Reactions of N-aryl-N-(4,5-dihydro-1H-imidazol-2-yl) hydroxylamines with methanesulfonyl chloride. Synthesis and acylation of 2,3-dihydro-1H-imidazo [1,2-a]benzimidazoles

Reactions of N-aryl-N-(4,5-dihydro-1H-imidazo-2-yl)-hydroxylamines 1a-d wit h methanesulfonyl chloride in the presence of triethylamine afforded 2,3-di hydroimidazo[1, 2-a]benzimidazoles 2a-d. The latter compounds treated with acetic anhydride, methane or phenylsulfonyl chlorides gave N-1 acetyl or N- 1 methane or phenylsulfonyl derivatives 3a-d and 4a-b, respectively.