classification with ammonia. The yellow color is matched against that of solution
containing known quantities of potassium nitrate which have been treated
similarly. The assay depends on the formation of colored nitro compounds by the
interaction of the glycerol trinitrate with the phenol‐2,4‐ disulphonic acid, and the
sub sequent conversion of these into intensely ammonium salts. The method
suffers from certain disadvantages, the most important of which is the difficulty of
correctly matching the yellow color.
USES:
 It is used to manufacture of dynamite and blasting gelatin which are
comparatively safe explosives.

4. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 4
 In tablets it is given in certain diseases of heart
 Glyceryl trinitrate is used to treat angina (sudden pains in the chest), heart
failure and in heart surgery.
 It is also used as a rectal ointment to relieve the pain from anal fissures,
which are tears in the lining of your anal passage.
 It is a nitrate, sometimes known as a nitrate vasodilator.
UREA
STRUCTURE:
C
O
H2N NH2
Urea
FORMULA: CO(NH2)2
PREPARATION:
A laboratory method is to evaporate solution of ammonium cynate to dryness
(wohler) about 95% NH4CN becomes converted into urea by reversible isomeric
change.
2NH3 CO2 C
O
H2N ONH4
C
O
H2N NH2
Ammonium Carbomate Urea
It is also synthesized by interaction of ammonia with carbonyl chloride.
ASSAY:
The official process is based on the method of Richmond and hill. This hydrolysis
the saccharin to the sodium salt of o‐sulphonyl benzoic acid, without loss of
ammonia
USES:
 Urea is widely used in fertilizers as a source of nitrogen and is an important
raw material for the chemical industry.

5. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 5
 Urea is the world's most commonly used nitrogen fertilizer and indeed
more urea is manufactured by mass than any other organic chemical.
Containing 46% N, it is the most concentrated nitrogen fertilizer, and is
readily available as free-flowing prills (granules).
ETHYLENE DIAMINE DIHYDRATE
STRUCTURE:
H2N
NH2
Ethylene diamine
FORMULA: C2H4(NH2)2.2H2O
PREPARATION:
From 1,2‐ dichloroethane and ammonia at maintaining the temperature of 180 ºC.
H2N
NH2
Ethylene diamine
Cl
Cl
1,2-dichloroethane
2NH3
ASSAY:
By titration with N/1 HCl to the bromophenol blue indicator, this indicates the
formation of the dihydrochloric acid.
Uses:
 Ethylene diamine is used in large quantities for production of many
industrial chemicals.
 Ethylene diamine is the chelating agent EDTA, Salts of ethylene bisdithio
carbamate are commercially significant fungicide

6. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 6
VANILLIN
STRUCTURE:
OCH3
OH
Vanillin
CHO
FORMULA: C8H8O3
IUPAC: 3-hydroxy-4-methoxybenzaldehyde
PREPARATION:
It is the flavouring agent of the vanilla pods can be made synthetically from
guaicol by Remier–Tiemann reaction.
OCH3
OH
Guaiacol
KOH/CHCl3
OCH3
OH
Vanillin
CHO
ASSAY:
Weigh accurately about 0.12gm dissolve 20ml of ethanol add 60ml of CO2 free
H2O and titrate with 0.1m NaOH determining the end point, potentiometrically
each 1ml of 0.1m NaOH is equivalent to 0.01521g of C8H8O3
USES:
 As a flavouring agent particularly in chocolate ice cream and confectionary
(The largest use of vanillin is as a flavoring, usually in sweet foods. The ice

7. PHARMAWISDOM Pharm.D
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cream and chocolate industries together comprise 75% of the market for
vanillin as a flavoring)
 Vanillin is also used in the fragrance industry, in perfumes, and to mask
unpleasant odors or tastes in medicines, livestock fodder, and cleaning
products.
 Vanillin has been used as a chemical intermediate in the production
of pharmaceuticals and other fine chemicals.
PARALDEHYDE
STRUCTURE:
O O
O CH3H3C
CH3
Paraldehyde
FORMULA: C6H12O3
IUPAC: 2,4,6-trimethyl-1,3,5-trioxane
PREPARATION: It is prepared by treatment of acetaldehyde with an acid
catalyst.
H3C CH
O
Acetaldehyde
3
O O
O CH3H3C
CH3
Paraldehyde
H+
Catalyst
USES:
1. Paraldehyde is used to treat certain convulsive disorders (Anti conversant).

8. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 8
2. It also has been used in the treatment of alcoholism and in the treatment of
nervous and mental conditions to calm or relax patients who are nervous or
tense and to produce sleep.
3. Sedative and hypnotic
4. Obstetric analgesic
ETHYLENE CHLORIDE
STRUCTURE:
H2C CH2
Cl Cl
Ethylene Chloride
FORMULA: C2H4Cl2
OTHER NAME: 1,2-dichloroethane
PREAPARATION: Ethylene chloride is produced by the reaction of ethylene and
chlorine.
H2C CH2 H2C CH2
Cl Cl
Ethylene Chloride
Ethene
Cl2
FeCl3
ASSAY:
Stock, standard gas was created by static dilution form 100% analyte, mixed
volumetrically with input of O2, sample is verified by chromatography.
USES:
 Used as degreasen and paint remover.
 Controlling pain associated with injections, minor surgical procedures, and
certain other procedures.
 It is also used to temporarily relieve minor sports injuries.
 Ethylene chloride spray is a skin refrigerant.

9. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 9
LACTIC ACID
FORMULA: C3H6O3
STRUCTURE:
H3C
O
OH
OH
Lactic Acid
PREAPARATION: Lactic acid has been prepared by brominating propionic acid
and hydrolysing the resultant 2‐bromopropionic acid to sodium lactate by heating
with dil.alkali.
H3C
O
OH
propionic acid
H3C
O
OH
3-bromo propionic acid
Br
H3C
O
OH
OH
Lactic Acid
Br2 Alk. NaOH
ASSAY:
A weighted quantity is diluted with H2O and boiled with N/1 sodium hydroxide
and excess of alkali is then determined by titration with N/1 HCl by using
phenolphthalein as indicator. The boiling alkali hydrolyses the condensation
products.
USES:
 Used in dairy products
 For determining of tides
 Ethyl and butyl lactates are used as plasticers.
 Lactic acid is used as a food preservative, curing agent, and flavoring
agent. It is an ingredient in processed foods and is used as a decontaminant
during meat processing.

10. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 10
TARTARIC ACID
FORMULA: C4H6O6
STRUCTURE:
H
C
C
H
COOH
COOH
HO
HO
Tartaric Acid
PREPARATION:
From Maleic Acid: Maleic acid produced industrially by oxidation of cyclohexone
is treated with alkaline KMNO4 to get m‐tartaric acid.
HC
HC
COOH
COOH
H
C
C
H
COOH
COOH
H2O [OH]
KMnO4 HO
HO
Tartaric Acid
Maleic Acid
ASSAY:
Titration with N/1 NaOH using phenolphthalein as indicator
1,000ml of N/1 alkali are equivalent to ½ C4H6O6
USES:
 Used in carbonated beverages and effervescent tablets
 In baking powder
 In silvering of mixtures
 In medical analysis,
 Tartaric acid is used to make solutions for the determination of glucose.

11. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 11
CITRIC ACID
FORMULA: C6H8O7
STRUCTURE:
CH2COOH
C COOHHO
CH2COOH
Citric Acid
PREPARATION: From molasses‐ it containing sucrose is diluted to water and
subjected to fermenting with a micro organism Aspergillus niger.
C12H22O11 H2O
Air
A.Niger
CH2COOH
C COOHHO
CH2COOH
Citric Acid
Sucrose
ASSAY:
The fermentation process is carried out for 7‐10 days at 26‐28ºC.The resulting
solution of citric acid is neutralized with Ca(OH)2 to form insoluble calcium
citrate. This is washed with H2O and decomposed with dilute H2SO4.The calcium
sulphate is filtered of and the solution concentration under vaccum to get crystals
of citric acid.
USES:
 Used as a mordant
 Used as esters that is good plasticizers for lacquers and vanishers.
 Citric Acid is a naturally occurring preservative used in many applications
including canning, flavoring, cleaning, and even photography development.

12. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 12
SALICYLIC ACID
STRUCTURE:
OH
COOH
Salicyclic Acid
FORMULA: C7H6O3
IUPAC: 2-hydroxybenzoic acid
PREPARATION: This involves the treatment of sodium phenoxide with CO2 at
1250C under 6atm of pressure followed by acid hydrolyses therefore acid is
formed (Kolbe’s Reaction).
O-
Na+
OH
COONa
OH
COOH
Salicyclic AcidSod. salicylateSod. phenoxide
CO2
125o
C
6 atm H+
/H2O
ASSAY:
Titration with N/2 NaOH in alcoholic solution using phenol as red indicator. The
end point marks the completion of sodium salt. The presence of hydroxyl group
makes the acid stronger than benzoic. The constant is 1×10‐3 and the pH of sodium
salicylate is therefore close to 7.
1,000ml of N/2 alkali are equivalent to ½ C6H4(OH)CO2H
USES:
 Used as antiseptic and disinfectant.
 Salicylic acid is a keratolytic (peeling agent).
 Salicylic acid causes shedding of the outer layer of skin.
 Salicylic acid topical (for the skin) is used in the treatment of acne, dandruff,
seborrhea, or psoriasis, and to remove corns, calluses, and warts.

13. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 13
ASPIRIN
COOH
OCOCH3
Aspirin
FORMULA: C9H8O4
OTHER NAMES: Acetyl salicylic acid, 2-acetoxybenzoic acid
PREPARATION:
To prepare aspirin, salicylic acid is reacted with an excess of acetic anhydride. A
small amount of a strong acid is used as a catalyst which speeds up the reaction.
COOH
OH
Salicyclic Acid
COOH
OCOCH3
(CH3CO)2O
CH3COOH
Acetic anhydride
Aspirin
H3PO4
ASSAY:
Dissolve 1.5 gm in 15 ml of ethanol add 5l of 0.5 M NaOH , boil gently for 10
minutes , cool & titrate the excess of alkali with 0.5 M HCl cool using phenol red
solution as indicator .
USES:
1. Aspirin is used to reduce fever and relieve mild to moderate pain from
conditions such as muscle aches, toothaches, common cold, and headaches.
2. It may also be used to reduce pain and swelling in conditions such as
arthritis.
3. Aspirin is known as a salicylate and a non-steroidal anti-inflammatory drug
(NSAID).

14. PHARMAWISDOM Pharm.D
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METHYL SALICYLATE
STRUCTURE:
OH
COOCH3
Methyl Salicyclate
FORMULA: C8H9O3
IUPAC: Methyl 2-hydroxybenzoate
PREPARATION:
It is prepared by esterfying salicylic acid with methanol in presence of H2SO4.
OH
COOH
Salicyclic Acid
CH3OH
H2SO4
OH
COOCH3
Methyl Salicyclate
H2O
ASSAY:
By a modification of the method for the determination of the esters. Instead of
being first neutralized to phenolphthalein, on alcoholic solution is saponified by
directly with alc.KOH. No correction is made for any free acid present, but
permiscible amount of this is controlled by the above mention test. To ensure
complete hydrolysis longer boiling is necessary than in the official process for the
determination of the esters.
USES:
 It is used in hair tonics and ointments for treating aches, sproins and bruises.
 Methyl salicylate cream is used for: Temporary relief of minor aches and
pains caused by arthritis, simple backache, strains, sprains, and bruises.
 It is a topical analgesic.

15. PHARMAWISDOM Pharm.D
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ETHYL BENZOATE
STRUCTURE:
C
O
OCH2CH3
Ethyl benzoate
FORMULA: C9H10O2
PREPARATION: Ethyl alcohol is treated with Benzoic Acid in the presence of
strong acid (H2SO4).
C
O
OH
Benzoic Acid
CH3CH2OH
ethanol
C
O
OCH2CH3
Ethyl benzoate
ASSAY:
Place about 0.08g accurately weighted in a round glass stopped flask, add 2.5ml of
NaOH and boil gently under reflex condenser for 3mins.
USES:
 Used as artificial fruit flavouring agent.
 It is used as an antifungal preservative

16. PHARMAWISDOM Pharm.D
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BENZYL BENZOATE
STRUCTURE:
O
O
Benzyl Benzoate
FORMULA: C14H12O2
PREPARATION: Prepared by Esterification of benzyl alcohol with benzoic acid
of catalyst.
H2
C OH
Benzyl chloride Benzoic Acid
HO
O
O
O
Na
Benzyl Benzoate
ASSAY:
Add about 2.0g accurately weighted 240ml of KOH/C2H5OH Vs and boil under
reflex for 1hr. Cool and titrate with HCl Vs using phenolphthalein or ethanol as
indicator. Repeat the operation without the test liquid being examined and make
any necessary correction.
Each 1ml of KOH/C2H5OH Vs equivalent to 106.1mg of C14H12O2
USES:
 Used as antiparasitic (scabicide‐topical use).
 It is used as an acaricide, scabicide, and pediculicide in veterinary hospitals.
 It is also a repellent for chiggers, ticks, and mosquitoes.
 It is an effective and inexpensive topical treatment for human scabies.

17. PHARMAWISDOM Pharm.D
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DIMETHYL PTHALATE
STRUCTURE:
O
O
Dimethyl Phthalate
OCH3
OCH3
FORMULA: C10H10O4
PREPARATION: It is prepared by oxidation of o‐xylene and subsequent,
Esterification with methyl alcohol.
CH3
CH3
o-xylene
O
O
O
phthalic anhydride
O
O
Dimethyl Phthalate
OCH3
OCH3
O2 CH3OH
H2SO4
ASSAY:
Weigh accurately about 2g of dimethyl phthalate into a 250ml flask attached to
reflex condenser and add 50cc of 0.5 NaOH and add 10cc of H2O and reflex for 1
hr. wash down the sides of the container and glass connection with about 2.5cc of
water, cool and add 0.2cc of thymol blue and titrate excess alkalie with 0.5N HCl
to the production of yellow colour performance.
USES:
 Used as Ectoparasiticide (These drugs are used to kill the parasites that live
on the body surface)
 Solid rocket propellants
 In preparation of plastic
 Insect repellant

18. PHARMAWISDOM Pharm.D
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SODIUM LAURYL SULPHATE
STRUCTURE:
Na+
SO O
O
O-
H3C
SODIUM LAURYL SULPHATE
FORMULA: Na.C12H25SO4
PREPARATION: It is prepared by sulphating long chain fatty alcohols and
neutralizing with alkali to form the sodium salts. The alcohols are prepared by
reduction of coconut oil by high pressure hydrogenation using the catalyst
copper‐chromium oxide.
Na+
SO O
O
O-
H3C
SODIUM LAURYL SULPHATE
OHH3C
LAURYL ALCOHOL
NaOHH2SO4
ASSAY:
Weigh accurately about 1.15g, dissolve in sufficient water to produce 1,000ml
warming if necessary to 20.01ml add 15ml of chloroform 10ml of dil.H2SO4 and
dimethyl oracet blue solution and titrate with 0.004M benzethonium chloride, until
the chloroform layer acquires a permanent clear green colour. Each 1ml of 0.004M
benzethonium chloride is equivalent to 0.00115g of sodium alkali sulphates,
calculated as C12H25NaO4S.
USES:

19. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 19
 Pharmaceutical aid
 It Acts as surfactant
 Used as an emulsifier
SACCHARIN SODIUM
STRUCTURE:
O
N Na
S
O
O
Sodium Saccharin
H2O
FORMULA: C7H4NNaO3S
PREPARATION: When saccharin is treated with aqueous NaOH to form
saccharin sodium.
O
NH
S
O
O
saccharin
O
N Na
S
O
O
Sodium Saccharin
H2O
NaOH
ASSAY:
Weigh accurately about 0.15g, dissolve in 50ml of anhydrous glacial acetic acid.
With slight heating if necessary and carry out method A for non aqueous titration,
determining the end potentiometrically perform a blank determination and make
any necessary correction.
Each ml of 0.1M perchloric acid is equivalent to 0.02052g of C7H4NNaO3S.
USES:
 Pharmaceutical aid, preparation of toothpaste.

20. PHARMAWISDOM Pharm.D
S . S E E T A R A M S W A M Y , A s s t . P r o f e s s o r , C B C P Page 20
 Sodium saccharin is the solid form of the artificial sweetener saccharin.
 Saccharin is non-nutritive and is used to add sweetness to beverages and
foods without the calories or detrimental effects of consuming sugar.
 Using artificial sweeteners can help you reduce your consumption of sugar.
MEPHENSIN
STRUCTURE: 3-(o-tolyloxy)propane-1,2-diol
CH3
O OH
OH
Mephenesin
FORMULA: (C11H17N)2.H2SO4
PREPARATION:
It is synthesized from o‐cresol. It is treated with aq.NaOH to convert sodium salt
which undergoes nucleophillic substitute with 3‐chloro‐1,2 propanediol to give
mephensin.
CH3
OH
Cl OH
OH
3-chloropropane-1,2-diol
o-cresol
CH3
O OH
OH
Mephenesin
ASSAY:
Test for mephensin, injection equivalent is measured accurately 1g of mephensin
in position
USES:
 Used as analgesic, axiolytic, and anti‐fungal sometimes
 Muscular relaxant
 Mephenesin is a centrally acting muscle relaxant. It can be used as an
antidote for strychnine.