34661-75-1

Ebrantil,Byk Gulden,W. Germany,1978

antihypertensive

ChEBI: Urapidil is a member of piperazines.

20.6 g (0.083 mol) of N-(o-methoxyphenyl)-N'-(3-aminopropyl)-piperazine and 15.7 g (0.09 mol) of 1,3-dimethyl-4-chlorouracil were boiled for 15 hours in 100 ml triethylamine. The excess triethylamine was then distilled off in vacuo and the residue was dissolved in 300 ml 1 N hydrochloric acid with subsequent filtration. The filtrate thus obtained was cooled with ice and 2 N aqueous ammonic solution was slowly added with stirring. As soon as the first precipitation appeared, a few crystals of the desired product were added to the solution. The ammoniacal suspension was stirred for one more hour, the precipitate filtered off by suction and washed with 200 ml water.
The material was purified by recrystallization from ethanol with the addition of activated carbon. In this manner 242 g 1,3-dimethyl-4-[γ-[4-(o_x0002_methoxyphenyl]-piperizinyl-(1)]propylamino] uracil having a melting point of 156°C were obtained corresponding to a yield of 75%. The purification may also be effected by boiling the material in acetone to result in similar yields.

Hypotensive