4-Amino-3-azido

The 1,3-dipolar cycloaddition of azido-l,2,5-oxadiazoles (azidofurazans) to dicarbonyl compounds has been studied and a new procedure for the synthesis of (l,2,3-triazol-l-yl)-l,2,5-oxadiazoles was proposed <2002MC159>. The cycloaddition of 4-amino-3-azido-l,2,5-oxadiazole 168 to nitriles with activated methylene groups has been studied, and 3-amino-4-(5-amino-l/7-l,2,3-triazol-l-yl)-l,2,5-oxadiazoles 169 and the products of their Dimroth rearrangement 170 have been synthesized <2004MC76>. 

Das bei der Umsetzung von 3,4-Diamino-furazan mit Nitroso-benzol erhaltene 4-Amino-3-phenylazo-furazan (I 27%) liefert mit Blei(IV)-acetat 5-Phenyl-(1,2,3-azeniaazoniaazolo 4,5-c]-furazan) (II 28%)257 258, das auch aus 4-Amino-3-azido-furazan mit Nitroso-benzol zugang-lich ist259 ... 

Das ebenfalls aus 4-Amino-3-azido-furazan mit Anilin bei 150° zugangliche 4-Amino-3-phe-nylazo-furazan reagiert mit Nitrosyl-Verbindungen bei anschlieBender Behandlung mit Azid-Ionen zu 4-Azido-3-phenylazo-furazan. Letzteres liefert in der Warme ebenfalls das Betain I259 ... 

Sowohl bei der Umsetzung von 4-Amino-3-azido-furazan mit Nitrosobenzol als auch durch Erwarmen von 4-Azido-3-phenylazo-furazan wird 5-Phenyl-(1,2J-azeniaazoniaazolo[4,5-c fu-razan) er nalten259 ... 

Heating 4-amino-3-azido-4//-1,2,4-triazoles (229) in chlorobenzene to 110 °C gives the 3-amino-l,2,4,5-tetrazines (232). This reaction is explained by the intermediate formation of the nitrene (230) which opens to the formazane (231) and subsequent ring closure by nucleophilic attack of the hydrazono group on the nitrile function (66TL5369). 

Oxidation of 1,2-diaminobenzimidazole, leading to the formation in high yield of 3-aminobenzo-l,2,4-triazine 838, is thought to proceed through recyclization of an intermediate nitrene 836 (possibly via diazene intermediate 837) as evidenced by the formation of amine 838, with a high efficiency on the thermolysis of l-amino-2-azidobenzimidazole 835. The reaction works well also for other A -amino—azidoimidazoles and 4-amino-3-azido-l,2,4-triazoles. 

Amino-3-azido-5-methyl-s-triazole heated at 110° in chlorobenzene — 3-amino-6-methyl-s-tetrazine. Y 95%. F. e. s. H. H. Takimoto and G. C. Denault, Tetrah. Let. me, 5369. 

In each table, substituted azoles are ordered in the following way alkyl, substituted alkyl, aryl, formyl, acetyl, carboxylic acid, alkoxycarbonyl, cyano, amino, azido, diazonium salt, nitroso, nitro, hydroxy, alkoxy, fluoro, chloro, bromo, and iodo. 

A variety of nucleophiles could also be added to unsaturated ketonucleosides, to afford (by way of a 1,4-addition mechanism) amino-, azido-, aziridino-, and thio-ketonucleosides. The action of metal hydrides on ketonucleosides has been extensively discussed in Section V. 

M. J. Robins, S. D. Hawrelak, A. E. Hernandez, and S. F. Wnuk, Nucleic add related compounds. 71. Efficient general synthesis of purine (amino, azido, and triflate)-sngar nucleosides, Nucleosides Nucleotides 11 821 (1992). 

A virus in both sialidase inhibition and plaque-reduction assays. Alkyl ethers up to twelve carbon atoms in length exhibited similar inhibitory activity to Zanamivir against influenza A virus sialidase, however, showed a pronounced improvement in plaque-reduction assay compared to the parent triol 1. Alkylation of the C-7 hydroxyl with two-carbon substituents bearing terminal hydroxyl, amino, azido, and acetamido groups yielded inhibitors 61-64 and did not significantly affect the binding and had similar potency to that of ethyl or propyl ethers 65 or 66 (Fig. 9). 

Epoxy sugars are frequently used as starting compounds in the synthesis of sugar derivatives (compare Section IV) such as halo, amino, azido, thio, deoxy, and branched-chain derivatives. The oxirane ring is in general more reactive than the oxetane or oxolane ring. It is opened with nucleophiles under base or acid catalysis. On the other hand, the oxirane ring remains unattacked under the conditions of catalytic debenzylation on palladium,... 

Alkylthio-allyl- -dimethylester E19b, 1148 (Carben-C,S-Insetion) (Amino-azido-methylen)- -methylester-nitrile E15/1, 856 (N3 - NH2)... 

Besides ring-chain tautomerism (Section 4.11.4.1.2(0) and the Dimroth rearrangement (Section 4.11.4.1.2(iii)) cleavage reactions of some amino-, azido and diazo-methyltriazoles have been reported. Thus, 5-azido-l,4-diphenyl-l,2,3-triazole (121) proved to be unusually labile above 50 °C. Nitrogen is evolved with the formation of a conjugated nitrile (122) (64JA2025, 70JOC2215). Similarly the diazomethyltriazole (123) decomposes to (124). Both reactions can be explained in terms of concerted processes. 

N, C, H only (20) Amino, azido, imino, cyano, diazonium, guanidino... 

Yielding LW, Yielding KF (1984) Ethidium binding to deoxyribonucleic acid spectropho-tometric analysis of analogs with amino, azido, and hydrogen substituents. Biopolymeis 23(1) 83-110... 

Di-0-mesylthymidine was used as a precursor of 5 -amino-3 -azido-3, 5 -dideoxythymidine (86), the synthetic route involving selective displacement of the 5 -G-mesyl group by azide ion.123 The 2, 3, 5 -tri-0-mesyl derivative of uridine gave the anhydro-azidonucleoside 87 when treated with sodium azide, and this could be converted, via the 2, 3 -/yxo-epoxide, into a mixture of amino-azido nucleosides 88 and 89.124... 

It shows that an epoxide ring is opened stereospecifically with NaNs to azido hydroxy cyclohexene, which undergoes ring closure with TPP to give the corresponding aziridine, and is opened again with NaNs to the amino azido cyclohexene derivative with an exactly defined stereochemistry. This azide function remains in the molecule as a masked amine until the second last reaction step. 

Modification of the 5 -hydroxyl of ddU to the 5 -0-methanephosphonate (ddU-5 -OCH2POjNa2) did not significantly improve the poor activity of Ae parent compound. Replacement of the hydroxyl group at the 5 -position of AzddU by an isocyano substituent greatly diminished activity. Compounds in which the 5 -hydroxyl of 2 -deoxyuridine was substituted by amino, azido, or isocyano moieties were inactive. 

NMR spectroscopy." The results show that the interchange process of the rotational isomers follows first-order kinetics with respect to the forward [ki] and reverse [k i) reactions. Activation parameters [ki, k i, ktotai, Eau Ea-i, Ea(totai), AH and AG ), and thermodynamic parameters Ke, Alf, AG° and AS ) were also obtained experimentally. The synthesis and full characterization of the previously unknown, highly-labile, amino-(azido)phosphenium salt [(Me3Si)2N = P-N3][GaCl4] (30), has been reported. ... 

In an analogous fashion to the hydroboration reaction, a variety of boron-containing substrates react with iminoboranes. Addition of X2B—Cl, X2B—N3, X2B—SR, X2B—NR2, and X2B—R to the unsaturated B—N system is called chloro-, azido-, thio-, amino-, and alkyloboration, respectively. The azidoboration and chloroboration of two iminoboranes are shown ia equations 23 and 24 (72). 

When 6-amino-3-chloropyridazine 1-oxide is diazotized in 50% sulfuric acid, 6-hydroxy-3-pyridazinediazonium anhydro salt is formed. An azido group at either position in pyridazine A-oxides can readily be replaced with sodium alkoxides. 

An unusual approach to the lumazine nucleus was found in the photochemical transformation of 6-azido-l,3-dimethyluracil (289) with various amino compounds (78JA7661). Irradiation of (289) in the presence of ethyl a-amino acid esters forms 7-substituted 7,8-dihydrolumazin-6-ones (288), and with a-aminoketones 6-substituted 7,8-dihydro-lumazines (290) are formed (equation 103). 

The two NH2 stretching vibrations of aminopyrazoles follow the Bellamy-Williams relation [r-jlNH) = 345.5-0.876r <,s(NH)] (76AHC(Sl)l) establishing the amino tautomeric structure of (91). Azidopyrazoles also show the Vs and Vas bands of the azido group. The... 

Amino-3-phenylisothiazole cyclizes on reaction with 2-azido-3-ethylbenzothiazolylium borofluoride to give compound (110) (78HCA108). 4-Aminoisothiazole reacts with 1,4-dibromobutane to give 4-pyrrolidinylisothiazole (80MI41700). 

Furan-2-carbaldehyde, 3-amino-Friedlander synthesis, 4, 648 Furan-2-carbaldehyde, 3-azido-reduction, 4, 647 Furan-2-carbaldehyde, 4-bromo-X-ray diffraction, 4, 543 Furan-2-carbaldehyde, 5-bromo-nucleophilic substitution, 4, 612 reactions... 

Pyridazine, 4-amino-5-formyl-3,6-dimorpholino-synthesis, 3, 346 Pyridazine, 4-amino-3-halo-reaction with potassium amide, 3, 29 Pyridazine, aryl-synthesis, 3, 28 Pyridazine, arylthio-synthesis, 3, 27 Pyridazine, 3-azido-... 

Thiophene, 2-amino-3-cyano-5-phenyl-synthesis, 4, 888-889 Thiophene, 3-amino-4,5-dihydro-cycloaddition reactions, 4, 848 Thiophene, 2-amino-3-ethoxycarbonyl-ring opening, 4, 73 Thiophene, 2-amino-5-methyl-synthesis, 4, 73 Thiophene, 2-anilino-synthesis, 4, 923-924 Thiophene, aryl-synthesis, 4, 836, 914-916 Thiophene, 2-(arylamino)-3-nitro-synthesis, 4, 892 Thiophene, azido-nitrenes, 4, 818-820 reactions, 4, 818-820 thermal fragmentation, 4, 819-820 Thiophene, 3-azido-4-formyl-reactions... 

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