Title: Barbital
CAS Registry Number: 57-44-3
CAS Name: 5,5-Diethyl-2,4,6(1H,3H,5H)-pyrimidinetrione
Additional Names: 5,5-diethylbarbituric acid; barbitone; diethylmalonylurea
Trademarks: Veronal
Molecular Formula: C8H12N2O3
Molecular Weight: 184.19
Percent Composition: C 52.17%, H 6.57%, N 15.21%, O 26.06%
Literature References: Prototype of the barbiturate hypnotics. Prepn: M. Conrad, M. Guthzeit, Ber. 15, 2841 (1882); E. Fischer, A. Dilthey, Ann. 335, 334 (1904). Use as physiological buffer: L. Michaelis, J. Biol. Chem. 87, 33 (1930); in enzyme determn: J. Bergerman, Clin. Chem. 12, 797 (1966).
Properties: Faintly bitter needles (trigonal in the stable phase) from water, mp 188-192°. Can be sublimed in vacuo. pK (25°) 7.43. One gram dissolves in about 130 ml water, 13 ml boiling water, 14 ml alcohol, 75 ml chloroform, 35 ml ether. Sol in acetone, ethyl acetate, alkalies, petr ether, acetic acid, amyl alcohol, pyridine, aniline, nitrobenzene.
Melting point: mp 188-192°
pKa: pK (25°) 7.43
Derivative Type: Sodium salt
CAS Registry Number: 144-02-5
Additional Names: Barbital sodium; sodium 5,5-diethylbarbiturate; barbitone sodium; soluble barbital; sodium diethylmalonylurea
Trademarks: Veronal sodium; Medinal
Molecular Formula: C8H11N2NaO3
Molecular Weight: 206.17
Percent Composition: C 46.61%, H 5.38%, N 13.59%, Na 11.15%, O 23.28%
Properties: Bitter crystals or powder. One gram dissolves in 5 ml water, 2.5 ml boiling water, 400 ml alc. Aq soln is alkaline to litmus and phenolphthalein. pH of 0.1 molar aq soln, 9.4.
NOTE: This is a controlled substance (depressant): 21 CFR, 1308.14.
Use: Biological buffer.
Therap-Cat: Sedative, hypnotic.
Therap-Cat-Vet: Sedative, hypnotic.
Keywords: Sedative/Hypnotic; Barbituric Acid Derivatives.
Barbituric Acid Barium Acetate Barium Benzenesulfonate Barium Bromate Barium Bromide

Barbital ball-and-stick.png
Systematic (IUPAC) name
Clinical data
AHFS/ International Drug Names
MedlinePlus a682221
Legal status Schedule IV (US)
Routes Oral
Pharmacokinetic data
Half-life 30.3 (± 3.2) hours
CAS number 57-44-3 YesY
ATC code N05CA04
PubChem CID 2294
DrugBank DB01483
ChemSpider 2206 YesY
KEGG D01740 YesY
ChEBI CHEBI:31252 YesY
Chemical data
Formula C8H12N2O3 
Mol. mass 184.193 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.