PREPARATION OF -(2-ARYL-2-OXO-ETHYLIDENE)-5,7-DINITROBENZOFURAZAN DERIVATIVES

Upon treatment with KF in acetonitrile the zwitter-ionic Meisenheimer complexes 3 undergo beta-elimination leading to potassium ethylidene)- 4,6-dinitro-7,x-dihydrobenzofurazanide 1-oxides 4 in 72-87 % yield. Co mpounds 4 give 7-(2-aryl-2-oxo-ethyl)-4,6-dinitrobenzofuroxans 6 when treated with hydrochloric acid. thylidene)-5,7-dinitro-4,x-dihydrobenz ofurazanides 5 are obtained by reaction of 3 with sodium methoxide. Th e structure of 5e is confirmed by X-ray structure analysis. The reacti on of complexes 8 with acetic acid/potassium acetate at 80-degrees-C a ffords thylidene)-5,7-dinitro-4,x-dihydrobenzofurazanides 9 in moderat e yields.