New compound having PARP inhibiting activity

A compound represented by the following general formula (1) or a salt thereof; [Chemical Formula 1] ** ** Formula (wherein R1 represents a halogen atom, linear or branched alkyl having 1 to 8 carbon atoms, a hydroxy group, a group formed by replacing a hydrogen atom of a hydroxy group with a linear or branched alkyl having 1 to 8 carbon atoms, an amino group, a nitro group or a cyano group; R2 and R3 may be the same or different and each represents a hydrogen atom, an atom halogen or a linear or branched alkyl having 1 to 8 carbon atoms; R4 and R5 may be the same or different and each represents a hydrogen atom, a deuterium atom or a linear or branched alkyl having 1 to 8 carbon atoms or R4 and R5 may form an oxo group; Ra and Rb may be the same or different and each represents a hydrogen atom, a linear or branched alkyl having 1 to 8 carbon atoms optionally having a substituent or an aryl group optionally having a substituent; Ra and Rb can be joined together to form a heterocyclic nitrogen containing ring which may be substituted with one or more Rc; Rc represents a linear or branched alkyl group having 1 to 8 carbon atoms optionally having a substituent, a cycloalkyl group having 3 to 10 carbon atoms optionally having a substituent, an aryl group optionally having a substituent, a group heterocyclic optionally having a substituent, a hydroxy group, a group formed by replacing a hydrogen atom of a hydroxy group with a linear or branched alkyl group having 1 to 8 carbon atoms optionally having a substituent, a group formed by replacing a hydrogen atom of a formyl group with a linear or branched alkyl having 1 to 8 carbon atoms optionally having a substituent, a group formed by replacing a hydrogen atom of a formyl group with a cycloalkyl group having 3 to 10 carbon atoms optionally having a substituent, a group formed by replacing a hydrogen atom of a formyl group or a group formed by replacing one or both hydrogen atoms of an amino group with a linear or branched alkyl having 1 to 8 carbon atoms optionally having a substituent, a group formed by replacing a hydrogen atom of a group formyl with a group formed by replacing one or both hydrogen atoms of an amino group with a cycloalkyl group having 3 to 10 carbon atoms optionally having a substituent, a group formed by replacing a hydrogen atom of a formyl group with a group formed by replacing a hydrogen atom of a hydroxy group with a linear or branched alkyl having 1 to 8 carbon atoms optionally having a substituent, an amino group, a group formed by replacing one or both hydrogen atoms of a amino group with a linear or branched alkyl having 1 to 8 carbon atoms or a carboxyl group; ring A represents a benzene ring or an unsaturated heteromonocyclic ring; m represents 0, 1 or 2).