Trifluoromethanesulfonylimides of Arenehydroxamic Acids and Their Aza Lossen Rearrangement.

Abstract Trifluoromethanesulfonylimides of arenehydroxamic acids ArC( NSO 2 CF 3 )NHOH ( 1 ), analogues of arenehydroxamic acids, in which sp 2 hybridized oxygen atom is replaced by the much stronger electron-withdrawing group NSO 2 CF 3 , have been synthesized, and the abilities of these compounds to undergo transformations similar to the Lossen rearrangement have been studied. At heating O -trimethylsilyl or O -tosyl derivatives of acids 1 rearrange to carbodiimides ArN C NSO 2 CF 3 or products of their hydration, the corresponding carbamides. Interaction of acids 1 with sulfinyl chloride or phosphorus pentachloride results in formation of N -trifluoromethylsulfonyl- N ′-arenechloroformamidines, ArNHC(Cl) NSO 2 CF 3 , which were transformed into their morpholine derivatives and thus characterized.