Barbital

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Barbital
Systematic (IUPAC) name
5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione
Clinical data
AHFS/Drugs.comInternational Drug Names
MedlinePlusa682221
Legal statusSchedule IV (US)
RoutesOral
Pharmacokinetic data
Half-life30.3 (± 3.2) hours
Identifiers
CAS number57-44-3 YesY
ATC codeN05CA04
PubChemCID 2294
DrugBankDB01483
ChemSpider2206 YesY
UNII5WZ53ENE2P YesY
KEGGD01740 YesY
ChEBICHEBI:31252 YesY
ChEMBLCHEMBL444 YesY
Chemical data
FormulaC8H12N2O3 
Mol. mass184.193 g/mol
 YesY (what is this?)  (verify)
 
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Barbital
Systematic (IUPAC) name
5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione
Clinical data
AHFS/Drugs.comInternational Drug Names
MedlinePlusa682221
Legal statusSchedule IV (US)
RoutesOral
Pharmacokinetic data
Half-life30.3 (± 3.2) hours
Identifiers
CAS number57-44-3 YesY
ATC codeN05CA04
PubChemCID 2294
DrugBankDB01483
ChemSpider2206 YesY
UNII5WZ53ENE2P YesY
KEGGD01740 YesY
ChEBICHEBI:31252 YesY
ChEMBLCHEMBL444 YesY
Chemical data
FormulaC8H12N2O3 
Mol. mass184.193 g/mol
 YesY (what is this?)  (verify)

Barbital (as known in the United States) or barbitone (as known elsewhere), marketed under the brand names Veronal for the pure acid and Medinal for the sodium salt, was the first commercially available barbiturate. It was used as a sleeping aid (hypnotic) from 1903 until the mid-1950s. The chemical names for barbitone are diethylmalonyl urea or diethylbarbituric acid; hence, the sodium salt (known as medinal, a genericised trademark in the United Kingdom), is known also as sodium diethylbarbiturate. Barbitone 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.

Synthesis[edit]

Barbitone 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 barbitone 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.

Barbitone can be synthesized in a condensation reaction from urea and diethyl-2,2-diethylmalonate, a diethyl malonate derivative:

Barbital Synthese.svg

Pharmacology[edit]

Barbitone 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.

References[edit]

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

Bibliography[edit]