80-50-2

Valpin,Endo (Du Pont),US,1963

Anisotropine Methylbromide is a antichloindergic agent and has been used for relief of gastrointestinal spasm and for the suppression of gastric acid secretion. Anisotropine Methylbromide was found to be potentially useful in the treatment of duodenal ulcer disease.

ChEBI: A quaternary ammonium salt resulting from the reaction of the amino group of anisotropine with methyl bromide.

Preparation of Di-n-propyl acetyl tropine hydrochloride: Tropine (11.12 grams) was dissolved in 100 ml of anhydrous pyridine and to this solution was added 15.64 grams of di-n-propyl acetyl chloride. The mixture was refluxed for 6 hours. This solution was then cooled and the pyridine removed in vacuum. The residue was dissolved in chloroform. The chloroform solution was washed with 10% hydrochloric acid to remove the residual trace of pyridine. The hydrochloride of the product ester is soluble in chloroform and is not extracted from chloroform by hydrochloric acid. This is an unexpected property.
The chloroform solution of the hydrochloride was dried over anhydrous calcium sulfate, and evaporated to dryness, leaving a semisolid residue of product ester hydrochloride. This was recrystallized from chloroform-hexane mixture, MP 186°C.
Preparation of the Anisotropine Methyl Bromide: To the acetone solution of the free base was added an acetone solution, containing an excess of methyl bromide. Within a few minutes the methobromide started to crystallize. The mixture was allowed to stand for several hours. The crystallized solid was filtered, and additional product was obtained by evaporation of the filtrate. The yield was nearly quantitative. After recrystallization from acetone, the product melted at 329°C.

Valpin (Endo).

Anticholinergic