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Synthesis of Substituted N-Hydroxyureas via the in situ Generation of t-ButoxyIsocyanate. -The attempt to prepare hydrazine products starting from carbamate (I) and amines yields N-substituted ureas instead. A two-step sequence is elaborated which allows the preparation of N-hydroxy ureas via base-induced Lossen-type rearrangement of (I) followed by reaction of the intermediate tert-butoxy isocyanates with amines and subsequent N-deprotection. In the case of substrates (V) and (VIII), the same final product (VII) is formed where in the latter case the aromatization takes place during deprotection. -(KRAUSE, J. G.; LESKIW, B. D.; EMERY, M. L.; MCGAHAN, M. E.; MCCOURT, M. P.; PRIEFER*, R.; Tetrahedron Lett. 51 (2010) 27, 3568-3570,