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Anomalous 'Lossen-Type' Rearrangement. Synthesis of Functionalized Imidazolinones.-Treatment of the pyrroloimidazole derivative (I) with ammonia produces the ureidoimidazolecarboxamide (IIa) or the carboxylic acid (IIb) depending on the reaction conditions. The ester (IIc) is prepared in the presence of ethanol (III). The compounds (II) are further subjected to acid-or base-induced degradation, forming the imidazolones (IV). The transformation of (I) into (III) involves a Lossen rearrangement with trapping of the intermediate isocyanate by the vicinal amide moiety. -(CASTEEL, D. A.; GEPHART, R. S.; MORGAN, T.; Heterocycles 36 (1993) 3, 485-495; Div. Med. Nat. Prod. Chem., Coll. Pharm., Univ. Iowa,