Caffeine Chemical Formula
Caffeine is a purine alkaloid and a trimethyl xanthine that acts as a stimulant for the Central Nervous System (CNS). Its chemical formula is C8H10N4O2 and is also termed methyl theobromine, 1,3,7-Trimethylxanthine, 7-methyltheophylline, guaranine, or theine. It appears as an odorless white crystalline purine and has a bitter taste. It is a methylxanthine alkaloid that occurs naturally in the seeds, leaves, and fruit of several plants and trees native to Africa, East Asia, and South America. It can be synthesized by the reaction between dimethylurea and malonic acid. Caffeine is derived naturally from purine xanthine, which is present in more than sixty plants, including coffee, tea, and cocoa. It is the most often-used psychoactive substance worldwide. Upon consumption, caffeine enters the body and binds to adenosine receptors in the central nervous system (CNS), preventing adenosine from binding. There are both positive and negative health impacts of caffeine. After repeated daily use, caffeine can cause a moderate form of drug dependence. So, when an individual stops using it after repeated use, it results in symptoms like sleepiness, headaches, and irritability.
Structure of Caffeine
The chemical formula of caffeine is C8H10N4O2, i.e., it is composed of eight carbon atoms, ten hydrogen atoms, four nitrogen atoms, and two oxygen atoms. The structure of caffeine is similar to that of the purine ring. Caffeine is a trimethylxanthine that is composed of two fused pyrimidinedione and imidazole rings and has three methyl groups located at positions 1, 3, and 7. Pyrimidinedione rings and imidazole rings are heterocyclic rings, where a pyrimidinedione ring is a 6-member ring with two nitrogen atoms, and an imidazole ring is a 5-member ring with two nitrogen atoms.

Preparation of Caffeine
- Caffeine is a methylxanthine alkaloid that occurs naturally in the seeds, leaves, and fruit of several plants and trees native to Africa, East Asia, and South America.
- It can be synthesized by the reaction between dimethylurea and malonic acid.
- It can also be produced when theobromine is treated with methyl iodide and sodium methoxide.
- When uric acid is treated with methyl iodide in an alkaline solution, it produces 1,3,7-trimethyluric acid. On heating this further with phosphoryl chloride (POCl3), it produces chlorocaffeine, which forms caffeine on further reduction with hydrogen iodide.

- Caffeine is produced as a by-product in the manufacture of decaffeinated coffee by decaffeination. In the process of decaffeination, caffeine and decaffeinated coffee are produced by extracting caffeine from its natural sources, like coffee.
Properties of Caffeine
Chemical Formula | C8H10N4O2 |
---|---|
IUPAC Name | 1,3,7-trimethylpurine-2,6-dione |
SMILES | CN1C=NC2=C1C(=O)N(C(=O)N2C)C |
Molar mass | 194.194 g/mol |
Appearance | White crystals |
Odor | Odorless |
Taste | Bitter |
Density | 1.23 g/cm3 |
Melting point | 235 to 238 °C (anhydrous) |
Boiling Point | 178 °C |
Solubility | Slightly soluble in water and organic solvent, and moderately soluble in ether |
Uses of Caffeine
- Caffeine is a stimulant for the central nervous and respiratory systems. It can be used to treat and prevent premature infant breathing disorders. It enhances athletic performance in both aerobic and anaerobic situations. It is considered a morning fuel and can delay or stop sleep and enhance task performance during sleep deprivation. It is used in energy drinks, soft drinks, and other beverages.
Side Effects of Caffeine
- Overdosage of caffeine may result in caffeine intoxication, which is a state of overstimulation of the central nervous system. It is a clinically significant, temporary condition that develops during or shortly after consuming caffeine.
- A high intake of caffeine in energy drinks was associated with short-term cardiovascular adverse effects.
- Ingestion of more than 400mg of caffeine per day may lead to sleeplessness, anxiety, restlessness, stomach discomfort, nausea, an elevated pulse, respiratory symptoms, headaches, stress, agitation, hyperventilation, hallucinations, diuresis, and bleeding disorders.
FAQs on Caffeine
Question 1: How is caffeine prepared from uric acid?
Answer:
When uric acid is treated with methyl iodide in an alkaline solution, it produces 1,3,7-trimethyluric acid. On heating this further with phosphoryl chloride (POCl3), it produces chlorocaffeine, which forms caffeine on further reduction with hydrogen iodide.
Question 2: What is the structure of caffeine?
Answer:
The chemical formula of caffeine is C8H10N4O2, i.e., it is composed of eight carbon atoms, ten hydrogen atoms, four nitrogen atoms, and two oxygen atoms. The structure of caffeine is similar to that of the purine ring.
Question 3: What is meant by caffeine?
Answer:
Caffeine is a purine alkaloid and a trimethyl xanthine that acts as a stimulant for the Central Nervous System (CNS). Its chemical formula is C8H10N4O2.
Question 4: What are the uses of caffeine?
Answer:
Caffeine is a stimulant for the central nervous and respiratory systems. It enhances athletic performance in both aerobic and anaerobic situations. It is considered a morning fuel and can delay or stop sleep and enhance task performance during sleep deprivation. It is used in energy drinks, soft drinks, and other beverages.
Question 5: What are the properties of caffeine?
Answer:
Caffeine is a purine alkaloid whose chemical formula is C8H10N4O2. It appears as an odorless, white crystalline purine and has a bitter taste. Its melting point is 235-238 °C and its boiling point is 178 °C. Its molecular weight and density are 194.194 g/mol and 1.23 g/cm3, respectively. It is moderately soluble in water at room temperature but is freely soluble in boiling water.
Question 6: What are the side effects of caffeine?
Answer:
Overdosage of caffeine may result in caffeine intoxication, which is a state of overstimulation of the central nervous system.
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