- Triazene Drug Metabolites. Part 5. A Simple Direct Synthesis of 3-Alkoxymethyl- and 3-Alkylthiomethyl-1-aryl-3-alkyltriazenes from 1-Aryl-3-hydroxymethyl-3-alkyltriazenes.
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Reaction of 1-aryl-3-hydroxymethyl-3-methyltriazenes with an alcohol in the presence of hydrogen chloride under anhydrous conditions gives rise to the corresponding 1-aryl-3-alkoxymethyl-3-methyltriazenes in excellent yield.The reaction is acid catalysed and probably proceeds through a triazenyliminium ion.Alkylthio derivatives can also be formed from thiols, but the synthesis fails for both amines, and alcohols containing an amino group.
- Iley, Jim,Rosa, Eduarda,Fernandes, Leonor
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p. 2216 - 2229
(2007/10/02)
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- Kinetic Study of the Solvolysis Reactions of 1-Aryl-3-acetoxymethyl-3-alkyltriazenes: Evidence for Iminium Ion Intermediates and the SN1 Mechanism
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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 SN1 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 α-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 SN1 mechanism; and SN2 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.
- Hemens, Chantal Marie,Vaughan, Keith
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- OPEN-CHAIN NITROGEN COMPOUNDS. PART V. HYDROXYMETHYLTRIAZENES: SYNTHESIS OF SOME NEW ALKYL HOMOLOGUES OF THE ANTI-TUMOUR 3-METHYL-3-HYDROXYMETHYLTRIAZENES AND PREPARATION OF THE DERIVED ACETOXYMETHYL-, BENZOYLOXYMETHYL-, AND METHOXYMETHYLTRIAZENES
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The synthesis of some new 1-aryl-3-alkyl-3-hydroxymethyltriazenes is described.The method of coupling a diazonium salt with an alkylamine/formaldehyde mixture has been extended to (a) some diazonium ions with para substituents other than -M groups, (b) those with substituents in ortho position, and (c) to homologous alkylamines (e.g. ethylamine, propylamine, etc.).Hydroxymethyltriazenes can also be prepared by the reaction of a 1-aryl-3-methyltriazene with formaldehyde.Several new derivatives of hydroxymethyl function have been prepared.Reaction with acetic anhydride or benzoyl chloride in pyridine affords respectively the acetoxymethyl- and benzoyloxymethyl-triazenes; the acetates and benzoates react readily with methanol to give the novel methoxymethyltriazenes.This is the first report of a series of dialkyltriazenes with an ether linkage in the α position. An ether of this type has also been obtained directly from the diazonium fluoroborate salt by coupling with a mixture of benzylamine and formaldehyde in ethanolic solution.
- Hemens, Chantal M.,Manning, Hartford W.,Vaughan, Keith,LaFrance, Ronald,Tang, York
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p. 741 - 748
(2007/10/02)
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