ISOEMETINE

Description

This stereoisomer of emetine (q.v.) occurs in minute quantities in Cephaelis Ipecacuanha although it is more conveniently obtained by the reduction of psychotrine (q.v.) followed by methylation of the isocephaeline formed. The alkaloid crystallizes as the monohydrate from Et20 in plates of radiating needles and has [0:]0 - 47.4° (CHC1 3). It is readily soluble in most organic solvents with the exception of petroleum ether and it is also insoluble in H20. It yields several crystalline salts and derivatives, e.g. the dihydrochloride, m.p. 310°C (dec.); dihydrobromide, m.p. 21S-220°C; dioxalate pentahydrate, m.p. 92-SoC; the N-methyl derivative, m.p. lS2-3°C; [0:]0 - SOo (CHC13) and the N-benzoyl compound, m.p. 207-8°C; [0:]0 + 48.9° (CHC13). When oxidized with iodine in EtOH, the alkaloid yields O-methylpsychotrine, while more vigorous oxidation with FeC13 results in the formation of rubremetine, characterized as the hydro_x0002_chloride hexahydrate, brilliant red needles, m.p. 127-8°C.

References

Pyman et al., J. Chern. Soc., 111,439 (1917) Pyman et al., ibid, 113, 226 (1918) Pymanetal., ibid, 1068 (1927)