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
