Chloral hydrate

Chloral hydrate

Names
Preferred 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 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:28142 Y
ChEMBL	ChEMBL455917 Y
ChemSpider	2606 Y
DrugBank	DB01563 Y
ECHA InfoCard	100.005.562
EC Number	206-117-5
KEGG	D00265 Y
PubChem	2707
RTECS number	FM875000
UNII	418M5916WG Y
InChI InChI=1S/C2H3Cl3O2/c3-2(4,5)1(6)7/h1,6-7H Y Key: RNFNDJAIBTYOQL-UHFFFAOYSA-N Y InChI=1/C2H3Cl3O2/c3-2(4,5)1(6)7/h1,6-7H Key: RNFNDJAIBTYOQL-UHFFFAOYAY
SMILES ClC(Cl)(Cl)C(O)O
Properties
Chemical formula	C2H3Cl3O2
Molar mass	165.39 g·mol−1
Appearance	Colorless solid
Odor	Aromatic, slightly acrid
Density	1.9081 g/cm3
Melting point	57 °C (135 °F; 330 K)
Boiling point	98 °C (208 °F; 371 K)
Solubility in water	very soluble
Solubility	very soluble in benzene, ethyl ether, ethanol
log P	0.99
Acidity (pKa)	9.66, 11.0
Structure
Crystal structure	monoclinic
Pharmacology
ATC code	N05CC01 (WHO)
Pregnancy category	US: C (Risk not ruled out)
Routes of administration	Oral syrup, rectal suppository
Pharmacokinetics:
Bioavailability	Well absorbed
Metabolism	Hepatic and renal (Converted to trichloroethanol)
Biological half-life	8–10 hours
Excretion	Bile, feces, urine (various metabolites not unchanged)
Legal status	CA: Uncontrolled US: Schedule IV
Hazards
Safety data sheet	External MSDS
EU classification (DSD)	Harmful (Xn)
R-phrases	R22 R36 R37 R38
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1100 mg/kg (mouse, oral)
Related compounds
Related compounds	Chloral, chlorobutanol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Chloral hydrate is an organic compound with the formula C₂H₃Cl₃O₂. It is a colorless solid. It has limited use as a sedative and hypnotic pharmaceutical drug. It is also a useful laboratory chemical reagent and precursor. It is derived from chloral (trichloroacetaldehyde) by the addition of one equivalent of water.

It was discovered through the chlorination (halogenation) of ethanol in 1832 by Justus von Liebig in Gießen. Its sedative properties were first published in 1869 and subsequently, because of its easy synthesis, its use was widespread. It was widely used recreationally and misprescribed in the late 19th century. Chloral hydrate is soluble in both water and ethanol, readily forming concentrated solutions. A solution of chloral hydrate in ethanol called "knockout drops" was used to prepare a Mickey Finn. More reputable uses of chloral hydrate include its use as a clearing agent for chitin and fibers and as a key ingredient in Hoyer's mounting medium, which is used to prepare permanent or semi-permanent microscope slides of small organisms, histological sections, and chromosome squashes. Because of its status as a regulated substance, chloral hydrate can be difficult to obtain. This has led to chloral hydrate being replaced by alternative reagents in microscopy procedures.

It is, together with chloroform, a minor side-product of the chlorination of water when organic residues such as humic acids are present. It has been detected in drinking water at concentrations of up to 100 micrograms per litre (µg/L) but concentrations are normally found to be below 10 µg/L. Levels are generally found to be higher in surface water than in ground water.