Title: Amobarbital
CAS Registry Number: 57-43-2
CAS Name: 5-Ethyl-5-(3-methylbutyl)-2,4,6-(1H,3H,5H)-pyrimidinetrione
Additional Names: 5-ethyl-5-isopentylbarbituric acid; 5-ethyl-5-isoamylbarbituric acid; barbamil; amylobarbitone; 5-isoamyl-5-ethylbarbituric acid; pentymal
Trademarks: Amal (Knoll); Amasust (Knoll); Amytal (Flynn); Eunoctal (Houd?; Isomytal (Nippon Shinyaku); Mylodorm (G.P.); Sednotic (Dista); Stadadorm (Stada)
Molecular Formula: C11H18N2O3
Molecular Weight: 226.27
Percent Composition: C 58.39%, H 8.02%, N 12.38%, O 21.21%
Literature References: Prepn: US 1514573 (1924). Metabolism: Frey, Magnussen, Arzneim.-Forsch. 16, 612 (1966). Toxicity data: K. Irrgang, ibid. 15, 688 (1965). Comprehensive description: N. A. A. Mian et al., Anal. Profiles Drug Subs. 19, 27-58 (1990).
Properties: Slightly bitter crystals, mp 156-158°. One gram dissolves in 1300 ml water, in 5 ml alc, in 17 ml chloroform, in 6 ml ether. Freely sol in benzene; sol in alkaline solns. Insol in petr ether, aliphatic hydrocarbons. A satd aq soln is acid to litmus paper. Dissolves in aq solns of alkali hydroxides and carbonates. pH of a saturated soln in water about 5.6. pKa (25°C) 8.0. LD50 in mice (mg/kg): 212 s.c. (Irrgang).
Melting point: mp 156-158°
pKa: pKa (25°C) 8.0
Toxicity data: LD50 in mice (mg/kg): 212 s.c. (Irrgang)
Derivative Type: Sodium salt
CAS Registry Number: 64-43-7
Trademarks: Sodium Amytal (Flynn)
Molecular Formula: C11H17N2NaO3
Molecular Weight: 248.25
Percent Composition: C 53.22%, H 6.90%, N 11.28%, Na 9.26%, O 19.33%
Properties: Hygroscopic, friable granules of powder. Slightly bitter taste. Very soluble in water; sol in alcohol (1:1). Practically insol in ether.
NOTE: This is a controlled substance (depressant): 21 CFR, 1308.12 and 1308.13.
Therap-Cat: Sedative, hypnotic.
Therap-Cat-Vet: Sedative, hypnotic.
Keywords: Sedative/Hypnotic; Barbituric Acid Derivatives.
Amocarzine Amodiaquin Amolanone Amoproxan Amorolfine

Amobarbital ball-and-stick.png
Systematic (IUPAC) name
Clinical data
AHFS/ Micromedex Detailed Consumer Information
Pregnancy cat.  ?
Legal status Schedule IV (CA) Schedule II/Schedule III (US)
Routes Oral, IM, IV, Rectal
Pharmacokinetic data
Bioavailability  ?
Metabolism Hepatic
Half-life 8–42 hours
Excretion Renal
CAS number 57-43-2 YesY 64-43-7 (sodium salt)
ATC code N05CA02
PubChem CID 2164
DrugBank DB01351
ChemSpider 2079 YesY
KEGG D00555 YesY
Chemical data
Formula C11H18N2O3 
Mol. mass 226.272
 YesY (what is this?)  (verify)

Amobarbital (formerly known as amylobarbitone or sodium amytal) is a drug that is a barbiturate derivative. It has sedative-hypnotic properties. It is a white crystalline powder with no odor and a slightly bitter taste. It was first synthesized in Germany in 1923. If amobarbital is taken for extended periods of time, physical and psychological dependence can develop. Amobarbital dependence mimics delirium tremens and may be life threatening.