3,4 -Bi-l,2,4-triazole

Bis-l,2,4-triazole-3,5-diones such as 110 have also been used in Diels-Alder reactions, and give bispyridazines.171 The pyridazine derivative 111 is formed in quantitative yield from PTAD and 2,7-dimethyl-2,3,5,6-octatetraene,172 and the azadiene, 4-aza-l,3,5-triphenylpenta-2,4-diene, also reacts readily with PTAD to give 112.173 There are many other examples of Diels-Alder additions of ADC compounds to simple acyclic dienes which proceed entirely as expected the above selection has been limited to reactions of synthetic potential and with novel features. 

A potentially profitable discovery was that dibromide 74 will undergo an Ullman-type coupling to give the corresponding bis(l,2,4-triazole) 76 in 51% the reaction conditions employed were chosen in order that a trifluoromethyl substituent could be introduced but this reaction did not occur, the biaryl bond formation being preferred (Equation 27) <2006T3301 >. 

A/ -ally derivative + /V4-allyf (4.5%) derivative.r /V -prop-l-cnyl derivative. /V -propargyl derivative. Unstable N-azolylallene formed. bis-l,2,4,-triazol-I-yImethanc. Addition of alumina increases yield (81%)and totally inhibits isomerism.w Af -allyl (61%) + A -allyl (24%) derivatives. With K CO, (20 mmol) and RX (10 mmol) at 80°C for... 

Interest in polynitroarylenes has resumed over the past few decades as the demand for thermally stable explosives with a low sensitivity to impact has increased. This is mainly due to advances in military weapons technology but also for thermally demanding commercial applications i.e. oil well exploration, space programmes etc. Explosives like 1,3-diamino-2,4,6-trinitrobenzene (DATB) (13), l,3,5-triamino-2,4,6-trinitrobenzene (TATB) (14), 3,3 -diamino-2,2, 4,4, 6,6 -hexanitrobiphenyl (DIPAM) (15), 2,2, 4,4, 6,6 -hexanitrostilbene(HNS, VOD 7120 m/s, = 1.70 g/cm ) (16) and A,A -bis(l,2,4-triazol-3-yl)-4,4 -diamino-2,2, 3,3, 5,5, 6,6 -octanitroazobenzene (BTDAONAB) (17) fall into this class. TATB is the benchmark for thermal and impact insensitive explosives and finds wide use for military, space and nuclear applications. 

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). 

Agrawal and co-workers synthesized l,3-bis(l,2,4-triazol-3-amino)-2,4,6-trinitroben-zene (SDATO or BTATNB) (100) from the reaction of two equivalents of 3-amino-1,2,4-triazole (98) with styphnyl chloride (85). The performance of SDATO (calculated VOD 7609 m/s) is slightly higher than PATO while showing more insensitivity to impact. 

We have also reported a new explosive called, N,N -bis(l,2,4-triazol-3-yl)-4,4 -diamino-2,2, 3,3,5,5,6,6,-oclarnlroazobenzene (BTDAONAB) [Structure (2.39)], prepared on a laboratory scale and characterized for its thermal and explosive characteristics [25]. This explosive possesses a remarkable thermal stability which is better than the most thermally stable explosive, TATB and at the same time, its VOD is more than that of TATB. The chemical structures of some newly reported explosives are depicted in Figure 2.3. 

Wiley Hart(Ref 4) prepd 3,4 -Bis(l,2,4 triazole), large wh crysts(from hot w), mp 300-302°(dec) sol in dil alk obtd by slowly heating 3-amino-lH-l,2,4-triazole and diformyh hydrazine... 

The one-dimensional coordination polymer 158 with hexacoordinated tin atoms resulted from the reaction of diphenyltin dibromide with bis(l,2,4-triazol-l-yl)methane347. The bis(triazol-l-yl)methane coordinates to the tin atom in a bidentate bridging fashion through the nitrogen atoms at the 4-position of the triazole rings with intermolecular Sn—N distances of 2.454(7) A. 

Azido derivatives nitro-bis-l,2,4-triazoles a perspective hight energetic compounds have been prepared by functionalization or defunctionalization of (relative)... 

SERS data for glycine adsorbed on silver colloidal particles include a band at 238 cm-1 due to vAg-N.403 vAgN modes were assigned from the IR spectra of [bis(l,2,4-triazol-l-yl)methane]silver(I) complexes AgX tz2(CH2) ER3 MeCN, where X = N03, R = Ph, E = P, As, Sb, and related systems.404... 

There have been very few reports of simple 1,2,4-T preparation, however, a new method involving alkylation of bis(l,2,4-triazol-l-yl)methane (109) [prepared from 1,2,4-T and CH2Br2] allows exclusive preparation of 4-substituted 1,2,4-triazoles 110 <97T2253>. An improved preparation of 111 by reaction of thiocarbohydrazide with carboxylic acids at their melting temperature was reported <97JHC1255>. 

Poly(bis-l,2,4-triazole)s are a class of polymers in which two triazole rings are immediately adjacent. These polymers can be obtained by the reaction of oxalic acid bis-amidrazone with aromatic dicarboxylic acid dihalides or with fumaroyl chloride and subsequent cyclodehydration of the poly(acyl oxamidrazone)s. The process is shown in Figure 9.3. 

However, materials from poly(bis-l,2,4-triazole)s can be formed by dissolving poly(acyl oxamidrazone)s, e.g., poly(terephthaloyl oxamidraz-one) in dilute aqueous alkah. The solution is then spun or poured into a precipitation bath. The filaments or foils that are formed are washed and heated in an inert gas to a temperature of 240-320°C. 

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