Approaches to the synthesis of quinazolino[1,2,3]benzotriazinones

Ahern, Terence Patrick; Fong, Handrick; Vaughan, Keith

doi:10.1139/v76-043

Cited by 7 publications

(3 citation statements)

References 5 publications

(7 reference statements)

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“…( d ) Solvolysis of (7) in aqueous ethanol (20:80) proceeds much faster than in pure ethanol. This observation is consistent with the greater ionising power of the mixed solvent system, and in both cases the product was the pure ethyl ether (9).…”

Section: Bu'ohsupporting

confidence: 84%

Kinetic study of the solvolysis reactions of 1-aryl-3-acetoxymethyl-3-alkyltriazenes: evidence for iminium ion intermediates and the S N1 mechanism

Hemens¹,

Vaughan²

1986

J. Chem. Soc., Perkin Trans. 2

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The first-order rate constants of the reactions of acetoxymethyltriazenes with nucleophiles have been measured. Acetoxymethyltriazenes undergo hydrolysis in phosphate buffer to give the corresponding arylamines, presumably via the hydroxymethyl-and monomethyl-triazenes. The acetoxymethyltriazenes undergo solvolysis in alcohols and in mixtures of alcohols and other solvents; the rate of solvolysis has been correlated with the Grunwald-Winstein parameter (Y) for solvent ionising power, thus supporting the hypothesis of an S,1 mechanism and the intermediate formation of iminium ions during the solvolysis. The hypothesis is further supported by the non-common-ion effect; the presence of lithium chloride in the solvent greatly increases the rate of reaction, whereas lithium acetate causes a slight decrease in rate, attributable to a common-ion effect. Reaction of the acetoxymethyltriazene with sodium azide in aqueous acetone affords the a-azidomethyltriazene (a new type of triazene not previously reported) and provides supporting evidence for the iminium ion hypothesis. On the other hand, the acetoxymethyltriazene did not react with neat ethanethiol, providing further evidence for an S,1 mechanism; and S,2 reaction would be expected to proceed more quickly in the thiol than in the alcohol. It is shown that hydroxymethyltriazenes do not react via iminium ions and that functionalisation to a derivative such as the acetate is necessary for iminium ion generation. The implications of these results for the metabolism of xenobiotic N-alkyl compounds are discussed.

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Section: Bu'ohsupporting

confidence: 84%

Kinetic study of the solvolysis reactions of 1-aryl-3-acetoxymethyl-3-alkyltriazenes: evidence for iminium ion intermediates and the S N1 mechanism

Hemens¹,

Vaughan²

1986

J. Chem. Soc., Perkin Trans. 2

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“…haloethyltriazenes and most studies in this field N=N-NR~ have dealt with monoalkyltriazenes (14,15) and H \ dialkyltriazenes (16,17). We wish to report the ~1 synthesis, characterization, and identification of…”

mentioning

confidence: 99%

“…Syntheses and Properties of Protium and Deuterium Labelled Triazenes The aryl triazenes required in this study were prepared by coupling of the aryl diazonium cation with the 2-haloethylamine (15). The observation that the presence of an electron-withdrawing group in the phenyl ring, particularly at the p-position, increases the stability of the triazene and prevents formation of the pentaazadiene during the reaction of the aryldiazonium ion with the primary amine (18) was exploited in these preparations.…”

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confidence: 99%

Synthesis of 3(2-haloethyl)aryltriazenes and study of their reactions in aqueous solution

Lown¹,

Singh²

1981

Can. J. Chem.

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J. WILLIAM LOWN and RANJIT SINGH. Can. J. Chem. 59, 1347 (1981). Several 1-aryl-3-(2-haloethy1)triazenes have been synthesized and characterized spectroscopically as well as by their esterification of 3,5-dinitrobenzoic acid. Their rates of decomposition in aqueous mediaat pH 7 were determined polarographically employing the electrochemically active triazene moiety. In two selected cases the rates of decomposition increase markedly with lowered pH in the range 9.3 to 4.65. The products of aqueous decomposition, both volatile and involatile, were identified and quantitated by gc and gc-ms. Discrimination between alternative decomposition pathways was possible by the preparation and use of selectively deuterated triazenes. The data are consistent with initial protonation of the triazene and generation therefrom of a 2-haloethyl cation (or its kinetic equivalent) which is subject to rearrangements detected by deuterium scrambling. A second competing pathway involves cyclization of the triazene to a I-aryl-1,2,3-triazoline intermediate which is then subject to nucleophilic opening at two sites with attendant loss of nitrogen. The effects of structural changes in the triazenes on their modes of decomposition and generation of electrophiles should assist in the interpretation of their antitumor effects.On a synthetise plusieurs aryl-1 (halo-2 ethyl)-3 triazenes et on les a caracterises par spectroscopie et en les transformant en leurs dinitro-3,5 benzoates. On adetermink leur vitesse de decomposition en milieu aqueux a un pH = 7 en faisant appel a l a polarographie et en utilisant la portion triazene electrochimiquement active. Dans deux cas selectionnes, les vitesses de decompositions augmentent fortement lorsque le pH diminue de 9,3 B4,65. Faisant appel a la cpg et a la cpgreliee a la sm, on a identifie les produits de decomposition volatils et non-volatils qui se forment en milieu aqueux et on a determine les quantites de produits formes. On peut choisir parmi les diverses voies de decomposition possibles en preparant et en utilisant des triazenes selectivement deuteres. Les donnes sont en accord avec une protonation initiale du triazene conduisant par la suite a la formation d'un cation halo-2 ethyl (ou son equivalent cinetique) qui peut subir des transpositions qui peuvent @tre differencites sur la base des produits deuteres obtenus. Une autre voie qui est en competition avec la precedente fait intervenir la cyclisation du triazene en un intermediaire aryl-1 triazoline-1,2,3 qui peut ensuite subir une ouverture nucleophile par attaque en deux points avec une perte concomittante d'azote. Les effets de changements structuraux dans le triazene sur leurs modes de decomposition et sur la formation d'electrophiles devraient faciliter l'interpretation de leurs effets antitumoraux.[Traduit par le journal]Synthetic attempts to design antagonists of 4-Ccarboxamide (MIC), l c (3), prior to its decompoaminoimidazole-5-carboxamide, the ribotide of sition in water to give electrophiles which are which is a precursor in purine ...

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References

1996

Chemistry of Heterocyclic Compounds: A Series of Monographs

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Approaches to the synthesis of quinazolino[1,2,3]benzotriazinones

Abstract: T. PATRICK AHERN, HANDRICK FONG, and KEITH VAUGHAN. Can. J. Chem. 54, 290 (1976). The synthesis of I-(0-carboxamidopheny1)-3-aryl triazenes 12 and 15 (X = CONH2 and H ) is described. [Tradilit par le journal]

Cited by 7 publications

References 5 publications

Kinetic study of the solvolysis reactions of 1-aryl-3-acetoxymethyl-3-alkyltriazenes: evidence for iminium ion intermediates and the S N1 mechanism

Kinetic study of the solvolysis reactions of 1-aryl-3-acetoxymethyl-3-alkyltriazenes: evidence for iminium ion intermediates and the S N1 mechanism

Synthesis of 3(2-haloethyl)aryltriazenes and study of their reactions in aqueous solution

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