1.2.3- Triazoles nitration

Among the nitrated and/or nitrited derivatives only 3-amino-a-as(or 1H-1,2,4)-triazole nitrate and 3-0 i tram ino-a-as (or lH-l l-triazole were found in the literature... 

Amino a sym triazole Nitrate or 3-Amino lH-l,2,4-trIazole Nitrate, HC-NH-N + HNOs,... 

In azole chemistry the total effect of the several heteroatoms in one ring approximates the superposition of their separate effects. It is found that pyrazole, imidazole and isoxazole undergo nitration and sulfonation about as readily as nitrobenzene thiazole and isothiazole react less readily ica. equal to m-dinitrobenzene), and oxadiazoles, thiadiazoles, triazoles, etc. with great difficulty. In each case, halogenation is easier than the corresponding nitration or sulfonation. Strong electron-donor substituents help the reaction. 

Amino-l,2,4-triazole has been prepared by evaporating formylguanidine nitrate with sodium carbonate, and from 5(3)-amino-1,2,4-triazole carboxjdic acid-3(S) by heating above its melting point, or by a long digestion with acetic acid. ... 

The most common corrosion inhibitors, which may form protective films on the metal surfaces, are borates, molybdates, nitrates, nitrites, phosphates, silicates, amines, triazoles, and thiazioles (e.g., monoethanolamine, urotropin, thiodiglycol, and mercaptobenzothiazole). The addition of such inhibitors does not effectively protect against corrosion [137]. Some corrosion inhibitors are shown in Figure 14-3. 

The precursory l,2,4-triazole-3-diazonium nitrate is extremely unstable, even in ice-cold aqueous solution, and no attempt was made to isolate the title diazo... 

See Other ENDOTHERMIC COMPOUNDS, HIGH-NITROGEN COMPOUNDS, TRIAZOLES 2270. l,2,4-Triazolo[4,3-a]pyridine silver nitrate... 

Treatment of benzimidazole with ozone and N02 results in a complex mixture of mono- and di-nitrated benzimidazoles and triazoles. However, nitration of 5-nitrobenzimidazole 1209 under such conditions leads to two major products, benzotriazoles 1210 and 1211. The mechanism of ring conversion from benzimidazole to benzotriazole is not clear (Equation 29) <2004CPB570>. 

Table 11 Reaction of ethyl nitrate with 4-amino-1,2,4-triazole derivatives (Equation 31)...

The main starting compound is the labeled nitroguanidine 257 obtained from guanidine with isotope-labeled potassium nitrate. Reduction of 257 to hydrazine carboximidamide 258 was carried out with zinc and, then, ring closure to 3-amino[l,2,4]triazole 259 was carried out using formic acid. Finally, the ring closure to form the [l,2,4]triazine ring - similar to other procedures presented in Scheme 54 - was perfected by reaction with nitrous acid followed by treatment with ethyl nitroacetate to 260. 

Amino-3-phenyl-1,2,4-triazole, Nitrous acid, 2952 Benzenediazonium chloride, 2230 Benzenediazonium iodide, 2250 Benzenediazonium nitrate, 2275... 

Triazido-1,3,5 -triazine, 1348 l,2,4-Triazole-3-diazonium nitrate, 0680 1,3,5 -Triphenyl-1,4-pentaazadiene, 3754... 

Bis(l-methylbenzotriazole)cobalt(II) nitrate, 3652 A-Chloro-4,5 -dimethy ltriazole, 1490 5-Cyano-4-diazo-4//-l,2,3-triazole, 1345... 

Triazole-3-diazonium nitrate, 0680 See other high-nitrogen compounds... 

Agrawal and co-workers have reported the synthesis of A,A -bis(l,2,4-triazol-3-yl)-4,4 -diamino-2,2, 3,3, 5,5, 6,6 -octanitroazobenzene (17) (BTDAONAB) via nitration-oxidative coupling of 4-chloro-3,5-dinitroaniline (152) followed by nucleophilic displacement of the chloro groups with 3-amino-1,2,4-triazole. BTDAONAB has the unique distinction of being the most thermally stable explosive reported so far (DTA exotherm 550 °C) as compared to well known thermally stable explosives such as TATB ( 360 °C), TACOT ( 410 °C), NONA ( 440 50 °C), and PYX ( 460 °C). 

The nitrogen atoms of heterocycles like imidazoles and triazoles have been converted into IV-nitroimide groups. The A -nitroimide (164) is synthesized from 1-amino-1,3,4-triazole (162) by IV-amination of the tertiary nitrogen with 0-picrylhydroxylamine, addition of nitric acid to give the nitrate salt (163), followed by IV-nitration with nitronium tetrafluoroborate in acetonitrile. The 1,2,3-triazole (165) and the imidazole (166) ° are synthesized in a similar way. The synthesis of IV-nitroimides has been the subject of an excellent review. ... 

C-Nitration of 1,2,3-triazole and 1,2,4-triazole rings can be achieved with either mixed acid or solutions of nitric acid in acetic anhydride. V-Nitration is usually achieved with nitric acid in acetic anhydride at ambient to subambient temperatures. Thermal rearrangement of the N-nitro product to the more stable C-nitro product often occurs at higher nitration temperature. 

This is seen during the nitration of PATO (99), which on treatment with a mixture of nitric acid in acetic anhydride at 40 °C for 30 minutes yields the A-nitro product (106), whereas the same reaction at 60 °C for 1.5 hours yields the C-nitro product (107). An explosive known as PANT (109) has been prepared from the reaction of 4-amino-1,2,3-triazole (108) with picryl chloride followed by C-nitration of the 1,2,3-triazole ring with mixed acid at room temperature. ... 

Treatment of the ammonium salt of 3,5-dinitro-1,2,4-triazole (113) with hydrazine hydrate leads to selective reduction of one of the nitro groups to yield 3-amino-5-nitro-1,2,4-triazole (ANTA) (114), a high performance explosive (calculated VOD 8460 m/s) possessing thermal stability (m.p. 238 °C) and an extremely low sensitivity to impact. ANTA (114) is also synthesized from the nitration of 3-acetyl-l,2,4-triazole with anhydrous nitric acid in acetic anhydride at subambient temperature followed by hydrolysis of the acetyl functionality. The ammonium salt of 3,5-dinitro-l,2,4-triazole (113) is itself a useful explosive which forms a eutectic with ammonium nitrate. ... 

Nitro-l,2,4-triazol-5-one (NTO) (140) is prepared from the nitration of l,2,4-triazol-5-one (139) under a variety of conditions the latter prepared from the condensation of semicarbazide... 

B. Chen, J. Li and Y. On, Modified Preparation and Nitration of 3-Picrylamino-l,2,4-triazole , in Proc. 17th International Pyrotechnics Seminar (Combined with 2nd Beijing International Symposium on Pyrotechnics and Explosives), Beijing Institute Technical Press, Beijing, China, 196 (1991). 

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