The synthesis of novel substituted pyrroloquinolinones is described by concomitant ring contraction cyclization form 2-(2-amino-5-nitro-phenyl)-[4H]-1, 3-thiazines, which were derived from N-substituted 5-nitro-anthranilonitrile. An easy access to novel 4-thiono-1, 4- dihydro-1, 3-quinazoline heterocycles is also mentioned.
