2- aminobenzotriazoles

Table 2 Theoretical and experimental geometries of the amino groups of 2-aminobenzotriazole.

The corrected structural parameters of benzotriazole obtained from microwave spectroscopy are shown in Figure 6 <93JSP(161)136>. For comparison, the molecular dimensions measured by x-ray of crystalline benzotriazole-1-carboxamide <93ACS167> and 2-aminobenzotriazole, as an example of a 2-substituted benzotriazole, are listed in Figure 6 <90JCS(P2)237>. 

The N chemical shifts and /( N— H) coupling constants of 1 -amino- and 2-aminobenzotriazole in DMSO solution have been reported and the N assignments are shown in Figure 9. There is a correlation between the chemical shifts of A -aminoazoles and A -methylazoles <90JCS(P2)237>. 

Hydroxybenzotriazole is nitrated with nitric acid in glacial acetic acid to give 6-nitro derivative, whereas the use of sulfuric-nitric mixture does not lead to positive results [274], 1- and 2-Aminobenzotriazoles react with nitronium boron fluoride to form nitroimides isolated as alkali metal salts, involving no nitro group in the phenylene fragment [109],... 

Lead tetraacetate oxidizes 2-aminobenzotriazole (4) to cis,cis-muconitrile (7) in 64% yield, presumably through the nitrenes (5) and (6). The same product is obtained in 50% yield by lead tetraacetate oxidation of o-phenylenediamine (8). ... 

Only a single patent reports arylation of A-aminoazoles. 2-(t>-Nitrophe-nyUaminobenzotriazole was obtained on heating 2-aminobenzotriazole with o-nitrofluorobenzene in DMF in the presence of anhydrous soda (65USP3184471). An attempt to carry out such a reaction for I-amino-benzotriazole failed, probably because of the poor NH-acidity of this compound. 

The lead tetraacetate oxidation of 1-aminobenzotriazole leads to benzyne (Eq. 107), whereas 2-aminobenzotriazole ring opens to Z,Z-mucononitrile (Eq. 108).398... 

Oxidation of heterocyclic amino derivatives yields various reaction products depending on the structure of the amine. 4-Benzylamino-3-methyl-4//-1,2,4-triazole is oxidized with DCT in chloroform to give the azomethine derivative 110 (69ZC325). l-Amino-4,5-diphenyl-l,2,3-triazole under the action of CBT forms diphenylacetylene 2-aminobenzotriazole yields cis, cw-l,4-dicyanobuta-l,3-diene and 1-aminobenzotriazole yields a mixture of chlorobenzene and o-dichlorobenzene. Oxidation of 1-aminobenzotriazole in the presence of tetraphenylcyclopentadienone leads to 1,2,3,4-tetraphenylnaphthalene via benzyne intermediate [68JCS(CC)1305 69JCS(C)1474] (Scheme 101). 

The practice of using an insoluble polymer to isolate and kinetic-ally stabilize a reactive intermediate has been addressed in several reports, most commonly using DVB cross-linked polystyrene as a support. In these cases, the three dimensional structure of the polymer and rigidity of the polymer backbone diminish intramolecular reactivity between two sites on the same polymer bead. Physical constraints preclude any significant reaction between two different polymer beads. Similar, less dramatic reduced intramolecular reactivity has also been noted for reactive intermediates bound to linear polystyrene. For example, o-benzyne bound to linear polystyrene has been shown by Mazur to have enhanced stability relative to non-polymer-bound -benzyne (35). In this case, o-benzyne was generated by lead tetraacetate oxidation of a 2-aminobenzotriazole precursor, 1. Analysis of the reaction products after cleaving the benzyne derived products from the polymer by hydrolysis showed a 60% yield of aryl acetates was obtained (Equation 11). In contrast, the monomeric aryne forms only coupled products under similar conditions. Further comparisons of the reactivity of -benzyne bound to insoluble 2% or 20%... 

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