Amides 1,2,4-triazole

Chow HF, Lau KN, Chan MC. Click-den-dronized poly(amide-triazole)s-effect of den-dron size and polymer backbone symmetry on self-assembling and gelation properties. Chem A Eur J 2011 17(30) 8395 3. 

Scheme 2 Poly(amide-triazole)s 4-6 prepared from monomers 1 and 2...

Scheme 4 Oligo(amide-triazole) gel 14 formed from the CuAAC copolymerization of monmners 12 and 13 in the presence of a LMWG 10 and a photoactive compound 11...

Scheme 6 Dendronized poly(amide-triazole)s 18 from the CuAAC polymerizatirai of AB monomers 19...

Scheme 7 Dendronized poly(amide-triazole)s 20 from the CuAAC copolymerization of AA 21 and BB monomers 22 (the arrows show the relative arrangement of the triazole dipoles along the...

Cyanopyrazole is obtained from treatment of 4-amino-3-halopyridazines with potassium amide in liquid ammonia, while 4-amino-3,6-dihalopyridazines are rearranged under the same conditions to 3-cyanomethyl-l,2,4-triazole. 

Triazole has been prepared by the oxidation of substituted 1,2,4-triazoles, by the treatment of urazole with phosphorus pentasulfide, by heating equimolar quantities of formyl-hydrazine and formamide, by removal of the amino function of 4-amino-l,2,4-triazole, by oxidation of l,2,4-triazole-3(5)-thiol with hydrogen peroxide, by decarboxylation of 1,2,4-triazole-3(5)-carboxylic acid, by heating hydrazine salts with form-amide,by rapidly distilling hydrazine hydrate mixed with two molar equivalents of formamide, i by heating N,N -diformyl-hydrazine with excess ammonia in an autoclave at 200° for 24 hours, and by the reaction of 1,3,5-triazine and hydrazine monohydrochloride. ... 

The conversion of a 4-arylazo-5-oxazolone into a 1,2,4-triazole by reaction with a Grignard reagent is mentioned in Section II, B, 3. In HiTnilar fashion, the rearrangement of compound 30 to derivatives of 3-carboxy-l,5-diphenyl-lfl -l,2,4-triazoles (40) proceeds readily in the presence of strong nucleophiles [Eq. (26)]. This transformation undoubtedly occurs by ring opening and dehydrative cychzation, and, indeed, the acyclic amide and hydrazide 41 have been isolated. ... 

Triazoles have been obtained via microwave-assisted [3-i-2] cycloaddition, under solvent-free conditions [54], starting from organic azides and acetylenic amides at 55 °C for 30 min (Scheme 23). The complete conversion of the reagents into AT-substituted-1,2,3-triazoles 69 was achieved without decomposition and side products. A control reaction carried out at the same temperature in an oil bath did not give the cycHc products, not even after 24 h of reaction time. 

More recently, Williams has described the one pot synthesis of 2-substituted oxazoles 11 by the thermolysis of triazole amides 9 the reaction does not proceed photo-chemically.<92TL1033> Although the reaction does not involve addition to a nitrile, it is an interesting application of a diazo compound since the proposed zwitterionic intermediate 10 is a resonance form of a diazo imine, so formally the reaction may be thought of as a thermal decomposition of a diazo imine (Scheme 6). 

Finally, NHC complexes of copper, formed in situ from the hnidazolium salt and CuBr have been used in the monoarylation of aniline [167]. Trinuclear Cu(I) catalysts have been applied to the arylation of pyrazoles, triazoles, amides and phenols [168] (Scheme 6.50). 

Hydroxyenones have also been used in catalytic amide formation, although 1,2,4-triazole is required as a co-catalyst. Assumed protonation of the Breslow intermediate and tautomerisation generates an acylazolium intermediate, which is trapped by triazole, releasing the NHC and generating the acyltriazole 60 that is the active acylating agent for the amine (Scheme 12.11) [16]. 

Kellum [115] has described a class-selective oxidation chemistry procedure for the quantitative determination of secondary antioxidants in extracts of PE and PP with great precision (better than 1 %). Diorgano sulfides and tertiary phosphites can be quantitatively oxidised with /-chloropcroxybenzoic acid to the corresponding sulfones and phosphates with no interference from other stabilisers or additives. Hindered phenols, benzophenones, triazoles, fatty acid amides, and stearate... 

The compounds referred to as azolides are heterocyclic amides in which the amide nitrogen is part of an azole ring, such as imidazole, pyrazole, triazole, tetrazole, benzimidazole, benzotriazole, and their substituted derivatives. In contrast to normal amides, most of which show particularly low reactivities in such nucleophilic reactions as hydrolysis, alcoholysis, aminolysis, etc., the azolides are characterized by high reactivities in reactions with nucleophiles within the carbonyl group placing these compounds at about the same reactivity level as the corresponding acid chlorides or anhydrides. 11... 

Tandem azidination- and hydroazidination-Hiiisgen [3 +2] cycloadditions of ynamides are regioselective and chemoselective, leading to the synthesis of chiral amide-substituted 1,2,3-triazoles <06OBC2679>. A series of diversely l-substituted-4-amino-l,2,3-triazoles 132 were synthesized by the copper-catalyzed [3+2] cycloaddition between azides 130 and ynamides 131 <06T3837>. 

Figure 18.11 NHS-PEG4-azide can be used to modify an amine-containing molecule to create an amide derivative terminating in azido groups. The azide modifications then can be used in a click chemistry reaction that forms a triazole linkage with an alkyne-containing molecule. Alternatively, the azide derivative can be used in a Staudinger ligation reaction with a phosphine derivative, which results in an amide bond linkage.

The 1,3-dipolar cycloaddition of azides to alkynes is a versatile route to 1,2,3-tri-azoles. Different combinations of substituents on the azide and on the alkyne allow the preparation of diverse N-substitutcd 1,2,3-triazoles. Katritzky and Singh have described the synthesis of C-carbamoyl-1,2,3-triazoles by microwave-induced cydoaddition of benzyl azides to acetylenic amides (Scheme 6.220) [393]. Employing equimolar mixtures of the azide and alkyne under solvent-free conditions, the authors were able to achieve good to excellent isolated product yields by microwave heating at 55-85 °C for 30 min. In general, the triazole products were obtained as mixtures of regioisomers. Control experiments carried out under thermal (oil bath)... 

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