Showing papers on "Triazene published in 1985"

Triazene metabolism. IV. Derivatives of hydroxymethyltriazenes: potential prodrugs for the active metabolites of the anti-tumour triazene, DTIC.

Abstract: A series of derivatives of the anti-tumour hydroxymethyltriazenes have been investigated for activity in vivo and in vitro. Acetoxymethyltriazenes are active in vivo against the TLX5, P388 and PC6 tumours in mice, and inhibit the growth of TLX5, Np and Li cells in vitro without metabolic activation. The acetoxymethyltriazenes are comparable with the hydroxymethyltriazenes and monomethyltriazenes in their spectrum of activity and thus appear to be prodrugs for these species. On the other hand, a methoxymethyltriazene was found to be active on the TLX5 tumour in vivo, but did not inhibit the growth of Np cells in vitro. This latter observation is consistent with the anticipated chemical stability of the methoxymethyltriazene and the requirement for metabolic O-demethylation to generate an active species. Acetoxymethyltriazenes do not require metabolic intervention and break down chemically in phosphate buffer to the hydroxymethyltriazene, which in turn loses formaldehyde to give the incipient methylating agent, the monomethyltriazene.

Silyl, Germyl, and Stannyl Derivatives of Azenes, NnHn Part II. Derivatives of Triazene N3H3, Tetrazene N4H4, and Pentazene N5H51

Abstract: Publisher Summary This chapter discusses the preparation and properties of silyl, germyl, and stannyl derivatives of azenes N n H n ( n=2–5) Triazenes can be prepared by three methods: redox reactions, building or splitting of nitrogen chains, and exchange of substituents Oxidation of silylated hydrazines provides an easy approach to silylated diazenes Exchange of a triazene-bound substituent by another substituent provides an important method for the synthesis of Group IV derivatives of triazene Tetrazenes can be prepared by the two methods: building of nitrogen chains and exchange of substicuerats An exchange of a tetrazene-bound substituent by another substituent is an, especially important and versatile technique for the synthesis of Group IV derivatives of tetrazene Group IV derivatives of triazene and organyltriazenes are sometimes obtained colorless, sometimes yellow to red The known acyclic silylated, germylated, and stannylated tetrazenes and alkyltetrazenes generally exhibit 2-tetrazene constitution Oxidation of Group IV derivatives of tetrazenes (Me 3 E) 4 N 4 with halogens occurs faster with increasing oxidizing potential and depends on E in the sequence Si 5 H 5 , the cyclic compound 78 is, so far, the only other Group IV derivative of this hydride

Triazene metabolism. V. Chemical and biological properties of N,N-bis-[(1-aryl-3-methyltriazen-3-yl)-methyl]-methylamines: potential prodrugs for the cytotoxic monomethyltriazenes.

Abstract: N,N-Bis-[(1-aryl-3-methyltriazen-3-yl)-methyl]-methylamines, 'bistriazenes', have anti-tumour activity against the TLX5 and PC6 mouse tumours and inhibit the growth of tumour cells growing in culture, without metabolic activation. The biological activity of the bistriazene appears to derive from facile hydrolysis to the cytotoxic monomethyltriazene, Ar-N = N-NHMe, and it is suggested that the bistriazene may be a good prodrug from for the 'active' metabolite of the anti-tumour dimethyltriazene, Ar-N-N = N-NME2. A kinetic study of the bistriazene hydrolysis shows that the reaction is retarded by electron-withdrawing substituents in the aryl group. The results can be interpreted by a mechanism in which the bistriazene behaves as an 'animal' (i.e. N-CH2-N) and undergoes anchimerically assisted fragmentation, via an iminium ion intermediate, to the monomethyltriazene.

Synthesis of radioiodinated analogs of 2-phenylpyrazolo[4,3-c]-quinolin-3 (5H)-one by a modified triazene method

Abstract: No-carrier-added 2-(4-[131I]iodophenyl)- and 8-[131I]iodo-2-phenylpyrazolo[4,3-c]quinolin-3(5H)-one were prepared in isolated radiochemical yields of 11.6 and 5.4%, respectively, by acid decomposition of aryl triazenes in acetonitrile. A modified triazene method involving solid-phase decomposition reactions increased the isolated radiochemical yields to 15–35%.

Triazene Derivatives of Cytisine

Abstract: Die Aryldiazoniumsalze (I) reagieren mit Cytisin (II) im alkalischen pH-Bereich zu den Triazenen (III ).

Preparation and properties of novel trisubstituted N-nitrosoureas which decompose to afford triazenes and nitro compounds under mild conditions

Abstract: 3, 3-Diethyl-(IIa, b) and 3-methyl-3-(3-pyridylmethyl)-1-nitroso-1-tolylureas (IIc, d) were prepared from the corresponding ureas (Ia-d). 3, 3-Dialkyl-1-(2-tolyl) nitrosoureas (IIa, c) decomposed to produce 3, 3-dialkyl-1-(2-tolyl) triazenes (IIIa, c) at room temperature. On the other hand, 3, 3-dialkyl-1-(4-tolyl) ureas (IIb, d) gave mainly the corresponding triazenes (IIIb, d) in protic solvents, although IIb, d gave 3, 3-dialkyl-1-(2-nitro-4-tolyl) ureas (IVb, d) and the denitrosated products (Ib, d) in chloroform or carbon tetrachloride.

A new rapid, regiospecific synthesis of 15-(p-[123I]iodophenyl)pentadecanoic acid

Abstract: The triazene derivative of 15-(p-aminophenyl)pentadecanoic acid, 1-[4-(15-oxopentadecanoyl)phenyl]-3,3-(1,5-pentanediyl)triazene, has been sythesized as a new substrate which is readily converted to 15-(p-iodophenyl)-pentadecanoic acid (IPP). Iodine-123-labeled IPP is prepared in ∼30% yield in less than 30 min by reaction of the triazene with no-carrier added H123I, obtained by decay of123Xe. This rapid, regiospecific synthesis represents as improved method for the preparation of [123I]IPP.

Ligand redistribution in triazene 1-oxide complexes: a voltammetric study

Abstract: Etudes par voltammetrie cyclique et par voltammetrie a impulsions differentielles des reactions des complexes des metaux de transition avec les derives a des triazene oxyde-1 abreges sous la forme M(RX) p avec M=Cu, p=2, M=Co, Fe, Ru et p=3; R=Et, Ph; X=OMe, Me, H, Cl, CO 2 Et, No 2

Triazene derivatives of cytisine

Abstract: Die Aryldiazoniumsalze (I) reagieren mit Cytisin (II) im alkalischen pH-Bereich zu den Triazenen (III ).