Triazoles aminotriazoles

SYNS AMEROL AMINOTRIAZOLE 2-AMINOTRIAZOLE 2-AMINO-l,3,4-TRIAZOLE 3-AMINOTRIAZOLE 3-AMINO-s-TRIAZOLE 3-AMINO-1,2,4-TRIAZOLE (ACGIH) 3-AMINO-l,2,4-TRLAZOLE 3-AMINO-lH-l,2,4-TRIAZOLE AMINOTRIAZOLE (PLANT REGULATOR) AMINO TRIAZOLE WEEDKILLER 90 AMINOTRIAZOL-SPRITZPULVER AMITOL AMTRIL AMITRILT.L. 

The 4- and 5-amino-l,2,3-triazoles are diazotizable, e.g. the diazonium salt from 4-aminotriazole-5-carboxamide with potassium iodide gives the 4-iodo derivative, and that from 4-amino-l,5-diphenyltriazole gives 1,5-diphenyltriazole in ethanol (74AHC(16)33). 

Thiadiazinotriazolopyrimidines can be prepared in several ways from the hydrazine-substituted thiadiazino-pyrimidine 186. Reaction with carbon disulfide gives the thione 187 reaction with either anhydrides or orthoformates with sulfuric acid gives the substituted triazoles 188, and reaction with cyanogen iodide gives the aminotriazole 189 (Scheme 47) <2004HC0335>. 

A special approach to [l,2,4]triazolo[3,2-c][l,2,4]triazine derivatives is the transformation of 3-diazo[l,2,4]triazoles, easily available by diazotation of aminotriazoles. These compounds already contain the five nitrogen atoms in the correct sequence in order to form the desired bicyclic ring system and, thus, their reaction with proper bifunctional reagents can give rise the cyclized products in one single step. Such transformations are collected in Scheme 50. 

Studies have been made of the fate of 3-amino 1,2,4 triazole herbicide in soils [106], while adsorption of aminotriazole by clay minerals has been postulated, little is known of the interaction with pure clay minerals, particularly of the montmorillonite group. The importance of such reactions cannot be overemphasized in view of their bearing on the persistence of the herbicide in the soil. 

Aminotriazoles and their derivatives can be prepared from bis hydrazones and from substituted bis hydrazones of a-diketones. The bis hydrazones may in some cases be prepared more conveniently from -bromoketones than from a-diketones. Oxidation with mercuric oxide or with manganese dioxide gives the 1-aminotriazoles directly (Scheme m-ns Although two isomeric triazoles would be ex-... 

Diphenyl- -triazole is aminated by reaction with hydroxylamine-0-sulfonic acid. The I - and 2-aminotriazoles are formed in approximately equal amounts. Intramolecular amination of 1- and 2-aryltriazoles is achieved by generating a nitrene intermediate in the ortho position of the aryl substituent for example, in the thermolysis (Scheme 42) of the azide (17). ... 

Carboxylation of C-lithio or Grignard derivatives of triazoles gives the corresponding carboxylic acids. 4-Aminotriazole has been car-boxylated at the 5-position (14%) by heating with aqueous sodium bicarbonate. ... 

Displacement of nitrogen from diazonium salts derived from 4- or 5-aminotriazoles can be achieved in the same manner as for other aromatic diazonium salts for example, diazotization of 4-amino-triazole-5-carboxamide and reaction with iodine and potassium iodide gives the 4-iodo derivative. ... 

Reaction of 4-aminotriazole-5-carboxamide and 4-amino-5-phenyl-triazole with acetylacetone and piperidine gives a different type of fused triazole, the t>-triazolo[3,4-a]p5Timidine system (Scheme 48). 

Among binucleophiles used in this reaction 3-amino-l,2,4-triazole and 2-aminothiazole were also selected. However, in the reaction of the latter with phenyl isonitrile and formaldehyde, only the moderate yields of the target product 101 were observed by the LC-MS analysis of the crude reaction mixture. In case of aminotriazole, any product of the reaction was failed to be detected (Scheme 47). 

Synonym Aminotriazole Amitrole-T Amizol Azolan 3-amino-l,2,4-triazole AFA Cytrol Whedazol... 

For a review of V-amino-l,2,3-triazoles, see Kuzmenko and Pozharskii <92AHC(53)85>. For the oxidation of iV-aminotriazoles and benzotriazoles, also see Section 4.01.4.11. 

Amino-1,2,3-triazoles with a substituent at the 4-position have been prepared (i) from azides and active methylene nitriles (ii) from azides and ynamines (iii) from diazomethane and carbo-diimides (iv) from azides and 1,1-diaminoethenes and (v) from the rearrangement of 3-hydrazono-1,2,4-oxadiazoles. Among these, the first method, a regiospecific process, is the most versatile and convenient although it is suitable only for 5-NH2-substituted triazoles. Other methods are used to prepare 5-NHR , 5-NR R - and 5-NHCOR-substituted triazoles. Intramolecular cyclization of suitable precursors also gives 5-aminotriazoles. For example, a-imino-a-piperidyl phenylhydrazones (838), in the presence of copper acetate, give 5-piperidyl-triazoles (839) (Equation (85)) <94H(38)739>. 

Aminotriazoles which are appropriately substituted at the C(5)-position are important intermediates for the synthesis of 8-azapurines. These reactions have been reviewed <86AHC(39)ll7>. The pharmaceutically useful acyclonucleosides bearing 1,2,3-triazolines and 8-azapurines have been synthesized <888879). 4,5-Diaminotriazoles react with 1,2-dicarbonyl reagents to give 1,2,3-triazolo[4,5- )]pyrazines. 4,5-Diamino-2-phenyltriazole and sulfur monochloride afford the triazolo[4,5-c][l,2,5]thiadiazole (855) <86AHC(40)129>. The synthesis of triazolopyridines from triazoles has been described in a review <83AHC(34)79>. For further applications of substituted triazoles in preparations of complex heterocycles, see Section 4.01.4. 

Triazole melts at 120-121 °C and boils at 260 °C. It has a density of 1.132 and a specific conductivity of about 10 0 cm , of the same order as imidazole. Triazole dissolves readily in water and ethanol but is only slightly soluble in ether. Substitution on N(l) usually lowers the melting point this effect is usually much smaller for substitution at N(4), although 4-aminotriazole has a melting point of 84-86°C. 3-Aminotriazole has a melting point of 159°C and the 3-thiol derivative of 221-... 

The method of choice for the synthesis of triazoles depends largely on the substitution pattern required. Acyclic compounds are usually the preferred substrates and the hydrazines are readily available and cheap. For 3-aminotriazoles, dimethyl A-cyanoisothiourea or diphenyl cyano-carbonimidates, although more expensive, are valuable precursors since the 5-substituent can be varied widely. 1,3-Dipolar addition using nitrilimines has been extensively used and again can be... 

Amino-l,2,4-triazole was alkylated with 4-nitrobenzyl bromide by simply refluxing the mixture in isopropanol to give SO in excellent yield. The aminotriazole SO was deaminated with NaNOa in aqueous HCI and the nitro group was reduced with ammonium formate catalyzed by 10% Pd/C to deliver 47 in an improved yield over the route shown in Scheme 17. Diazotization of 47, reduction of the diazonium salt with sodium sulphite and Fischer indolization of the resulting hydrazine with 4-( /, /-dimethylamino)butanol dimethyl acetal was performed in a single step to afford rizatriptan (4) in 45% yield. 

Addnl Refs on Aminotriazoles and Their Derivatives a)J.Reilly P.J+Drumm,JCS 1926,1729-37[Prepn and props of aminopropyi -1,2,4-triazoles and their salts and derivs. One of the derivs described in this tsaner is... 

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