273-09-6Relevant articles and documents
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.
Vergleichende Untersuchungen zur Arylaminierung von Benzofuroxan-Derivaten
Goehrmann, B.,Niclas, H.-J.
, p. 1054 - 1060 (2007/10/02)
The amination of benzofuroxan 2a and monosubstituted benzofuroxans 2b-e with alkali metal salts of formanilides 1 and sodium acetanilides 6 is described.Thus, the reaction of 2a with 6a-d gives the benzotriazole 1-oxides 3a-d.The benzofuroxans 2b and 2c react with sodium formanilides to give the isomeric mixtures 3f/3g and 3h/3i.Potassium 4-nitroformanilide reduces 2a furnishing benzofurazan 7.Nitrosubstituted benzofuroxans such as 2d and 2e undergo a carbocyclic amination leading to the benzofurazans 8 and 9.
An Improved and Efficient Synthesis of Quinoxalinecarboxamide 1,4-Dioxides from Benzofuroxan and Acetoacetamides in the Presence of Calcium Salts
Stumm, G.,Niclas, H.-J.
, p. 736 - 744 (2007/10/02)
An improved and efficient method for the preparation of the title compounds 3 is described.Thus, quinoxalinecarboxamide 1,4-dioxides 3 are synthesized in high yields by reaction of benzofuroxan 1 with acetoacetamides 2 in the presence of catalytic amounts of calcium salts and ethanolamine.The reaction is assumed to involve a chelate mechanism with 4 as intermediate.Side reactions are studied by means of HPLC and TLC.
REACTIONS OF FUROXANS WITH PHOSPHORUS YLIDES
Argyropoulos, N. G.,Gallos, J. K.,Nicolaides, D. N.
, p. 3631 - 3636 (2007/10/02)
Benzofuroxan (1) reacts with phosphorus ylide 2 to give benzimidazole derivatives 8 and 10, whereas reaction of 1 with ylide 12 furnishes quinoxaline 17 via an initial Wittig-type reaction.Similarly the reaction between the furoxanoquinoxalines 19a or 19b and the ylide 2 yielded compounds 22a and 22b, respectively.In these reactions as well as in the reactions of the above furoxans with other phosphorus ylides, a significant deoxygenation of the furoxans to furazans with subsequent oxidation of the ylides is generally observed.
