BUTALBITAL Property

Melting point:

139-140 °C

Boiling point:

365.66°C (rough estimate)

Density 

1.1672 (rough estimate)

refractive index 

1.5000 (estimate)

Flash point:

11 °C

storage temp. 

2-8°C

solubility 

soluble in DMSO, Methanol

form 

Solid

pka

pKa 12.36±0.05(H2O t=38.0 I=0.1) (Uncertain)

color 

White

Water Solubility 

1.702g/L(25 ºC)

BRN 

202119

EPA Substance Registry System

2,4,6(1H,3H,5H)-Pyrimidinetrione, 5-(2-methylpropyl)-5-(2-propen-1-yl)- (77-26-9)

Safety

Hazard Codes 

Xn,T,F

Risk Statements 

22-43-39/23/24/25-23/24/25-11

Safety Statements 

36-45-36/37-16

RIDADR 

UN 1230 3/PG 2

WGK Germany 

3

RTECS 

CP8750000

HazardClass 

6.1(b)

PackingGroup 

III

HS Code 

2933530000

Hazardous Substances Data

77-26-9(Hazardous Substances Data)

Toxicity

LD50 oral in bird - wild: 75mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H317May cause an allergic skin reaction

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

BUTALBITAL Chemical Properties,Usage,Production

Chemical Properties

White, crystalline powder; odorless; slightly bitter taste. Soluble in alcohol, ether, and chloroform; almost insoluble in water.

Originator

Axocet,Savage Labs

Uses

Controlled substance (depressant). Sedative, hypnotic.

Definition

ChEBI: A member of the class of barbiturates that is barbituric acid in which the hydrogens at position 5 are substituted by an allyl group and an isobutyl group. Frequently combined with other medicines, such as aspirin, paracetamol and codeine, it is used for reatment of pain and headache.

Manufacturing Process

1 mole of sodium is dissolved in 10 to 12 times its weight of absolute alcohol under a reflux condenser. To this are added 1 mole of ethyl malonic acid ester, and then gradually about 1.1 moles of 2-isobutyl bromide. The mixture is gently refluxed for some hours, or until it no longer shows alkaline reaction to moist litmus paper. Most of the alcohol is removed by vacuum distillation, leaving an oily residue. Water is added to this residue to dissolve the sodium bromide; and the oily layer, which is ethyl isopropyl-carbinyl malonic acid ester, is separated and dried. It is purified by fractional distillation in vacuum. When thus purified, ethyl isopropyl-carbinyl malonic acid ester is a colorless or pale yellow liquid, having a boiling point of 103°-105°C at about 4 mm pressure, and a refractive index at 25°C.
3 moles of sodium are dissolved in 10 to 12 times its weight of absolute alcohol under a reflux condenser. To this are added 1.6 moles of urea and 1 mole of ethyl isopropyl-carbinyl malonic acid ester. The mixture is gently refluxed for 2-4 h, after which most of the alcohol is removed by vacuum distillation. The residue is dissolved in water, and a sufficient amount of dilute acid is added to completely precipitate the isopropyl-carbinyl barbituric acid.
The precipitate is filtered off, dried, and recrystallized from dilute alcohol. 1 mole of isopropyl-carbinyl barbituric acid is dissolved in a suitable vessel in a 10%-35% aqueous solution of 1 mole of potassium hydroxide. To this are added somewhat in excess of 1 mole of allyl bromide, and alcohol equal to about 10% of the total volume of the solution. The vessel is agitated for 50- 75 h. At the end of this time, the solution, which may still exhibit two layers, is concentrated to about one-half its volume, to remove the excess allyl bromide and the alcohol. On cooling, an oily layer, which is isopropyl-carbinyl allyl barbituric acid, separates out as a sticky viscous mass. It is dried, washed with petroleum ether, and dissolved in the minimum amount of benzene. Any unreacted isopropyl-carbinyl barbituric acid, which does not dissolve, is filtered off. The addition of petroleum ether to the clear filtrate causes the isopropyl-carbinyl allyl barbituric acid to precipitate as an oily mass. This is separated, washed with petroleum ether, and dried in vacuum.

brand name

Sandoptal (Novartis).

Therapeutic Function

Hypnotic, Sedative

Purification Methods

It can be recrystallised from H2O or dilute EtOH, and sublimes at 100-120o/8-12mm. It is soluble in *C6H6, cyclohexane, tetralin and pet ether at 20o. [Butler et al. J Am Chem Soc 77 1486 1955, Beilstein 24 III/IV 2006.]