How to Synthesis of Asprine


Aspirin is the most widely used over-the-counter drug in the world. The average tablet contains about 325 milligrams of acetylsalicylic acid with an inert binding material such as starch. Aspirin is used to relieve pain, reduce inflammation, and lower fever. Aspirin originally was derived by boiling the bark of the white willow tree. Although the salicin in willow bark has analgesic properties, purified salicylic acid was bitter and irritating when taken orally.

ASPIRIN - ACETYLSALICYLIC ACID

Introduction =

Aspirin is the most widely used over-the-counter drug in the world. The average tablet contains about 325 milligrams of acetylsalicylic acid with an inert binding material such as starch. Aspirin is used to relieve pain, reduce inflammation, and lower fever. Aspirin originally was derived by boiling the bark of the white willow tree. Although the salicin in willow bark has analgesic properties, purified salicylic acid was bitter and irritating when taken orally. Salicylic acid was neutralized with sodium to produce sodium salicylate, which was better-tasting but still irritated the stomach. Salicylic acid could be modified to produce phenylsalicylate, which was better tasting and less irritating, but released the toxic substance phenol when metabolized. Felix Hoffman and Arthur Eichengrün first synthesized the active ingredient in aspirin, acetylsalicylic acid, in 1893.

Reaction=

(C7H6O3) + (C4H6O3) ----> (C9H8O4) + (C2H4O2)
Salicylic acid Acetic anhyhdride Acetylsalicylic acid Acetic acid


How to Make Aspirin - Acetylsalicylic Acid
Materials
• 3.0 g salicylic acid
• 6 mL acetic anhydride*
• 5-8 drops of 85% phosphoric acid or concentrated sulfuric acid*
• distilled water (about 50 mL)
• 10 mL ethanol
• 1% iron III chloride (optional, to test purity)
*Use extreme caution when handling these chemicals. Phosphoric or sulfuric acid and acetic anhydride can cause severe burns.
Equipment
• filter paper (12.5 cm)
• ring stand with funnel
• two 400 mL beakers
• 125 mL Erlenmeyer flask
• 50 mL buret or measuring pipet
• 10 mL and 50 mL graduated cylinder
• fume hood, hot plate, balance
• dropper
• stirring rod
• ice bath
• wash bottle


How to Make Aspirin - Acetylsalicylic Acid - Procedure


1. Accurately weigh 3.00 grams of salicylic acid and transfer to a dry Erlenmeyer flask. If you will be calculating actual and theoretical yield, be sure to record how much salicylic acid you actually measured.
2. Add 6 mL of acetic anhydride and 5-8 drops of 85% phosphoric acid to the flask.
3. Gently swirl the flask to mix the solution. Place the flask in a beaker of warm water for ~15 minutes.
4. Add 20 drops of cold water dropwise to the warm solution to destroy the excess acetic anhydride.
5. Add 20 mL of water to the flask. Set the flask in an ice bath to cool the mixture and speed crystallization.
6. When the crystallization process appears complete, pour the mixture through a Buckner funnel.
7. Apply suction filtration through the funnel and wash the crystals with a few milliliters of ice cold water. Be sure the water is near freezing to minimize loss of product.
8. Perform a recrystallization to purify the product. Transfer the crystals to a beaker. Add 10 mL of ethanol. Stir and warm the beaker to dissolve the crystals.
9. After the crystals have dissolved, add 25 mL of warm water to the alcohol solution. Cover the beaker. Crystals will reform as the solution cools. Once crystallization has started, set the beaker in an ice bath to complete the recrystallization.
10. Pour the contents of the beaker into a Buckner funnel and apply suction filtration.
11. Remove the crystals to dry paper to remove excess water.
12. Confirm you have acetylsalicylic acid by verifying a melting point of 135°C.

Ueses :
Current uses of aspirin include:

 Over-the-counter pain relief, especially for headaches

 Reduction of swelling and inflammation in arthritis and injuries

 Anti-coagulant given to sufferers of heart attack, mini-stroke and unstable angina

 Can reduce severity of heart attack if taken at first symptoms

 Recovery after cardiovascular surgery (eg bypass operation)

 Treatment of rheumatoid arthritis, osteoarthritis and other rheumatoid diseases

Possible benefits of aspirin are being researched in:

 Migraine treatment

 Improving circulation in the gums

 Fighting ovarian, breast and colon cancer

 Prevention of cataracts

 Controlling pre-eclampsia

 Improving brain function, especially memory

 Reducing colorectal cancer repeating

 Prevention of adult leukaemia

 Prevention of HIV replicating

 Reduce prostrate cancer risk

 Increasing success rates of IVF programs

Is it suitable for everyone to use?

 In short, no it isn't.

 Aspirin isn't advised for the following groups without medical advice:
 Children under 16

 Asthmatics
 Anyone under 20 with a fever

 People with bleeding disorders

 Anyone with an ulcer or persistent stomach problems

 Diabetics on medication

 Heavy alcohol drinkers

 Healthy people for more than ten days

 G6P deficiency diseases

 Reduced kidney function or liver disease

 People on low sodium diets (buffered aspirin tablets contain sodium)

Side Effects Of aspirin :

Like all drugs, there are some risks of side effects from aspirin. Many are uncommon enough to be considered an acceptable risk for most patients, but there are some significant risks attached. Healthy people using aspirin occasionally as directed are unlikely to develop serious side effects.

The use of aspirin in children and teenagers with a fever, especially after a viral infection, has been associated with the development of a potentially fatal condition called Reye Syndrome. For that reason, it is recommended to NEVER GIVE ASPIRIN TO ANYONE UNDER THE AGE OF 16 or to anyone under 20 who has a fever.

Overdoses with aspirin are quite common and it is essential to keep them out of reach of children.

Aspirin can irritate the stomach, leading to nausea and vomiting, so it is best taken with or just after food. Other problems may be ringing in the ears, excessive bleeding, heartburn, indigestion and allergic reactions.

Analgesics like aspirin are excreted via the kidneys, and thus have the power to damage the kidneys and long term, low dose usage reduces renal function. Certain medical conditions and heavy drinking increase the risk of kidney damage.



Note: NEVER take aspirin if it has a vinegary smell as this means it is "off".


Comments

Author: Santosh Davari14 Jul 2011 Member Level: Gold   Points : 1

Hi,
Mahesh,nice article. This gives details of the aspirin. Share the contents, with proper punctuation marks.

Punctuation and proper grammar will provide you the benefit of more points.

Sharing such information will help to understand about the facts of dosages and its side effects on the human body.


Best Regards,
Santosh Davari.



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