Barbital


Barbital
Barbital
Systematic (IUPAC) name
5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione
Clinical data
MedlinePlus a682221
Pregnancy cat.  ?
Legal status  ?
Routes Oral
Pharmacokinetic data
Half-life 30.3 (± 3.2) hours
Identifiers
CAS number 57-44-3 YesY
ATC code N05CA04
PubChem CID 2294
DrugBank DB01483
ChemSpider 2206 YesY
UNII 5WZ53ENE2P YesY
KEGG D01740 YesY
ChEBI CHEBI:31252 YesY
ChEMBL CHEMBL444 YesY
Chemical data
Formula C8H12N2O3 
Mol. mass 184.193 g/mol
SMILES eMolecules & PubChem
 YesY(what is this?)  (verify)

Barbital (marketed under the brand name Veronal), also called barbitone, was the first commercially marketed barbiturate. It was used as a sleeping aid (hypnotic) from 1903 until the mid-1950s. The chemical names for barbital are diethylmalonyl urea or diethylbarbituric acid. Veronal was prepared by condensing diethylmalonic ester with urea in the presence of sodium ethoxide, and then by adding at least two molar equivalents of ethyl iodide to the silver salt of malonylurea or possibly to a basic solution of the acid. The result was an odorless, slightly bitter, white crystalline powder.

Contents

Synthesis

Barbital was first synthesized in 1902 by German chemists Emil Fischer and Joseph von Mering. They published their discovery in 1903 and it was marketed in 1904 by the Bayer company as “Veronal”. A soluble salt of barbital was marketed by the Schering company as “Medinal.” It was dispensed for “insomnia induced by nervous excitability”.[1][unreliable source?] It was provided in either capsules or cachets. The therapeutic dose was ten to fifteen grains (0.65-0.97 grams). 3.5 to 4.4 grams is the deadly dose but sleep has also been prolonged up to ten days with recovery.

Barbital can be synthesized in a condensation reaction from urea and a diethyl malonate derivative:

Barbital Synthese.svg

Pharmacology

Veronal was considered to be a great improvement over the existing hypnotics. Its taste was slightly bitter, but an improvement over the strong, unpleasant taste of the commonly used bromides. It had few side effects. Its therapeutic dose was far below the toxic dose. However, prolonged usage resulted in tolerance to the drug, requiring higher doses to reach the desired effect. Fatal overdoses of this slow acting hypnotic were not uncommon.

Notes

  1. ^ [1]

 This article incorporates text from a publication now in the public domainChisholm, Hugh, ed (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. 

References

  • Fischer, Emil and Joseph von Mering, “Ueber eine neue Klasse von Schlafmitteln”, Therap Gegenw 44:97-101, 1903.
  • "Veronal", in Finley, Ellingwood, M.D. The American Materia Medica, Therapeutics and Pharmacognosy", 1919. [2], accessed 07 Nov 2005.

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Look at other dictionaries:

  • barbital — [ barbital ] n. m. • 1959; de barbit(urique) et suff. al ♦ Pharmacol. Barbiturique hypnotique et sédatif à action lente. ⇒ véronal, et aussi phénobarbital. Des barbitals. ● barbital nom masculin Barbiturique hypnotique à longue durée d action. (C …   Encyclopédie Universelle

  • barbital — barbitál s. n. Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  BARBITÁL s.n. (med.) Hipnotic barbituric cu acţiune de lungă durată. [< fr. barbital]. Trimis de LauraGellner, 13.09.2007. Sursa: DN  BARBITÁL s. n. hipnotic… …   Dicționar Român

  • barbital — ☆ barbital [bär′bi tôl΄, bär′bital΄ ] n. [ BARBIT(URIC ACID) + AL] diethylbarbituric acid, C8H12N2O3, a drug in the form of a white powder, used as a hypnotic and sedative: it is habit forming and toxic …   English World dictionary

  • Barbital — Strukturformel Allgemeines Freiname Barbital Andere Namen …   Deutsch Wikipedia

  • Barbital — estructura química del Barbital. Veronal (o Medinal, barbital, barbitone, barbiturato dietílico, dietilmalonilurea) es el nombre comercial del primer sedativo y somnífero del grupo de los barbitúricos. Fue introducido en el mercado a principios… …   Wikipedia Español

  • Barbital — Bar|bi|tal [Kurzw. aus ↑ Barbitursäure u. ↑ al (2)], das; s, e; Syn.: 5,5 Diethylbarbitursäure, Veronal®: farblose, bitter schmeckende Kristalle, Smp. 188–192 °C, Verwendung als Puffersubstanz (früher auch als Schlafmittel). Die Endung barbital… …   Universal-Lexikon

  • barbital — noun Etymology: barbituric + al (as in Veronal, trademark for barbital) Date: 1919 a crystalline barbiturate C8H12N2O3 used as a sedative and hypnotic often in the form of its soluble sodium salt …   New Collegiate Dictionary

  • barbital — /bahr bi tawl , tal /, n. Pharm. a barbiturate compound, C7O3N2H12, formerly used as a hypnotic. [1915 20; BARBIT(URIC ACID) + (VERON)AL] * * * …   Universalium

  • barbital — noun The first commercially marketed barbiturate, used as a hypnotic drug until the mid 1950s. Syn: barbitone, diethylbarbituric acid, diethylmalonyl urea …   Wiktionary

  • barbital — An obsolescent hypnotic and sedative; available as b. sodium (soluble b.), with the same uses; often used as a buffer. SYN: 5,5 diethylbarbituric acid, Veronal. * * * bar·bi·tal bär bə .tȯl, .tal n a crystalline barbiturate C8H12N2O3 formerly… …   Medical dictionary


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