Chloral_hydrate

Chloral hydrate
IUPAC name	2,2,2-trichloroethane-1,1-diol
Other names	trichloroacetaldehyde monohydrate Tradenames: Aquachloral, Novo-Chlorhydrate, Somnos, Noctec, Somnote
Identifiers
CAS number	[302-17-0]
PubChem	2707
SMILES	ClC(Cl)(Cl)C(O)O
InChI	1/C2H3Cl3O2/c3-2(4,5)1(6)7/h1,6-7H
Properties
Molecular formula	C2H3Cl3O2
Molar mass	165.403 g/mol
Appearance	Colorless solid
Density	1.91 g/cm3
Melting point	57 °C, 330 K, 135 °F
Boiling point	98 °C, 371 K, 208 °F
Pharmacology
Bioavailability	well absorbed
Routes of administration	Oral capsule/syrup, rectal suppository
Metabolism	converted to trichloroethanol, hepatic and renal
Elimination half-life	8–10 hours in plasma
Excretion	bile, feces, urine (various metabolites not unchanged)
Legal status	Schedule IV(US)
Pregnancy category	C(US)
Hazards
MSDS	External MSDS
EU classification	Harmful (Xn)
R-phrases	R22 R36 R37 R38
Related compounds
Related compounds	Chloral, chlorobutanol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Chloral hydrate is a sedative and hypnotic drug as well as a chemical reagent and precursor. The name chloral hydrate indicates that it is formed from chloral (trichloroacetaldehyde) by the addition of one molecule of water. Its chemical formula is C₂H₃Cl₃O₂.

It was discovered through the chlorination of ethanol in 1832 by Justus von Liebig in Gießen.Justus Liebig (1832). "Ueber die Zersetzung des Alkohols durch Chlor". Annalen der Pharmacie 1 (1): 31-32. doi:10.1002/jlac.18320010109. Justus Liebig (1832). "Ueber die Verbindungen, welche durch die Einwirkung des Chlors auf Alkohol, Aether, ölbildendes Gas und Essiggeist entstehen". Annalen der Pharmacie 1 (2): 182-230. doi:10.1002/jlac.18320010203.  The sedative properties where first published in 1869 and subsequently because of its easy synthesis it had a wide spread use.Liebreich, Oskar (1869). Das Chloralhydrat : ein neues Hypnoticum und Anaestheticum und dessen Anwendung in der Medicin ; eine Arzneimittel-Untersuchung. Müller.  It was widely abused and misprescribed in the late 19th century. Chloral hydrate is soluble in both water and alcohol, readily forming concentrated solutions. A solution of chloral hydrate in alcohol called "knockout drops" was used to prepare a Mickey Finn.

It is, together with chloroform, a minor side-product of the chlorination of water, if organic resudues are present in the water, concentrations rarely exceeding 5 micrograms per litre (µg/l).

Production

Chloral hydrate is produced from chlorine and ethanol in acidic solution. In basic conditions the haloform reaction takes place and chloroform is produced.

4 Cl₂ + C₂H₅OH + H₂O → Cl₃CCH(OH)₂ + 5 HCl

Uses

Synthesis

Chloral hydrate is a cheaply available building block chemical. It is the starting material for the production of chloral, which is produced by the distillation of a mixture of chloral hydrate and sulfuric acid, which serves as the desiccant.

Notably, it is used to synthesize isatin. In this synthesis, chloral hydrate reacts with aniline and hydroxylamine to give a condensation product which cyclicizes in sulfuric acid to give the target compound:C. S. Marvel and G. S. Hiers (1941). "Isatin". Org. Synth.; Coll. Vol. 1: 327. 

Sedative

Chloral hydrate is used for the short-term treatment of insomnia and as a sedative before minor medical or dental treatment. It was largely displaced by the mid-20th century by barbituratesTariq, Syed H. and Shailaja Pulisetty; “Pharmacotherapy for Insomnia”, Clinics in Geriatric Medicine (24), 2008 p. 93-105 PMID: 18035234 and subsequently by benzodiazepines. It was also formerly used in veterinary medicine as a general anesthetic. Today, it is commonly used as an ingredient in the veterinary anesthetic Equithesin.

In therapeutic doses for insomnia chloral hydrate is effective within sixty minutes, it is metabolized within 4 minutes into trichloroethanol by erythrocytes and plasma esterases and many hours later into trichloroacetic acid. Higher doses can depress respiration and blood pressure. An overdose is marked by confusion, convulsions, nausea and vomiting, severe drowsiness, slow and irregular breathing, cardiac arrhythmia and weakness. It may also cause liver damage and is moderately addictive, as chronic use is known to cause dependency and withdrawal symptoms. The chemical can potentiate various anticoagulants and is weakly mutagenic in vitro and in vivo^{[citation needed]}.

Chloral hydrate is now illegal in the United States without a prescription. Chloral hydrate is a schedule IV controlled substance in the United States. Its properties have sometimes led to its use as a date rape drug.

See also

• Jennie Bosschieter (1882–1900) who was murdered in Paterson, New Jersey on October 19, 1900.
• John Tyndall (1820-1893) who died of an accidental overdose.
• Anna Nicole Smith (1967-2007) who died of an accidentalAnna Nicole Smith Autopsy Report. XI. Manner of death. A. The Exclusion of Homicide The Smoking Gun combination of chloral hydrate with three benzodiazepines, as announced by forensic pathologist Dr. Joshua Perper on 3/26/07. Chloral hydrate was the major factor, but none of these drugs would have been sufficient by itself to cause her death.Anna Nicole Smith Autopsy Released. Coroner: Ex-Playmate died from accidental sedative overdose The Smoking Gun
• Marilyn Monroe had chloral hydrate in her possession, and it has been speculated that it contributed to her death.Marily Monroe. Theories Crime Library
• Hank Williams came under the spell of a man calling himself "Doctor" Toby Marshall (actually a paroled forger), who often supplied him with prescriptions and injections of chloral hydrate, which Marshall claimed was a pain reliever.Hank Williams summary Book Rags
• William S. Burroughs was expelled from school for experimenting with chloral hydrate along with another pupil. The incident is detailed in the writer\'s foreword to Junkie.
• Mary Todd Lincoln was given chloral hydrate for sleep problems. See Mary Todd Lincoln by Jean Baker and Mary: Mrs. A. Lincoln, by Janis Cooke Newman.
• It was used in the murder-suicides of the People\'s Temple in Jonestown, Guyana.

Chloral in fiction and film

• Bram Stoker, "Dracula," 1897
• Edith Wharton, "The House of Mirth." New York, C. Schribner’s Sons, 1905.
• Evelyn Waugh, Vile Bodies. London, Chapman & Hall Ltd., 1930.
• Margery Allingham, "The Case of the Late Pig." Hodder & Stoughton, 1937.
• Agatha Christie, "And Then There Were None." Dodd, Mead and Company, 1940.
• Rex Stout, "The Final Deduction," Chapter 7. Viking Press, 1961.
• From Russia with Love, Movie, 1963.
• Jimmy Breslin, "The Gang That Couldn\'t Shoot Straight," 1969.
• The Living Daylights, Movie, 1987.
• Caleb Carr, "The Alienist." Random House, 1994.
• Sarah Waters, Affinity. London: Virago Press, 1999.

References

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