XXIX XXVII of I1 by the reaction of ethyl N-(5-nitro-% thiazolyl)-glycinate (XXVIII) with isocyanates. We found, however, that upon treating XXVIII in DMF with alkyl isocyanates, the expected intermediate XXIX was not isolated, but facile cyclization led directly to the substituted hydantoins XXVII (R= CH3, CzHb, CH2CHzC1). We have confirmed the high activity of these materials in mice against S. mansoni infections. TO prepare the required ...
