1,3,4-Oxa(thia)diazino [i,j]-annelated quinolines: a new type of key intermediate in the synthesis of tricyclic fluoroquinolones

The synthesis of new derivatives of 1,3,4-oxa(thia)diazino[6,5,4-i,j]quinolines, which have a structure that is very similar to the ofloxacin skeleton, by intramolecular cyclizations of ethyl 3-(R-carbonylhydrazino)- and 3-(R-thiocarbonylhydrazino)-substituted 2-polyfluorobenzoyl acrylates, is described.