Description
One of the alkaloids from the bark of Cephaelis Ipecacuanha (Brot.) A. Rich,
this base is best crystallized from aqueous solvents when it forms colourless
prisms of the tetrahydrate which show a pale blue fluorescence. The alkaloid is
sparingly soluble in H20, Et20 or C6H6 but dissolves freely in CHCI3, EtOH or
Me2CO. The hydriodide forms microscopic yellow needles from dilute HI, m.p.
200-222°C; the nitrate has m.p. 184-7°C; the sulphate trillydrate forms pale
yellow scales, m.p. 214-7°C; [α]
D + 39.2° (H20); the acid oxalate, colourless
needles which soften at 130°C and melt up to 14SoC, and the dibenzoyl derivative which is an amorphous powder, m.p. 132-SoC after sintering at 120°C.
Three methoxyl groups, an ethyl group and a phenolic hydroxyl group are
present. The methyl ether yields colourless prisms from Et20, m.p. 123-4°C;[α]
D + 43.2° (EtOH) and furnishes a hydrobromide, m.p. 190-200°C; [α]
D +
48° (H20); a sulphate heptahydrate, m.p. 247°C and a picrate, softening at
142°C and melting up to 175°C. The alkaloid gives a red-brown colour with
FeCl3 turning to a bluish-black, while with sulphomolybdic acid it gives a green
colour. It couples with p-nitrodiazobenzene giving an alkali-soluble purple dye.
References
Paul, Cownley., Pharm. J., 25, 111,641,690 (1895)
Paul, Cownley., ibid, 26,321 (1896)
Hesse., Annalen, 405,34 (1914)
Pyman.,J. Chem. Soc., 111,431 (1917)
Brindley, Pyman., ibid, 1067 (1927)
Openshaw, Wood., ibid, 391 (1952)
Synthesis:
Teitel, Brossi., J. Amer. Chem. Soc., 88, 4068 (1966)
