Prepn. of apovincaminic acid ester(s) - by azeotropic dehydration of vincamic or epi-vincaminic acid ester(s); useful at hypotensives and vasodilators
摘要
<p>Prepn. of (+)- or (2)-apovincamic acid esters of formula (I) is carried out by dehydrating a (+)- or (-)-vincamic acid ester of formula (II) or a (+)- or (-)-epivincamic acid ester of formula (III); (where R is 2-6C alkyl). Dehydration is effected in a water-immiscible solvent which forms an azeotropic mixt. with H2O, in the presence of a strong organic acid which as a dissociation constant of >=10-2, does not conform an azeotropic mixt. with H2O and has a low vapour pressure at the reaction temp. The H2O formed in the reaction is continuously removed by azeotropic distn. Cpds. (I) are useful as hypotensives and vasodilators. The process gives practically quantitative yields of high-purity (I) free of (II) or (III).</p>
申请公布号
FR2468605(A1)
申请公布日期
1981.05.08
申请号
FR19790026823
申请日期
1979.10.30
申请人
RICHTER GEDEON VEGYESZETI GYAR
发明人
CSABA SZANTAY, LAJOS SZABO, GYORGY KALAUS, JANOS KREIDL, JOSZEF FELMERI, HEDVIG BOLCSKEI, JENONE FARKAS, ANDRAS NEMES, BELA BENKO ET PETER TURCSANYI