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paraldehyde
Sign in to saveAlso known as Paral, paracetaldehyde, acetaldehyde trimer, paraacetaldehyde, 2,4,6-trimethyl-s-trioxane, 1,3,5-trimethyl-2,4,6-trioxane, 2,4,6-trimethyl-1,3,5-trioxane
Paraldehyde is the cyclic trimer of acetaldehyde molecules. Formally, it is a derivative of 1,3,5-trioxane, with a methyl group substituted for a hydrogen atom at each carbon. The corresponding tetramer is metaldehyde. A colourless liquid, it is sparingly soluble in water and highly soluble in ethanol. Paraldehyde slowly oxidizes in air, turning brown and producing an odour of acetic acid. It attacks most plastics and rubbers and should be kept in glass bottles.
Chemical data
- Formula
- C6H12O3
- Molecular weight
- 132.16 g/mol
- IUPAC name
- 2,4,6-trimethyl-1,3,5-trioxane
- SMILES
- CC1OC(OC(O1)C)C
- InChIKey
- SQYNKIJPMDEDEG-UHFFFAOYSA-N
- XLogP
- 0.7
- Polar surface area
- 27.7 Ų
- H-bond donors
- 0
- H-bond acceptors
- 3
- Formal charge
- 0
via PubChem
Research
577 papers- Paraldehyde.Journal of applied toxicology : JAT · 1991
- Paraldehyde acidosis.The American journal of medicine · 1967
- Paraldehyde.The Hospital · 1893
- [Paraldehyde].The Canadian nurse · 1948
- Eclampsia.Clinics in obstetrics and gynaecology · 1982
via PubMed
~6 min read
Encyclopedic overview
10 sectionsContents
- Preparation
- Stereochemistry
- Reactions
- Medical applications
- As a hypnotic/sedative
- As anti-seizure drug
- Administration
- Industrial applications
- References
- External links
Paraldehyde is the cyclic trimer of acetaldehyde molecules. Formally, it is a derivative of 1,3,5-trioxane, with a methyl group substituted for a hydrogen atom at each carbon. The corresponding tetramer is metaldehyde. A colourless liquid, it is sparingly soluble in water and highly soluble in ethanol. Paraldehyde slowly oxidizes in air, turning brown and producing an odour of acetic acid. It attacks most plastics and rubbers and should be kept in glass bottles.
Paraldehyde was first observed in 1835 by the German chemist Justus Liebig; its empirical formula was determined in 1838 by Liebig's student Hermann Fehling. The German chemist Valentin Hermann Weidenbusch (1821–1893), another of Liebig's students, synthesized paraldehyde in 1848 by treating acetaldehyde with acid (either sulfuric or nitric acid) and cooling to 0°C. He found it quite remarkable that when paraldehyde was heated with a trace of the same acid, the reaction went the other way, recreating acetaldehyde.
Excerpted from Wikipedia’s “paraldehyde” article, available under the CC BY-SA 4.0 licence.