1-Benzoyl-1,2,4-triazoles

However, it was noted that the discrepancy between the micellar rate constant and the rate constant in the model compound solution was largest for 4, which was known to be more sensitive toward hydrophobic interactions than 5. In addition, the solvatochromic Ex30 probe indicated a much more hydrophobic environment and other authors similarly found systems for which a model solution only mimicking the surfactant headgroups was insufficient to reproduce properties of the micellar pseudophase. The Hammett p-value for hydrolysis of substituted 1-benzoyl-1,2,4-triazoles 6a-f could similarly not be reproduced using a model solution mimicking ionic interactions only. " ... 

It was found that the sensitivity of the hydrolysis of substituted 1-benzoyl-1,2,4-triazoles 6a-f to added 1-propanol and tetramethylammonium bromide varied... 

To correct for nonideal behavior of the 1-propanol and tetramethylammonium at these high concentrations, a further optimization of the mimicking solution was required. A second-order solution for CTAB was elaborated using the first-order solution as a starting point. This second-order solution was found to reproduce not only the micellar rate constants for the hydrolysis of the substituted 1-benzoyl-1,2,4-triazoles 6a-f but the hydrolysis rate constant for 5 and the Ex30 value with good accuracy as well. " ... 

Alkyl (Me, Et, n-Pr, n-Bu), alkyldimethyl, and alkyltrimethylammonium bromides retard the neutral hydrolysis of 1-benzoyl-1,2,4-triazole (190) to benzoic acid and the triazole (191).162 This effect is attributed to a dominant stabilization of the initial state through hydrophobic interactions with the co-solute. The effects of cetylpyridinium bromide on the hydrolysis of 2,4-dinitrochlorobenzene by hydroxide ion in water have been reported.163... 

Noordman, W., Blokzijl, W., Engberts, J.B.F.N. and Blandamer, M.J., Kinetic medium effects of amphiphilic cosolutes below their critical micelle concentration the effect of sodium n alkyl sulfates on the neutral hydrolysis of 1-benzoyl-1,2,4-triazole, J. Org. Chem., 1993,58, 7111-7114. 

Triazole Derivatives. Triazole derivatives are known to possess tumor necrosis factor-a (TNF-a) production inhibitor activity. The synthesis of triazole derivatives can be achieved from alkynes or diynes by a tandem cascade reaction involving 1,3-dipolar cycloaddition, anionic cyclization and sigmatropic rearrangement on reaction with sodium azide. Some of the benzoyl triazole derivatives were considered to be potent local anaesthetics and are comparable with Lidocaine. The triazoles can also be prepared from benzoyl acetylenes,triazoloquina-zoline derivatives, 2-trifluoromethyl chromones, aliphatic alkynes, 2-nitroazobenzenes, ring opening of [ 1,2,4]triazolo [5,1-c] [2,4]benzothiazepin-10 (5//)-one, alkenyl esters and dendrimers. A number of these reactions are outlined in eqs 44 8. 

The triazole 76, which is more accurately portrayed as the nucleophilic carbene structure 76a, acts as a formyl anion equivalent by reaction with alkyl halides and subsequent reductive cleavage to give aldehydes as shown (75TL1889). The benzoin reaction may be considered as resulting in the net addition of a benzoyl anion to a benzaldehyde, and the chiral triazolium salt 77 has been reported to be an efficient asymmetric catalyst for this, giving the products (/ )-ArCH(OH)COAr, in up to 86% e.e. (96HCA1217). In the closely related intramolecular Stetter reaction e.e.s of up to 74% were obtained (96HCA1899). 

Cyclization of the hydrazone derivatives of 4-benzoyl[ 1,2,3]triazole 695 by reaction with one carbon inserting agent such as an orthoester, an aldehyde, a ketone, or a phosgene afforded triazolotriazine 696 or 697 (88JHC743). The newly created C—N bond displays particular sensitivity due to the electron-attracting effect of the triazole ring (Scheme 147). 

Diazonium salts couple to hydroxy-substituted vicinal triazoles (101) with subsequent rearrangement of the hydroxy arylazo compounds (102) to the carbamoyl tetrazole (104).170 An open-chain intermediate (103) has been proposed.169 This rearrangement is similar to that of the benzoyl... 

Results corresponding to those for the substituted N-benzoylimidazoles have been observed for a series of meta- and para-substituted /V-benzoyl-1,2,4-triazoles which, under the same conditions and over the whole range of substituents, show reaction rates about ten times faster than those of the imidazolides.[9],[10]... 

Other non-traditional preparations of 1,2,3-triazoles have been reported. The rearrangement in dioxane/water of (Z)-arylhydrazones of 5-amino-3-benzoyl-l,2,4-oxadiazole into (2-aryl-5-phenyl-27/-l,2,3-triazol-4-yl)ureas was investigated mechanistically in terms of substituents on different pathways <06JOC5616>. A general and efficient method for the preparation of 2,4-diary 1-1,2,3-triazoles 140 from a-hydroxyacetophenones 139 and arylhydrazines is reported <06SC2461>. 5-Alkylamino-] //-], 2,3-triazoles were obtained by base-mediated cleavage of cycloadducts of azides to cyclic ketene acetals <06S1943>. Oxidation of N-... 

The role of substituents X on the mononuclear heterocyclic rearrangement (MHR) of 20 phenylhydrazones 54 of 3-benzoyl-5-phenyl-l,2,4-oxadiazole into the triazoles 55 (Equation 2) has been investigated, allowing the influence of X on the product distribution to be evaluated and first-order rate constants and Hammett correlations to be determined <1999T12885>. 

The reaction of a solution 2-hydrazinobenzothiazoles in DMF with formic acid, benzoyl chloride, or acetyl chloride, in the presence of potassium carbonate, gave the 8-fluoro-9-substituted-[l,3]-benzothiazolo[5,l-3]3-substi-tuted-1,2,4-triazoles in good yield, as shown for 6-fluoro-7-(2 -nitrophenylamino)-2-hydrazinobenzothiazole 395 yielding compound 396 (Equation 75) <2004IJH89>. 

Glycosylation of 3-amino-5(7)//-[l,2,4]triazolo[4,3-3] l,2,4 triazole 17 with 1-O-acetyl- 2,3,5-tri-O-benzoyl-D-ribo-furanose 18 or 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide 19 can be selective or nonselective, depending on the reaction conditions (Scheme 1). In the presence of trimethylsilyl triflate or boron trifluoride etherate, the... 

The syntheses shown in Scheme 26 (71CB1573) are based on dibenzo-/3-tropolone (108) and its enamines. Condensation of 108 and benzoin in the presence of ammonia affords pyrrole 109. The morpholino enamine gives pyrazole 110 via benzoylation, hydrolytic elimination of morpholine, and cyclization, whereas diazo-group transfer onto the anilino enamine leads to triazole 111. Dione 108 and p-nitrophenylazide in one step give predominantly the p-nitro derivative of 111 (92G249). 

In general, acyl azides are too unstable to survive at the temperatures required for addition to acetylenes, although benzoyl azide adds readily to ynamines in toluene. Ethoxycarbonyl azide also gives triazoles in good yield with ynamines. The azide adds to propargylic alcohols in boiling ethanol, and to acetylene at 100° under pressure. Addition to phenylacetylene and to electron-deficient acetylenes has been carried out at 130°. Oxazoles are also formed at this temperature by competing thermal decomposition of the azide, and addition of ethoxycarbonylnitrene to the acetylenes. The triazole obtained from phenylacetylene is 2-ethoxycarbonyl-4-phenyltriazole the two 1-ethoxycarbonyltriazoles can be isolated if the addition is carried out at 50° over several weeks. Since the IH- to -triazole isomerization takes place readily in these systems, a IH-structure cannot be assumed for a triazole formed by addition of these azides. 

A study of the photochemistry of 4-acetyl- and 4-benzoyl-5-methyl-1,2,3-triazoles shows that the nature and lifetime of the lowest triplet state depends on the nature of the 1- and 4-substituents. 4-Benzoyl-5-methyl-1,2,3-triazole has a high rate constant for triplet deactivation, which is attributed to interaction of the nitrogen lone pairs with the excited carbonyl function. The compound forms a pinacol derivative when irradiated in propan-2-ol and undergoes cycloaddition, involving the carbonyl group, with 2-methylpropene, giving an oxetane derivative. 

Iron complexes are reported to be formed from 4-benzoyl- and 4-butyryltriazole and ferrous chloride or nonacarbonyl diiron. The complexes from nonacarbonyl diiron have two triazole molecules per atom of iron, with the iron w-bonded to the ring. 

Reacting this with 1,2,4-triazole in the presence of sodium, followed by the hydrolysis of the protecting benzoyl group with sodium hydroxide gives 2-(2,4-dichlorophenyl)-2-(lH-1,2,4-triazol- l-ylmethyl)-4-hydroxymethyl-1,3-dioxolane... 

Not surprisingly, it is rather difficult to separate the different contributions of the different interactions as they occur in the micellar Stern region. In an attempt to solve this problem, the group of Engberts used a series of hydrolysis reactions of activated esters and amides to probe the reaction environment offered by micelles. The reactions initially involved the water-catalyzed pH-independent hydrolysis reactions of i-methoxy-phenyl dichloroacetate 4 and l-benzoyl-3-phenyl-l,2,4-triazole 5, as extensive information on the rate retarding effects of added cosolutes on this reaction was available. ... 

Thermolysis of 2-phenyl-A-benzoyl-4,5-dimethyl-l,2,3-triazol-l-imine (125) in refluxing DMSO gives 2-phenyl-4,5-dimethyl-1,2,3-triazole (126) and jV,A -diphenylurea (Scheme 20) <92JOC2252>. 

In a photolytic decomposition, triazol-l-imine (125) affords (126), benzamide, A-benzoyl... 

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