70264-71-0Relevant academic research and scientific papers
Thermal Stability Studies on a Homologous Series of Nitroarenes
Oxley, Jimmie C.,Smith, James L.,Ye, Hong,McKenney, Robert L.,Bolduc, Paul R.
, p. 9593 - 9602 (2007/10/02)
The thermal stabilities of a number of nitroarenes were examined in solution and in condensed phase.In general, increasing the number of nitro groups decreased thermal stability.Changing the substituent on 1-X-2,4,6-trinitrobenzene from X = H to NH2 to CH3 to OH accelerated decomposition; this effect was attributed to increased ease of intramolecular proton transfer to an ortho nitro group, thus weakening the carbon-nitrogen bond.In solution, the effect of increasing substitution from n = 1 to n = 3 on Xn(NO2)3C6H3-n was uniformly that of decreasing the thermal stability of the species.However, in condensed phase, results suggested that crystal habit may be more important than molecular structure; for X = Br, CH3, and NH2, the more substituted species was the more stable.
Methanol Attack on Highly Electrophilic 4,6-Dinitrobenzofurazan and 4,6-Dinitrobenzofuroxan Derivatives. A kinetic Study
Terrier, Francois,Chatrousse, Alain-Pierre,Soudais, Yannick,Hlaibi, Miloudi
, p. 4176 - 4181 (2007/10/02)
Methanol readily adds to the unsubstituted 7-carbons of 4,6-dinitrobenzofurazan (DNBZ) and 4,6-dinitrobenzofuroxan (DNBF) as well as the methoxy-bearing carbon of 7-methoxy-4,6-dinitrobenzofurazan (MDNBZ) to form the most stable methoxyl ? adducts known in this solvent.The formation and decomposition of the adducts are subject to general base and general acid catalysis, respectively, with β (α) values of ca.0.50, indicating a concerted mechanism.The results suggest that methoxide ion behaves as a base catalyst for methanol addition rather than as a nucleophile.The intrinsic rate constants k0 (in the Marcus sense) have been determined for the derivatives.Although the equilibrium constant for methanol addition to MDNBZ is somewhat greater than for addition to DNBZ and DNBF, the k0 value for the latter derivatives is about 10-fold higher than that for MDNBZ.This indicates a higher intrinsic barrier for attack at a methoxy-bearing than at an unsubstituted carbon, in qualitative agreement with previously reported patterns in the benzene series.The high reactivity of DNBZ, DNBF, and MDNBZ toward methanol and other bases, together with the very high stability of the resulting adducts, emphasizes the superelectrophilic character of these electron-deficient aromatics.
Synthesis of 4,6-Dinitrobenzofurazan, a New Electron-Deficient Aromatic
Read, Roger W.,Spear, Robert J.,Norris, William P.
, p. 1227 - 1237 (2007/10/02)
Preparation of 4,6-dinitrobenzofurazan (6) has been investigated by a number of routes.Its synthesis from 4,6-dinitrobenzofuroxan (4,6-dinitrobenzofurazan 1-oxide) (1) by reduction with triphenylphosphine proceeds in similar overall yield to the known method of nitration of 5-nitrobenzofurazan (8) but in fewer steps.Nitration of 4-nitrobenzofurazan (7) was studied as an alternative route, and the difference in reactivity between (7) and (8) is discussed.The benzofurazan (6) readily forms hydroxy and methoxy Meisenheimer complexes which have been isolated as stable, but highly explosive, potassium salts.
