Dichloroacetic acid is an organochlorine compound whose chemical formula is CHCl2COOH. This is also termed dichloroethanoic acid, bichloroacetic acid, DCA, BCA, dichloracetic acid, or bichloracetic acid. This is often abbreviated as DCA and is an analog of acetic acid. It is derived from acetic acid where two of the three hydrogen atoms of the methyl group are replaced by chlorine atoms. It is made up of acetic acid carrying two chloro substituents at the 2-position. The conjugate base of dichloroacetic acid is dichloroacetate. DCA occurs in nature in Asparagopsis taxiformis, which is a seaweed. It is a highly corrosive liquid that is corrosive to metals and tissues and gives off acidic vapours. It emits toxic fumes of chlorides when heated to decomposition. It is used as a fungicide, as an astringent, and as a chemical intermediary in the production of organic compounds.
Structure of Dichloroacetic Acid
Dichloroacetic acid is an organochlorine compound whose chemical formula is CHCl2COOH. It is made up of acetic acid carrying two chloro substituents at the 2-position.
| Molecular formula | C2H2Cl2O2 |
|---|---|
| Linear formula | CHCl2COOH |
|
Canonical SMILES of Dichloroacetic Acid (SMILES: Simplified molecular-input line-entry system) |
C(C(=O)O)(Cl)Cl |
Dichloroacetic acid structure
Occurrence and Preparation of Dichloroacetic acid
DCA occurs in nature in Asparagopsis taxiformis, which is a seaweed. It is a byproduct of the chlorination of drinking water and is formed by the metabolism of several drugs or chemicals that contain chlorine.
The usual method for preparing DCA is the reduction of trichloroacetic acid (TCA). Hydrolysis of the methyl ester, which is readily available from the esterification of crude dichloroacetic acid, can yield an extremely pure dichloroacetic acid. DCA is also manufactured by the chlorination of acetic and chloroacetic acids.
DCA can also be synthesized from chloral hydrate by reacting calcium carbonate with chloral hydrate [CCl3CH(OH)2] in the presence of a small amount of sodium cyanide (NaCN), followed by acidification with concentrated hydrochloric acid.
2CCl3CH(OH)2 + 2CaCO3
(CHCl2COO)2Ca + CaCl2 + 2CO2 + 2H2O (CHCl2COO)2Ca + 2HCl → 2CHCl2COOH + CaCl2
The hydrolysis of dichloroacetyl chloride is the most cost-effective production method of dichloroacetic acid.
CHCl2COCl + H2O → CHCl2COOH + HCl
Properties of Dichloroacetic Acid
| Molecular formula | CHCl2COOH (or) C2H2Cl2O2 |
|---|---|
| IUPAC Name | 2,2-dichloroacetic acid |
| Molar Mass | 128.94 g/mol |
| Density | 1.563 g/cm3 |
| Appearance | Colourless liquid |
| Odour | Pungent odour |
| Melting point | 9 to 11 °C |
| Boiling point | 194 °C |
| Flash point | 113 °C – closed cup |
| Solubility | Miscible in water, ethanol, and diethyl ether |
| Hydrogen bond Donor count | 1 |
| Hydrogen bond Acceptor count | 2 |
| Rotatable Bond Count | 1 |
Uses of Dichloroacetic Acid
- DCA is used as an intermediate in organic synthesis, as a test reagent for analytical measurements during fibre manufacture, and also as a medicinal disinfectant.
- In the agricultural sector, DCA and its esters are used in the production of iron chelates.
- It is used as a cauterizing agent in medical practice.
- Both DCA and TCA are used in cosmetic treatments like chemical peels and tattoo removal.
- DCA and its salts might be effective to treat the rare condition of lactic acidosis. However, in a randomized controlled trial in kids with congenital lactic acidosis, it was found that DCA was ineffective.
- In animal and in vitro studies, it is observed that there is a slow growth of certain tumours with the use of DCA.
- In humans, it is used as an agent in chemotherapy for skin cancer treatment.
Hazards
- Inhalation of DCA may cause wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest.
- Contact with its molten form may cause severe skin burns and eye damage.
- Ingestion of DCA is harmful as the corrosive chemicals will destroy the membranes of the mouth, throat, and oesophagus.
- Furthermore, it may also cause damage to the lungs, liver, pancreas, kidneys, and brain.
- It emits toxic fumes of chlorides when heated to decomposition. It is very toxic to aquatic life.
FAQs on Dichloroacetic Acid Formula
Question 1: What is dichloroacetic acid?
Answer:
Dichloroacetic acid is an organochlorine compound whose chemical formula is CHCl2COOH. This is also termed dichloroethanoic acid, bichloroacetic acid, DCA, BCA, dichloracetic acid, or bichloracetic acid. This is often abbreviated as DCA and is an analog of acetic acid. It is derived from acetic acid where two of the three hydrogen atoms of the methyl group are replaced by chlorine atoms.
Question 2: How is dichloroacetic acid prepared?
Answer:
The usual method for preparing DCA is the reduction of trichloroacetic acid (TCA). Hydrolysis of the methyl ester, which is readily available from the esterification of crude dichloroacetic acid, can yield an extremely pure dichloroacetic acid. DCA is also manufactured by the chlorination of acetic and chloroacetic acids.
The hydrolysis of dichloroacetyl chloride is the most cost-effective production method of dichloroacetic acid.
CHCl2COCl + H2O → CHCl2COOH + HCl
Question 3: Mention some properties of dichloroacetic acid.
Answer:
Dichloroacetic acid is an organochlorine compound whose chemical formula is CHCl2COOH. Its molar mass is 128.94 g/mol and its density is 1.563 g/cm3. It appears as a colorless, crystalline solid melting at 49°F and has a pungent odor. It is a highly corrosive liquid that is corrosive to metals and tissues and gives off acidic vapors. It emits toxic fumes of chlorides when heated to decomposition. The melting point of DCA is 9 to 11 °C and its boiling point is 194 °C.
Question 4: Write about the solubility of dichloroacetic acid.
Answer:
Its solubility is miscible in water, ethanol, and diethyl ether, while it is soluble in acetone and slightly soluble in carbon tetrachloride.
Question 5: What are the uses of dichloroacetic acid?
Answer:
DCA is used as an intermediate in organic synthesis, as a test reagent for analytical measurements during fiber manufacture, and also as a medicinal disinfectant. In the agricultural sector, DCA and its esters are used in the production of iron chelates. It is used as a cauterizing agent in medical practice.
Question 6: Mention some hazards of DCA.
Answer:
Inhalation of DCA may cause wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest. Contact with its molten form may cause severe skin burns and eye damage. Ingestion of DCA is harmful as the corrosive chemicals will destroy the membranes of the mouth, throat, and esophagus. Furthermore, it may also cause damage to the lungs, liver, pancreas, kidneys, and brain. It emits toxic fumes of chlorides when heated to decomposition. It is very toxic to aquatic life.