Reactivity of bis(arylcarbamoyl)-N-arylphenacylamine oximes. Synthesis of 1,3-dihydroimidazol-2-ones and N-unsubstituted O-arylcarbamoylhydroxylamines

N-Arylphenacylamine oximes I reacted with aryl isocyanates in refluxing ben zene to give bis(arylcarbamoyl)-N-arylphenacylamine oximes 2 in good yields . Compounds 2 reacted with equimolar amount of TsOH.H2O in THF at room temp erature to give imidazol-2-ones 5 and O-arylcarbamoylhydroxylammonium tosyl ates 6 in high yields. Compounds 2 were heated under vacuum to induce Beckm ann fragmentation but the resulting products were 1,3,4-triaryl-1,3-dihydro imidazol-2-ones 5 instead of the expected 1,3-diazetidinones 4. (C) 1998 El sevier Science Ltd. All rights reserved.