From nitrotriazoles

Laval and Vignane reported the synthesis of the nitrotriazole (124) from the reaction of 3-nitro-1,2,4-triazole with 3,5-diamino-l-chloro-2,4,6-trinitrobenzene. The nitrotriazole (124) is a useful secondary high explosive, exhibiting high performance and a low sensitivity to impact. 

Triazole has values of 2.19 (as a base) and 10.26 (as an acid). A representative selection of acidity data Hammett treatment to the pXa values of triazoles. The Hammett equation is more satisfactory for acidic than basic values of triazoles <65ZC38l). For triazoles with only annular NH as acidic groups the Hammett a value is 6.00, while for 3-(or 5-) hydroxytriazoles it is 7.62. In both cases constants are most appropriate <65ZC304) this is also true for nitrotriazoles <70KGS558). 

Prepn A soln of 28.0g of l-morpholino-2-nitroethene, 35.Og of tosyl azide, and 400ml of abs ethanol is refluxed for 48 hrs. When this soln is chilled, 20—25g of tosyl morpholide crystallizes and is collected by filtration. Evapn of the solvent under reduced pressure leaves a tarry, oily residue. To this residue is added 100ml of chlf, and the resulting combination swirled until the cryst nitrotriazole is liberated from the oily residue. Washing the filtered tri-azole thoroughly with chlf furnishes 12.4g (60%) of white cryst product... 

The reaction of sodium azide with l-bromo-l-nitro-2-arylethenes takes place by a formal 1,3-cycloaddition Scheme leading to 4(5)-aryl-5(4)-nitro-l,2,3-triazoles [487-489], During the synthesis of nitrotriazoles the bromonitroarylethenes can be replaced successfully by the more readily obtainable l,2-dibromo-l-nitro-2-arylethanes [489], The intermediate product in the synthesis of 3-nitropyrazoles from 2,2-dinitroethanol and diazo ketones or diazoacetic ester is 1,1-dinitroethene [490,491] (Scheme 68). 

The results allowed a conclusion on the possibility of separate determination of metals and nitrotriazoles from the solution [987], The influence of nitrated 1,2,4-triazoles on corrosion and electrochemical behavior of low-carbon steels in aqueous solution of sodium sulfate has been investigated [988], The strong passivating action of nitrotriazoles on steel is caused by the formation of stable chemosorbed metal-azole films. 

Good yields of l-aryl-4-nitrotriazoles (288, 289) are obtained on cycloaddition of 1-morpholino-2-nitroethylene (287) (review 8ITI453) with aryl azides (66tl6043, 68G949). The Spiro cycloaddition product from (290) and phenyl azide isomerizes to the triazole (291)... 

Alternative syntheses for 4-aminotriazoles without substituents on nuclear nitrogen atoms are described in Section IV,A. namely, the action of ethyl azidoformate or tosyl azide on activated cyanomethylene compounds, or tosyl azide on malonamideamidine however, the generality of these reactions is yet to be demonstrated. Another approach is available through the reduction of 4-nitrotriazoles, obtained from l-morpholino-2-nitroethylene (Section IV,F). 

---