Rutaecarpine and Related Alkaloids

Rutaecarpine (63), whose formula is listed in Chart 3, was isolated from Evodia rutaecarpa Hook. f. Thoms, in 1915 by Asatona et al. Significant infrared absorption occurs at 1655 and 3325 cm , uv absorption at 276, 288, 330, 344, and 360 nm, and non-aromatic proton signals in the nmr spectrum at 6 3.23 and 4.60, each two protons (t, J = 7 Hz). 

The action of a solution of potash in amyl alcohol on rutaecarpine produces anthranilic acid and a second acid which, when boiled with hydrochloric acid, is readily decarboxylated to tryptamine (6, 25, 94, 134, 135, 169). A close relationship between rutaecarpine and evodiamine was demonstrated by fusion of isoevodiamine hydrochloride. Rutaecarpine was formed with liberation of chloromethane. A number of syntheses of (63) have been reported 101, 135, 161), including some under so-called physiological conditions. Some of the more recent examples will be mentioned. Kametani et al. 102,108) obtained (63) in 80% yield through a regiospecificH s+n s cycloaddition of a keteneimine (generated in situ by extrusion of sulfur dioxide from the sulfmamide anhydride of anthranilic acid) with 3,4-dihydro-p-carboline or with 1,2,3,4-tetrahydro-l-keto-P-carboline 109) (also called 1,2,3,4-tetrahydronorharman-l-one or, as in Chemical Abstracts, 2,3,4,9-tetrahydro-lH-pyrido[3,4-b]indol-l-one) ac- 

16-Hydroxyrutaecarpine (64) is a constituent of the bark of Euxylophora paraensis Hub. (55) and was also found in Vepris louisii G. Gilbert (12 a). A bathochromic shift in the presence of base evidenced the phenolic nature of the hydroxyl group. The mass spectrum (m/z 169, 168, 167, 155, 115) 

6-Dehydro-16-hydroxyrutaecarpine. Evidence for the location at a double bond between C-5 and C-6 (C-7 and C-8 in the alternative ring numbering system) was obtained from the compound s H-nmr spectrum 

The presence of a formyl group in 14-formyl-dihydrorutaecarpine was suggested by a carbonyl absorption at 1695 cm in the infrared spectrum, as well as by a signal at 8 9.10 in the nmr spectrum. Upon heating with 5% ethanolic KOH, the compound loses formaldehyde to afford rutaecarpine. 

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