5-ALLYL-5-[1-METHYLBUTYL]-2-THIOBARBITURIC ACID Property

Melting point:

132-133°

Density 

1.1828 (rough estimate)

refractive index 

1.5510 (estimate)

pka

7.01±0.40(Predicted)

Water Solubility 

1.298g/L(25 ºC)

Safety

Hazard Codes 

T

Risk Statements 

23/24/25

Safety Statements 

36/37/39-45

RIDADR 

3249

WGK Germany 

3

HazardClass 

6.1(b)

PackingGroup 

III

Toxicity

An ultra-short-acting barbiturate anesthetic that is used in conjunction with inhalational anesthetics. It acts on the barbiturate-binding site in the GABA receptor complex. Excessive doses cause respiratory depression, apnea, or hypotension. Therapy includes establishing and maintaining airway, supporting the circulation, and administering oxygen.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

5-ALLYL-5-[1-METHYLBUTYL]-2-THIOBARBITURIC ACID Chemical Properties,Usage,Production

Description

Thiamylal, 5-allyl-5-(1- methylbutyl)-2-thiobarbituric acid, The sodium salt , Mr 276.36, is an amorphous powder soluble in water. It is prepared by condensation of thiourea with a malonic ester , .

Originator

Surital,Parke Davis,US,1951

Uses

Thiamylal is a barbiturate derivative with sedative, anticonvulsant and hypnotic effects. Thiamylal is used for induction in surgical anaesthesia as well as an anticonvulsant to counteract side effects from other anaesthetics. Thiamylal is a Controlled Substance.

Definition

ChEBI: A member of the class of barbiturates that is 2-thioxodihydropyrimidine-4,6(1H,5H)-dione substituted by a pentan-2-yl and prop-2-en-1-yl group at position 5.

Manufacturing Process

In 450 cc of methanol is added 47 grams of sodium metal and the mixture allowed to completely react to form a methanol solution of sodium methoxide. The methanol solution of sodium methoxide is then cooled to 60°C and 68 grams of thiourea which has been thoroughly dried is added with stirring until a uniform solution is formed. Thereafter, 157 grams of diethyl allyl-(1- methylbutyl)malonate is added to the solution of the sodio derivative of thiourea at a temperature of 55°C and the condensation reaction mixture maintained at the said temperature for 24 hours. Methyl alcohol is removed under vacuum during the course of the reaction while maintaining a temperature of 55°C.
The viscous reaction mixture is then poured into 1.5 liters of ice water and agitated to form a uniform solution. The solution is treated with activated carbon and filtered. Thereafter, 80% acetic acid is added until the filtered solution remains acidic to litmus. The precipitate formed is filtered and washed thoroughly with distilled water. The product is air-dried at a temperature of 95° to 100°C for 48 hours to yield 133 grams of 5-allyl-5-(1- methylbutyl)-2-thiobarbituric acid having a melting point of 132° to 133°C and assaying at 99.5% pure, from US Patent 2,876,225.

Therapeutic Function

Anesthetic