AZIRIDINES .21. 1,4-DIAZABICYCLO[4.1.0]HEPT-4-ENES AND 1,1A-DIHYDRO-1,2-DIARYLAZIRINO[1,2-ALPHA]QUINOXALINES

The syntheses and reactions of the 1,4-diaza[4.1.0] hept-4-enes (2) and the 1,1a-dihydro-1,2-diarylazirino-[1,2-a]quinoxalines (3) are described. These compounds are prepared by the reaction of 1-phenyl-2,3-dibromo-3-aryl-1-propanones with ethylenediamine and o-phenylenediamine, respectively. Compounds 3 undergo carbon-carbon bond fission of the aziridine ring in refluxing toluene and form adducts with diethyl azodicarboxylate, dimethylacetylene dicarboxylate, dibenzoylacetylene, aromatic aldehydes and acenaphthylene. Compounds such as 3 also react with nitrosobenzene to form nitrones and 2-phenylquinoxaline and pyrolyze to stilbenes and 2-phenylquinoxaline. Compounds 3 isomerize in the presence of acid to 2-benzyl-3-arylquinoxalines. Compounds 2 are converted in concentrated sulfuric acid into benzyl phenyl diketones. © 1969, American Chemical Society. All rights reserved.