cis-Apovincamine (Vinpocetine USP Related Compound B), is a vinca alkaloid and a chemical precursor of Vinpocetine (V332500), a derivative of Vincamine with vasodilating activity. Vasodilator (cerebral).
Apovincamine is semisynthethetic derivative of (+)-vincamine. Vincamine is
alkaloid of Vinca minor. Alcoloid of Tabernaemontana rigida (Apocynaceae)
also is used as raw material for preparing of apovincamine. (+)- Vincamine
was transformed into oxime ester by reaction with NaNO2 in acetic acid at 0°C
-(+/-)-methyl-3-((12bR)-1-ethyl-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-
a]quinolizin-1-yl)-2-(hydroxyimino)propanoate, which was resolved on the
isomers with dibenzoyl D-tartratic acid. (-)-Methyl 3-((12bR)-1-ethyl-
1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizin-1-yl)-2-
(hydroxyimino)propanoate was re-crystallized from methanol to afford (-)-
methyloxime ester, MP: 195°C.
2 g of above oxime methyl ester was heated in mixture of methanol (37.5 ml)
and conc. H2SO4 (13.5 ml) on water bath for 1 hour. The solution was poured
into ice-water (80 ml), basified with conc. NH4OH to pH 9, and extracted with
CH2Cl2 (3x20 ml). The combined extracts were dried (MgSO4), filtered,
evaporated in vacuum and the residue was re-crystallized from MeOH (5 ml)
to yield 1.32 g (72.5%) of (+)-apovincamine, MP: 160°-162°C.
