Dichloroacetic acid

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Structural formula
Structure of dichloroacetic acid
General
Surname Dichloroacetic acid
other names
  • Dichloroethanoic acid
  • DCA
Molecular formula C 2 H 2 Cl 2 O 2
Brief description

colorless liquid with a pungent odor

External identifiers / databases
CAS number 79-43-6
EC number 201-207-0
ECHA InfoCard 100.001.098
PubChem 6597
ChemSpider 10771217
DrugBank DB08809
Wikidata Q412845
properties
Molar mass 128.94 g mol −1
Physical state

liquid

density

1.57 g cm −3 (20 ° C)

Melting point

9-13 ° C

boiling point

194 ° C

Vapor pressure

0.19 h Pa (20 ° C)

pK s value

1.29

solubility
  • miscible with water
  • very soluble in DMSO, ethanol and acetone
Refractive index

1.466

safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
05 - Corrosive 09 - Dangerous for the environment

danger

H and P phrases H: 314-400
P: 273-280-301 + 330 + 331-305 + 351 + 338-308 + 310
Toxicological data
Thermodynamic properties
ΔH f 0

−496.3 kJ / mol

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Dichloroacetic acid ( DCA for short , from English dichloroacetic acid ) is a chlorinated carboxylic acid in which two hydrogen atoms of the methyl group are substituted by two chlorine atoms . The salts are called dichloroacetates.

Occurrence

Dichloroacetic acid can arise in chlorinated drinking water when it comes into contact with organic matter.

Extraction and presentation

Dichloroacetic acid can be obtained from trichloroacetic acid or from the reaction of acetic acid with chlorine, although a mixture of mono-, di- and trichloroacetic acid is formed that is difficult to separate. Direct access is obtained by converting chloral hydrate and potassium cyanide or potassium hexacyanidoferrate (II) in aqueous solution by refluxing.

use

Dichloroacetic acid is used as a solvent and as a starting material for the synthesis of other chemicals (such as sulfonamides ).

Drug

The use of dichloroacetate as a medicinal substance is being tested in several diseases in clinical studies . In lactic acidosis , it inhibits the enzyme's own kinase of the enzyme complex pyruvate dehydrogenase . In Crohn's disease , it has been shown to be beneficial in mice by stimulating intestinal regeneration and increasing mitochondrial function.

Since a scientific publication in January 2007, its use as a drug against specific forms of cancer has also been the subject of studies. To date, there is insufficient evidence of clinical efficacy and safety for commercial marketing. A study had to be stopped in 2006 because of nerve damage. Due to the lack of patentability, the financing of clinical studies is very difficult, as there is no financial incentive for pharmaceutical companies.

safety instructions

The IARC classified dichloroacetic acid as possibly carcinogenic in 2014.

See also

Individual evidence

  1. ↑ Entry on dichloroacetic acid. In: Römpp Online . Georg Thieme Verlag, accessed on October 12, 2014.
  2. ↑ a b c d e f g Entry on dichloroacetic acid in the GESTIS substance database of the IFA , accessed on February 22, 2017(JavaScript required) .
  3. ↑ a b Lawrence H. Keith, Douglas B. Walters; The National Toxicology Program's Chemical Data Compendium; ISBN 978-0-87371-716-8
  4. ↑ Data sheet dichloroacetic acid from Sigma-Aldrich , accessed on February 21, 2013 ( PDF ).
  5. ↑ Entry on dichloroacetic acid in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
  6. ↑ a b AMA Archives of Industrial Hygiene and Occupational Medicine. Vol. 4, Pg. 119, 1951 .
  7. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-21.
  8. ↑ Greenfacts: Dichloroacetic acid .
  9. ↑ WHO: Dichloroacetic Acid in Drinking-water (PDF file; 183 kB).
  10. ↑ Ernst Albert Schmidt: Detailed textbook of pharmaceutical chemistry. F. Vieweg and Son, 1901, p. 408 ( limited preview in Google book search).
  11. ↑ International Agency for Research on Cancer : Dichloroacetic acid .
  12. ↑ Sevana Khaloian, Eva Rath, Dirk Haller et al: Mitochondrial impairment drives intestinal stem cell transition into dysfunctional Paneth cells predicting Crohn's disease recurrence. Gut 2020; 0: 1–13, February 28, 2020, accessed April 15, 2020 (English).
  13. ↑ Small molecule offers big hope against cancer ( Memento February 27, 2007 in the Internet Archive ), University of Alberta Express News, January 16, 2007
  14. ↑ NZZ online: Cancer cells under forced ventilation . April 4, 2007.
  15. ↑ Rosemary Cashman: Dichloroacetic Acid (DCA) for brain tumors. (PDF; 1.6 MB) BC Cancer Agency, accessed on February 1, 2012 (English).
  16. ↑ N. Zhang, AF Palmer: Development of a dichloroacetic acid-hemoglobin conjugate as a potential targeted anti-cancer therapeutic. In: Biotechnology and bioengineering. Volume 108, Number 6, June 2011, pp. 1413-1420, doi: 10.1002 / bit.23071 . PMID 21328317 .
  17. ↑ Franziska Badenschier : Experts warn against supposed miracle cure. spiegel.de, March 30, 2007, accessed February 1, 2012 .
  18. ↑ FAZ Community Blogs: Old molecule as a cancer drug? .
  19. ↑ IARC Monograph 106 - Dichloroacetic Acid, 2014