Sinecod,Hommel,Switz.,1967
Anxiolytic, Muscle Relaxant
Butamirate Citrate is a novel antitussive drug. It is used for the symptomatic treatment of non-productive (dry) cough.
18.2 grams of α-phenylbutyric acid chloride are dissolved in 25 ml of toluene.
To this solution, there is slowly added a solution of 16.1 grams of
diethylaminoethoxyethanol in 25 ml of toluene, the reaction mixture thereby
becoming hot. It is then heated for 8 hr under reflux. The reaction mixture,
after cooling, is carefully poured onto 75 grams of ice and made alkaline with
dilute ammonia. After thorough shaking of the solution, the toluene layer is
removed and washed until neutral with water. The toluene solution is treated
with carbon and dried over sodium sulfate. The toluene is distilled off from the
filtered solution.
The residue is α-phenylbutyric acid diethylaminoethoxyethyl ester. The basic
ester is purified by distillation in a high vacuum. 10 grams of ester are added
to a solution of 7 grams of citric acid in 30 ml of warm acetone. After standing
for some time, the citrate of the ester crystallizes out. After suction filtration and washing with acetone the ester citrate is recrystallized from acetone. The
melting point of the citrate is 75°C.
Butamirate citrate is a non-opioid antitussive with a central effect on receptors in the brain stem. It has also been reported that it reduces bronchospasm with peripheral effect and has anti-inflammatory and anticholinergic effects. Therefore, it is thought to be effective in cough with both acute and chronic etiology.
