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Canthin-6-one

Similarly, permanganate oxidation of a number of naturally occurring canthin-6-one derivatives (295) leads to j8-carboline-l-carboxylic acid or its methyl ester.A j8-carboline-l-carboxylic acid... [Pg.155]

Canthin-6-one, which is a cytotoxic alkaloid, is synthesized in six steps from harmalane (Scheme 84) <1999TL7075>. The second step is a [4+2] cycloaddition with methyl 2-(dimethylamino)acrylate under singleelectron-transfer electrolysis. [Pg.926]

Snyder and coworkers followed a completely different path to canthin-6-one (Fig. 23). Earlier they had shown that indole-substituted 1,24-triazine 66 could be heated in refluxing triisopropylbenzene (bp = 232 °C) to give /3-carboline 67 via an intramolecular cycloaddition/cycloreversion reaction [58]. Selective oxidation of 67 at C-6 was achieved through the use of triethylbenzylammonium permanganate [59]. Success of the reaction proved to be very sensitive to the solvent chosen. Heating 67 for 4 h at 70 °C in a 5 1 mixture of dichloromethane and acetic acid gave a 65% yield of 63, yet use of increasing amounts of dichloromethane slowed the reaction down (no reaction occurred in pure dichloromethane), while use of pure acetic acid led to an intractable mixture. [Pg.120]

As alluded to earlier, methoxy-substituted canthin-6-ones have also shown antitumor activity, so not surprisingly, there has been interest in the synthesis... [Pg.121]

Canthin-6-ones Ailanthus altissima Brucea javanica... [Pg.200]

Acetyl-3-methoxycarbonyl-/ -carboline, the alkaloid of Vestia lycioides, has been synthesized by two routes 200,6 the second involves the benzylic oxidation-dehydrogenation of l-ethyl-3-methoxycarbonyl-l,2,3,4-tetrahydro-/ -carboline by means of selenium dioxide in dioxan. A by-product in this oxidation was 1 -acetyl-/ -carboline, which occurs in Ailanthus malabarica. An extension of this reaction led to a simple two-stage synthesis of canthin-6-one (22) from Ab-benzyltryptamine and a-ketoglutaric acid (Scheme 2).206... [Pg.170]

The root bark of Ailanthus altissima Swingle contains the known alkaloids canthin-6-one (22), l-methoxycanthin-6-one, canthin-6-one A-oxide, and 1-acetyl-4-methoxy-/ -carboline, together with three new alkaloids, identified as 1-methoxy-canthin-6-one A-oxide, l-(2-hydroxyethyl)-4-methoxy-/ -carboline, and 1(1,2-dihydroxyethyl)-4-methoxy-/ -carboline.21... [Pg.170]

A synthesis of XIV was accomplished as follows (9) /J-carboline-1-carboxylic acid chloride was condensed with the magnesium ethoxy derivative of malonic ester to yield, after acid hydrolysis, 4-hydroxy-canthin-6-one (XV). This compound, with phosphorous oxychloride followed by heating in a sealed tube with potassium methyl mercaptide, gave the alkaloid XIV. If 4-hydroxycanthin-6-one is condensed with phosphorous oxychloride-phosphorous pentachloride, 4,5-dichlorocan-thin-6-one and 4-hydroxy-5-chlorocanthin-6-one are formed. [Pg.252]

Using this methodology, the cytotoxic alkaloid canthin-6-one LXVIIIb has been synthesized in a short sequence with good overall yield [248d]. [Pg.955]

The recently discovered antimicrobial activity of canthin-6-one (12) has provided the impetus for renewed synthetic studies. Of the new, efficient syntheses reported " one involves the direct formation of canthin-6-one by a Doebner reaction on /S-carboline-1 -carboxaldehyde, for which an improved preparation was developed the overall yield of canthin-6-one from tryptophan is 15%. Alternatively, condensation of /S-carboline-1-carboxaldehyde with malonic ester, followed by hydrolysis and decarboxylation of the product, affords canthin-6-one in 19% overall yield from... [Pg.186]


See other pages where Canthin-6-one is mentioned: [Pg.925]    [Pg.119]    [Pg.120]    [Pg.120]    [Pg.120]    [Pg.120]    [Pg.121]    [Pg.121]    [Pg.122]    [Pg.123]    [Pg.242]    [Pg.413]    [Pg.202]    [Pg.262]    [Pg.25]    [Pg.155]    [Pg.249]    [Pg.249]    [Pg.250]    [Pg.250]    [Pg.251]    [Pg.251]    [Pg.252]    [Pg.253]    [Pg.32]    [Pg.62]    [Pg.72]    [Pg.91]    [Pg.91]    [Pg.290]    [Pg.354]    [Pg.164]    [Pg.187]    [Pg.188]    [Pg.135]   
See also in sourсe #XX -- [ Pg.106 ]

See also in sourсe #XX -- [ Pg.250 ]

See also in sourсe #XX -- [ Pg.135 , Pg.137 , Pg.138 , Pg.161 ]

See also in sourсe #XX -- [ Pg.7 , Pg.389 , Pg.390 , Pg.394 ]

See also in sourсe #XX -- [ Pg.7 , Pg.389 , Pg.390 , Pg.394 ]

See also in sourсe #XX -- [ Pg.655 , Pg.662 , Pg.667 ]

See also in sourсe #XX -- [ Pg.226 , Pg.1084 , Pg.1095 ]




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Canthin-6-one alkaloids

Canthine

Canthines

Properties of the canthin-6-ones

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