40796-97-2

Bemesetron,Merrel Dow

Anti-emetic.

Tropine (34.24 g) is treated with anhydrous diethyl ether and ethereal hydrogen chloride and the precipitated hydrochloride is isolated by evaporation of the solvent. 3,5-Dichlorobenzoylchloride (51.7 g) is added and the mixture stirred at 140°C for 15 minutes during which time the mixture liquifies, evolves hydrogen chloride gas and resolidifies. After heating for a further 15 minutes the cooled solid is dissolved in water, an excess of an aqueous solution of potassium carbonate is added, and the base is extracted with ethyl acetate. Evaporation of the dried ethyl acetate solution yields a solid, which is recrystallized from aqueous methanol to yield 3,5- dichlorobenzoic acid 8-methyl-8-aza-bicyclo[3.2.1]oct-1-yl ester (endo). MP: 95°C (51.8 g).

Serotonin antagonist

5-HT 3 antagonist.

Store at RT