Aminotriazoles, structure

The mass spectra of a number of A-substituted isomeric derivatives based on the 3-thiomethyl-5-aminotriazole structure have been correlated with the type of cleavage of the substituent <83JCR(S)126>. 

An interesting example of how the reaction conditions can influence the structure of the product is shown in Scheme 2-10. Depending on the acidity of the reaction medium and on the reaction time, the diazotization of aminotriazoles (2.18) yields the nitrosoamines (2.19), the chloro compounds (2.20), or the azo coupling products i.e., the triazenes (2.21), as shown by Gehlen and Dost (1963). 

Treatment of bis(tolylimidoyl) dichloride 358 with 3-aminotriazole (that can exist as two tautomeric structures) affords, after refluxing in THF in the presence of triethylamine, a separable mixture of 5,6-bis-(4-tolylimino)-5//-... 

Structural information on aromatic donor molecule binding was obtained initially by using H NMR relaxation measurements to give distances from the heme iron atom to protons of the bound molecule. For example, indole-3-propionic acid, a structural homologue of the plant hormone indole-3-acetic acid, was found to bind approximately 9-10 A from the heme iron atom and at a particular angle to the heme plane (234). The disadvantage of this method is that the orientation with respect to the polypeptide chain cannot be defined. Other donor molecules examined include 4-methylphenol (p-cresol) (235), 3-hydroxyphenol (resorcinol), 2-methoxy-4-methylphenol and benzhydroxamic acid (236), methyl 2-pyridyl sulfide and methylp-tolyl sulfide (237), and L-tyrosine and D-tyrosine (238). Distance constraints of between 8.4 and 12.0 A have been reported (235-238). Aromatic donor proton to heme iron distances of 6 A reported earlier for aminotriazole and 3-hydroxyphenol (resorcinol) are too short because of an inappropriate estimate of the molecular correlation time (239), a parameter required for the calculations. Distance information for a series of aromatic phenols and amines bound to Mn(III)-substituted HRP C has been published (240). 

Bis acylhydrazones or bis aroylhydrazones of a-diketones also give derivatives of 1-aminotriazoles on mild oxidation (Scheme 21).i n The product was originally assigned a dihydrotetrazine structure, and other possibilities were considered,but Curtin and Alexandrou proposed the isoimide structure (8) which was, for the product obtained from biacetyl bis(benzoylhydrazone), confirmed by X-ray crystallography. The mechanism given in Scheme 21 has been put forward for its formation ... 

There are striking similarities in the physical [Fig. 2 (126) and Fig. 3 (126b)] and chemical properties of the cyanylated enzyme (Table V) and the aminotriazole-catalase derivative. Both retain the structural integrity and ferric oxidation state of the native enzyme. In addition, as gauged by their optical spectra [Fig. 2, but see also Figs. 6A and 6B of Margoliash and Novogrodsky (111)], the modification of the apopro-... 

The dipole of 4-azidotriazole, a compound related to 4-aminotriazole, was found to be 2.35 D (in dioxane, 25°C) and was compared to 4.46 D for the parent 1,2,3-triazole. It was concluded, after comparative studies with other azido compounds, that the predominating tautomer was HN-2 (11). Whether the azido group is oriented mainly Z or was not experimentally determined, but CNDO calculations indicated the Z form, i.e., the one with the azido group turned toward the nearest ring-nitrogen atom (N-3) (78BSB189). For the use of H NMR to assign cis and trans structures, see Section II,D. 

All other papers are concerned with the more accessible 1-aminotriazoles. Pechmann (1900CB644) and Wolff (02LA125 03CB3617) first independently synthesized these compounds. However, in contrast to Wolff, Pechmann made a mistake in the correct choice of a structure of the... 

In its most primitive form, the structure of the parent molecule is inconsequential. Thus if the value of the substituent group is known, it can be used in any molecule regardless of its structure. Linear relationships based on such similarity of effects are referred to as extrathermodynamic relationships, because the approach does not call for information on the microscopic nature of the structures. To that extent it retains the fundamental character of the thermodynamic approach. A typical linear relationship with respect to the substituent effect in the rearrangement of aminotriazoles, i.e.,... 

J. M. Strum and M. J. Karnovsky, Aminotriazole goiter Fine structure and localization of thyroid peroxidase activity, Lab. Invest. 24, 1-12 (1971). 

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