1.2.3- Triazole-4,5-dicarboxylic acid

A structurally rather dissimilar pTyr mimic was developed by the Boehringer Ingelheim group, namely a triazole-dicarboxylic acid derivative 31 [130], which was shown to yield highly active Lck SH2 domain antagonists. 

Glycosyl azide 121 bearing an additional cyano group at C-1, easily prepared from the 1-bromo-glycosyl cyanide 120 [120], was transformed (Scheme 31) into the triazole-dicarboxylic acid derivative 122 by... 

Triazole-4,5-dicarboxylic acid, 2-(tributylstannyl)-, diethyl ester... 

Bis(3,4-diethyl-2-pyrrolylmethyl)-3,4-dietliyl-l//-pyrrole (2), prepared in situ from the di-t-butylester of the 5,5 -dicarboxylic acid (/), reacts with 4//-1,2,4-triazole-3,5-dialdehyde (3) in di-chloromethane in the presence of trifluoroacetic acid and 2,3-dichloro-5,6-dicyano-/)-benzoquino-ne as an oxidation reagent. Dark blue crystals are obtained after chromatographic purification. The dark violet chloroform solution fluoresces purple at 360 nm and gives the NMR experiments 39. Which compound and which tautomer of it has been formed ... 

Oxidation of benzotriazoles and other fused triazoles by potassium permanganate is a well-established route to lif-triazole 4,5-dicarboxylic acid derivatives. Many of the triazolo[d]pyrimidines, synthesized as purine analogs, can be degraded to monocyclic triazoles by acidic or basic hydrolysis (in other triazolopyriraidines, however, the triazole ring is cleaved preferentially ), e.g. Scheme 24. 

Most 1,2,3-triazolecarboxylic acids lose carbon dioxide when heated above the melting point. These reactions are often useful for the preparation of simpler triazoles, for example, in the synthesis of 1-vinyl-triazoles by decarboxylation of the corresponding 4-carboxylic acids. 4,5-Dicarboxylic acids normally lose 2 moles of carbon dioxide on heating above the melting point this is so, for example, with the u-triazole and with the 1-benzyltriazole but l-phenyltriazole-4,5-dicarboxylic acid preferentially decarboxylates at the 5-position, giving the 4-carboxylic acid. 6-Methyl-l-phenyl-4-carboxylic acid is reported to be de-carboxylated slowly in boiling benzene. ... 

UV irradiation of 2-arylbenzotriazoles (144), including the commercially available photostabilizer Tinuvin P, in an aerated solvent results in oxidation of the benzo ring to give the 2-aryl-l,2,3-triazole-4,5-dicarboxylic acid (146), possibly via the intermediate 2-arylbenzotriazole-4,7-dione (145) (Scheme 25). Indeed, when the independently synthesized l-phenyl-2. -benzotriazole-4,7-dione (145, R = = H) is irradiated under the same conditions, compound (146 R = R = H) is formed, and... 

Azimidol-4,5-dicarboxylic Acid or 1 -Hydroxy-1, 2,3-triazole-4,5-dicarboxylic Acid [called 1-Oxy-1,2.3-triazol-dicarbonsaure-(4,5) in Ger], See under Triazoles... 

Only the 1-benzyl-vic-triazole, crysts(from eth at 20°), mp 61°, appears to have been prepd and reported in the literature. Curtius Raschig(Ref 2) prepd 1-benzyl-vic-triazole by the reaction of benzyl azide with the methyl ester of acetylene-dicarboxylic acid, followed by sapon and decarboxylation. Wiley et al(Ref 3) prepd the compd directly and in better yield from acetylenedicar-boxylic acid, followed by decarboxylation to 1 -benzyl-vic-triaZole(77% yield)... 

Crysts with % HaO(from w), decomp at 182—3° when heated rapidly. Can be prepd by prolonged heating of 4 amino-1,2,4-triaZole-3,5 dicarboxylic acid with coned KOH on a water bath... 

The synthesis and properties of chelate resins containing l,2,3-triazole-4,5-dicarboxylic acid as an anchor group have been described. The 2-vinyltriazole (431) was copolymerized with divinylbenzene to yield crosslinked products and then saponified to give CO2H-containing resins. These can be used for the complexation of heavy metals <79Mi4iioo). 

B. MacPhee, J.M. Guzman, H.R. Almarsson, O. Crystal engineering of novel cocrystals of a triazole drug with 1,4-dicarboxylic acids. J. Am. Chem. Soc. 2003,125, 8456-8457. 

More recently published ideas include the formation of solid derivatives of alkyl azides by treatment with acetylene dicarboxylic acid to form 1-alkyl-triazole-4,5-dicarboxylic acids. These frequently form hydrates with poor melting points and generally poor analytical properties. Alternatively, one can obtain bicyclic fused-ring triazolines by treatment with norbornadiene or dicyclopentadiene °. 

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