1.2.3- Triazole 4-hydroxy-2-phenyl

H-1, 2,3-Triazol 4-Hydroxy-2-phenyl- E8d, 357 (1-Oxid-Red.) 111-1,2,4-Triazol 5-Oxo-3-phenyl-4,5-dihydro- X/2, 159... 

Triazole (1 phenyl 3 hydroxy) triazophos Tributyl phosphine chlorphonium chloride... 

Phenyl-l,2,4-triazolo[l,5-c][l,3]benzoxazin-5-one 743, which exhibits benzodiazepine receptor affinity, has been prepared by cyclizing the 3-phenyl-5-(2-hydroxy-phenyl)- ,2,4-triazole 742 [535]. 

PM 60320 70321-86-7 Tinuvin 234 2-(2-Hydroxy-3,5-bis(l, 1 -dimethylbenzyl)-phenyl)benzo-triazole... 

Substituted (5R,6A,)-6-(dimethyl(phenyl)silyl)-2-phenyldihydropyrazolo[l,2- ][l,2,4]triazole-l,3(2//,5//)-dione 716, synthesized via the [3+2] annulation of a-substituted allylic silanes 715 with PTAD, were oxidized to the corresponding hydroxy substituted urazoles 717. This work shows that allylsilanes with a single substituent at the allylic carbon undergo exclusive stereoselective [3+2] annulation (Scheme 114) <2007TL6671>. 

Some interesting fused 1,2,3-triazole ring systems have been reported. A series of 5-piperidyl-substituted 7-hydroxy-3f/-l,2,3-triazolo[4,5-d]pyrimidines 143 has been synthesized from pipecolinate esters, benzylazides, and cyanoacetamide <06CHE246>. 4-Alkylidene-5,6-dihydro-4//-pyrrolo-[l,2-c][l,2,3]triazoles 144 were prepared from alkylidenecyclopropanes via diiodogenation/Cu(I)-catalyzed 1,3-dipolar cycloaddition/intra-molecular Heck reaction sequence <06SL1446>. 6,6-Dimethyl-2-phenyl-4,5,6,7-tetrahydro-27/-benzotriazol-4-one 145 were prepared from A-(5,5-dimethyl-3-oxocyclohexenyl)-S,S-diphenylsulfilimine and... 

Synthesis was directed towards metabolic stability and this was found in the bis-triazole series of compounds. Metabolic stability is achieved by the relative resistance of the triazole moiety to oxidative attack, the presence of halogen functions on the phenyl grouping, another site of possible oxidative attack, and steric hindrance of the hydroxy function, a site for possible conjugation. 

The vapor-phase pyrolysis of 4-hydroxy-1,2,3-triazole and its iV-methyl derivative affords methan-imine and its A-methyl analog. Analysis of the reaction path by the MNDO method shows the presence of two stable or metastable isomers, (liif)-4-hydroxy-l,2,3-triazole and its ketone protomer <89NJC551>. 4-Diazo-1,2,3-triazoles (122) thermolyze or photolyze in benzene to 4//-l,2,3-tri-azolylidenes (123) which convert benzene to 4-phenyl-1,2,3-triazoles and/or isomerize to a-diazo-nitriles (124). Intermediates (124) react with benzene via a carbene to give addition, ring expansion or substitution products (Scheme 17) <82TL5115>. The similar thermolysis of diazotriazoles in substituted benzene gives complex mixtures in which all of the components are sometimes impossible to isolate and identify <90AHC(48)65>. 

Meso-ionic 3-acyl-1-phenyl-1,2,3-triazol-4-ones (190, R = Ph or Me, = H) have been postulated as intermediates in the interesting base-catalyzed transformation of IV-acylsydnone imines (191, R = Ph or Me, R = H) into 4-hydroxy-1-phenyl-1,2,3-triazole (192, R = A similar photochemical transformation (191 190, R = Me or Ph, R = Ph) has also been reported. " A different base-catalyzed transformation of sydnone imine derivatives into pyrazolones has been recently reported. ... 

A number of general methods for the synthesis of meso-ionic 1,2,4-triazol-3-ones are available. Sodium ethoxide-catalyzed cyclization of 1-benzoyl-l,4-diphenylsemicarbazide (201, R = R = R = Ph, X = O) yielded anhydro-3-hydroxy-1,4,5-triphenyl-1,2,4-triazolium hydroxide (200, R = R = R = Ph). A general route to meso-ionic 1,2,4-triazol-3-ones (200) is exemplified by the formation of the 1,4,5-triphenyl derivative (200, R = R = R = Ph) from A-amino-MA -diphenylbenzamidine (202, R = R = R = Ph) and phosgene. In contrast with this ready meso-ionic compound formation, the corresponding reaction of the iV-methylbenzamidine (202, R = Me, R = R = Ph) did not yield the meso-ionic 1,2,4-triazol-3-one (200, R = Me, R = R = Ph). The product was in fact 3,4-diphenyl-2-methyl-l,2,4-triazol-5-onium chloride (203), which on heating gave 3,4-diphenyl-1,2,4-triazol-5-one (204, R = Ph). The formation of the A-methyl derivative (200, R = Me, R = R = Ph, yield 79%) by heating the 7V-thiobenzoyl semicarbazide (201, R = Me, R = R = Ph, X = S) with potassium carbonate in methyl cyanide has been reported. Another synthesis of A-methyl derivatives (200, R = Me) involves methylation of 3-methyl-4-phenyl-l,2,4-triazol-5-one (204,... 

Silyl-substituted diazoketones 29 cycloadd with aryl isocyanates to form 1,2,3-triazoles 194 (252) (Scheme 8.44). This reaction, which resembles the formation of 5-hydroxy-l,2,3-triazoles 190 in Scheme 8.43, has no analogy with other diazocarbonyl compounds. The beneficial effect of the silyl group in 29 can be seen from the fact that related diazomethyl-ketones do not react with phenyl isocyanate at 70 °C (252). Although the exact mechanistic details are unknown, one can speculate that the 2-siloxy-1-diazo-1-alkene isomer 30 [rather than 29 (see Section 8.1)] is involved in the cycloaddition step. With acyl isocyanates, diazoketones 29 cycloadd to give 5-acylamino-l,2,3-thiadiazoles 195 by addition across the C=S bond (252), in analogy with the behavior of diazomethyl-ketones and diazoacetates (5). 

Strongly activating substituents assist halogenation at the adjacent ring site. When 4-hydroxy-2-phenyl-1,2,3-triazole was treated with bromine, the product was mainly 5-bromo, but a small amount of 2-p-bromophenyl product was also observed. The corresponding 1-oxide gave only resins when similarly treated (88JOU599). 

Ichikawa et al. reported on the synthesis and antifungal activity of l-[(lfJ,2fi)-2-(2,4-difluorophenyl)-2-hydroxy-l-methyl-3-(l//-l,2,4-triazol-Tyl)propyl]-3-[4-(l//-l-tetrazolyl)phenyl]-2-imidazolidinone 597. Compound 597 was selected as an injectable candidate for clinical trials based on the results of evaluations of solubility, stability, hemolytic effect, and in vivo antifungal activities <2001CPB1102, 2001CPB1110>. 

Hydroxy-3-t-butyl-5-methyl phenyl)-5-chlorobenzo-triazole 316 1480 (1420-1560) PP... 

An early attempt in this direction was O. Dimroth s effort in correlating rate eonstants k with the solubihty S of the reactants in the solvents used [42]. While investigating the intramolecular rearrangement of 5-hydroxy-1-phenyl-1,2,3-triazole-4-earboxylie esters in various solvents, he found, in agreement with a rule formulated by van t Hoff [43], that the rate constants are inversely proportional to the solubihty of the rearranging isomers cf. Eq. (5-10). 

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