Aspirin is a generic medication used for pain, fever, inflammation, heart attacks, etc. It is commonly prescribed because of its properties such as anti-inflammatory, anti–coagulatory, fever-reducing, and pain-relieving. The major component of Aspirin is acetylsalicylic acid which gives it all these properties. This is the reason Aspirin is also known as acetylsalicylic acid. Its molecular formula is [C_{9}H_{8}O_{4}].
Aspirin is NSAID (Nonsteroidal anti-inflammatory drug) but it suppresses the normal functioning of platelets. It is not recommended during pregnancy and to children with infections. It has various side effects as well such as high dose may result in the ringing of ears, Reye syndrome, nausea, upset stomach, headache, etc.
Acetylsalicylic acid was first produced by Alsatian Chemist Charles Frederic Gerhardt in 1853 from sodium salicylate and acetyl chloride. Soon the drug became famous and Bayer (a drug and dye firm) started producing it on a large scale. Bayer named it Aspirin. It was Bayer’s brand name for the drug. Its popularity declined in 1962 after the synthesis of drugs like paracetamol and ibuprofen.
Formula of Acetylsalicylic Acid
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S. No. |
IUPAC Name & Formula of Acetylsalicylic Acid |
|
|
1. |
Empirical Formula |
[C_{9}H_{8}O_{4}] |
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2. |
Molecular Formula |
[CH_{3}COOC_{6}H_{4}COOH , or , C_{9}H_{8}O_{4}] |
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3. |
Skeletal formula |
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|
4. |
IUPAC name |
2-acetoxybenzoic acid |
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5. |
Other general names |
Acetylsalicylic acid, Aspirin, acetylsalicylate. |
Structure of Acetylsalicylic Acid
Properties of Aspirin
Physical Properties of Aspirin – It Shows Following Physical Properties
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Its molar mass is 180.16 g/mol.
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Its melting point is 136 ℃.
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Its boiling point is 140 ℃.
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It’s soluble in water. 3g of Aspirin can dissolve in 1 liter of water.
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It is a white crystalline solid at room temperature.
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It is weakly acidic in nature. At 25 ℃ temperature, its acid dissociation constant is 3.5.
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Its density is [1.40 g.cm^{-3}].
Chemical Properties of Aspirin – It Shows Following Chemical Properties
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It gets hydrolyzed on coming in contact with moist air. Although it is stable in dry air.
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It easily decomposes in the solution of ammonium acetate, carbonates, citrates, or alkali metal hydroxides.
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It can be explosive when mixed with air in its powdered form.
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It is anti-inflammatory, anti–coagulatory, and analgesic.
Synthesis of Acetylsalicylic Acid
Aspirin is synthesized by the action of salicylic acid on acetic anhydride. It is an esterification reaction. In this reaction, when salicylic acid reacts with acetic anhydride, the hydroxyl group of salicylic acid converts into an ester group. This results in Aspirin and acetic acid. Sulfuric acid or phosphoric acid acts as catalysts. The reaction is given below
Uses of Acetylsalicylic Acid/Aspirin
Acetylsalicylic acid is mainly used in the medical field. A few of its medical uses are listed below –
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It is an analgesic and is used to get relief from acute pain.
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It is highly effective against muscle pain, bloating, skin irritation, gastric distension.
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It is also used for the treatment of migraine.
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It is effective against cluster headaches.
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It is used in fever.
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It is anti-inflammatory so it is used to treat inflammation.
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It is useful in the treatment of those parts of the heart which had an attack.
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Aspirin is advised to take after surgeries like PCIs etc.
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It reduces the risk of getting cancer.
Side Effects of Aspirin
Although Aspirin is very useful against many diseases, it has various side effects as well. It must not be taken in very high amounts because in very high concentrations acetylsalicylic acid may cause hallucinations and even death.
It causes nausea, vomiting, bloating, muscle cramps, gastrointestinal irritation, gastritis, diarrhea, gastric ulcer, decrease in blood pressure, drowsiness, headache, heartburn, etc.
Aspirin: Summary in Tabular Form
|
Aspirin |
|
|
Chemical formula |
[CH_{3}COOC_{6}H_{4}COOH , or , C_{9}H_{8}O_{4}] |
|
IUPAC Name |
2-acetoxybenzoic acid |
|
Other names |
Acetylsalicylic acid, Aspirin, acetylsalicylate. |
|
Molar mass |
180.16 g/mol |
|
Melting point |
136 ℃ |
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Boiling point |
140 ℃ |
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Density |
[1.40 g.cm^{-3}] |
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Appearance |
White crystalline |
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Odor |
Like vinegar (at higher concentrations) |
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State at ST |
Solid |
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Solubility in water |
Soluble ([3g.L^{-1}]) |
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Preparation |
By the reaction of salicylic acid and acetic anhydride in the presence of sulfuric acid/ phosphoric acid as catalyst. [C_{6}H_{4}(OH)COOH + (CH_{3}CO)_{2}O rightarrow CH_{3}COOC_{6}H_{4}COOH + CH_{3}COOH] |
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Main properties |
Anti-inflammatory, Analgesic |
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Main use |
To get relief from pain, fever, headache, etc. |
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Disadvantage |
Causes side effects like nausea, muscle cramps, bloating. |
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