Paraldehyde

Paraldehyde
Names
	IUPAC name 2,4,6-Trimethyl-1,3,5-trioxane
	Systematic IUPAC name 2,4,6-Trimethyl-1,3,5-trioxane
Identifiers
CAS Number	123-63-7 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:27909 ;
ChEMBL	ChEMBL1410743 ;
ChemSpider	21106173 ;
ECHA InfoCard	100.004.219
EC Number	204-639-8;
KEGG	D00705 ;
MeSH	Paraldehyde
PubChem CID	31264;
UNII	S6M3YBG8QA ;
CompTox Dashboard (EPA)	DTXSID9023419 ;
	InChI InChI=1S/C6H12O3/c1-4-7-5(2)9-6(3)8-4/h4-6H,1-3H3 Key: SQYNKIJPMDEDEG-UHFFFAOYSA-N ; InChI=1/C6H12O3/c1-4-7-5(2)9-6(3)8-4/h4-6H,1-3H3 Key: SQYNKIJPMDEDEG-UHFFFAOYAO;
	SMILES CC1OC(C)OC(C)O1;
Properties
Chemical formula	C6H12O3
Molar mass	132.159 g·mol−1
Appearance	Colourless liquid
Odor	Sweet
Density	0.996 g/cm3
Melting point	12 °C (54 °F; 285 K)
Boiling point	124 °C (255 °F; 397 K)
Solubility in water	soluble 10% vv at 25 Deg.
Vapor pressure	13 hPa at 20 °C
Magnetic susceptibility (χ)	−86.2·10−6 cm3/mol
Pharmacology
ATC code	N05CC05 (WHO)
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Flammable
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H226
Precautionary statements	P210, P233, P303+P361+P353, P370+P378, P403+P235, P501
Flash point	24°C - closed cup
Explosive limits	Upper limit: 17 %(V); Lower limit: 1.3 %(V)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	Oral - Rat - 1,530 mg/kg; Dermal - Rabbit - 14,015 mg/kg
Safety data sheet (SDS)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Paraldehyde is the cyclic trimer of acetaldehyde molecules.^[2] 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.^[3]^[4] 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.^[5]^[6]

Paraldehyde has uses in industry and medicine.

^ ^a ^b ^c Sigma-Aldrich Co., Paraldehyde.
^ Wankhede, N N; Wankhede, D S; Lande, M K; Arbad, B R (March 2006). "Densities and ultrasonic velocities of binary mixtures of 2,4,6-trimethyl-1,3,5-trioxane + n-alcohols at 298.15, 303.15 and 308.15 K" (PDF). Indian Journal of Chemical Technology. 13 (2): 149–155.
^ Liebig, Justus (1835) "Ueber die Producte der Oxydation des Alkohols" (On the products of the oxidation of ethanol), Annalen der Chemie, 14 : 133–167; see especially p. 141.
^ Fehling, H. (1838) "Ueber zwei dem Aldehyd isomere Verbindungen" (On two compounds that are isomeric to acetaldehyde), Annalen der Chemie, 27 : 319–322; see pp. 321–322.
^ Weidenbusch, H. (1848) "Ueber einige Producte der Einwirkung von Alkalien und Säuren auf den Aldehyd" (On some products of the reaction of alkalies and acids with acetaldehyde), Annalen der Chemie, 66 : 152-165; see pp. 155–158.
^
Paraldehyde was first synthesized by Weidenbusch in 1848:
- (Editorial staff) (April 15, 1885) "The action of paraldehyde," The Therapeutic Gazette, 9 : 247-250; see p. 247.
- See also: Henry Watts, Matthew Moncrieff Pattison Muir, and Henry Forster Morley, Watts' Dictionary of Chemistry, rev'd, vol. 1 (London, England: Longmans, Green, and Co., 1905), p. 106.
For biographical information about Valentin Hermann Weidenbusch, see:
- Neill Busse, Der Meister und seine Schüler: Das Netzwerk Justus Liebigs und seiner Studenten [The Master and His Disciples: The network of Justus Liebig and his students] (Hildesheim, Germany: Georg Olms Verlag, 2015); for Weidenbusch's dates, see p. 274.
- See also: Joseph S. Fruton (March 1988) "The Liebig research group: A reappraisal," Proceedings of the American Philosophical Society, 132 (1) : 1–66; see p. 59.
- See also: Deutsche Biographische Enzyklopädie Archived 2014-08-11 at the Wayback Machine (German Biographical Encyclopedia), p. 1154.

[Sigma-1] Sigma-Aldrich Co., Paraldehyde.

[2] Wankhede, N N; Wankhede, D S; Lande, M K; Arbad, B R (March 2006). "Densities and ultrasonic velocities of binary mixtures of 2,4,6-trimethyl-1,3,5-trioxane + n-alcohols at 298.15, 303.15 and 308.15 K" (PDF). Indian Journal of Chemical Technology. 13 (2): 149–155.

[3] Liebig, Justus (1835) "Ueber die Producte der Oxydation des Alkohols" (On the products of the oxidation of ethanol), Annalen der Chemie, 14 : 133–167; see especially p. 141.

[4] Fehling, H. (1838) "Ueber zwei dem Aldehyd isomere Verbindungen" (On two compounds that are isomeric to acetaldehyde), Annalen der Chemie, 27 : 319–322; see pp. 321–322.

[5] Weidenbusch, H. (1848) "Ueber einige Producte der Einwirkung von Alkalien und Säuren auf den Aldehyd" (On some products of the reaction of alkalies and acids with acetaldehyde), Annalen der Chemie, 66 : 152-165; see pp. 155–158.

[6] Paraldehyde was first synthesized by Weidenbusch in 1848:
(Editorial staff) (April 15, 1885) "The action of paraldehyde," The Therapeutic Gazette, 9 : 247-250; see p. 247.

See also: Henry Watts, Matthew Moncrieff Pattison Muir, and Henry Forster Morley, Watts' Dictionary of Chemistry, rev'd, vol. 1 (London, England: Longmans, Green, and Co., 1905), p. 106.
For biographical information about Valentin Hermann Weidenbusch, see:
Neill Busse, Der Meister und seine Schüler: Das Netzwerk Justus Liebigs und seiner Studenten [The Master and His Disciples: The network of Justus Liebig and his students] (Hildesheim, Germany: Georg Olms Verlag, 2015); for Weidenbusch's dates, see p. 274.

See also: Joseph S. Fruton (March 1988) "The Liebig research group: A reappraisal," Proceedings of the American Philosophical Society, 132 (1) : 1–66; see p. 59.

See also: Deutsche Biographische Enzyklopädie Archived 2014-08-11 at the Wayback Machine (German Biographical Encyclopedia), p. 1154.

[7] (Editorial staff) (April 15, 1885) "The action of paraldehyde," The Therapeutic Gazette, 9 : 247-250; see p. 247.

[8] See also: Henry Watts, Matthew Moncrieff Pattison Muir, and Henry Forster Morley, Watts' Dictionary of Chemistry, rev'd, vol. 1 (London, England: Longmans, Green, and Co., 1905), p. 106.

[9] Neill Busse, Der Meister und seine Schüler: Das Netzwerk Justus Liebigs und seiner Studenten [The Master and His Disciples: The network of Justus Liebig and his students] (Hildesheim, Germany: Georg Olms Verlag, 2015); for Weidenbusch's dates, see p. 274.

[10] See also: Joseph S. Fruton (March 1988) "The Liebig research group: A reappraisal," Proceedings of the American Philosophical Society, 132 (1) : 1–66; see p. 59.

[11] See also: Deutsche Biographische Enzyklopädie Archived 2014-08-11 at the Wayback Machine (German Biographical Encyclopedia), p. 1154.

[1]

[2]

[3]

[4]

[5]

[6]