Study on the Synthetic Process of Urapidil Hydrochloride
With 3-[(tert-butoxycarbonyl)amino]propanoic acid(2)and 1-(2-methoxyphenyl)piperazine hydrochloride(3)as starting materials,tert-butyl[3-[4-(2-methoxyphenyl)piperazin-1-yl]-3-oxopropyl]carbamate(4)was obtained by active ester method.3-[4-(2-Methoxyphenyl)piperazin-1-yl]propylamine trihydrochloride(6 hydrochloride)was prepared by the reduction of 4 followed by removing the Boc protective group.Finally,6 was condensed with 6-chloro-1,3-dimethylpyrimidine-2,4(1H,3H)-dione(7)to obtain the title compound with an overall yield of above 61.2％(based on 2)and a purity of 99.95％.The target product was confirmed by HPLC,1H NMR,13C NMR,MS and elemental analysis.The improved process is suitable for industrial production as it solves the technical problem of localization of key intermediate 6.
NETL
NSTL
万方数据
