Disclosed are naphthalimide derivatives and in particular e.g. N – aryl – substituted naphthalimidopropylamine deriva tives ( i.e. 2- [ 3- ( amino ) propyl ) -1H – benz [ de ] isoquinoline – 1,3 ( 2H ) -dione derivatives ) such as e.g. such as e.g. ( Formula I ) or ( Formula III ) as anti – parasitic agents for the treatment of Leishmaniasis . The compounds could also be useful to treat viral , bacterial and / or neoplastic diseases . The description discloses exemplary synthesis as well as biological tests against Leishmania infantum parasites ( e.g. pages 54 to 58 ; examples 1 to 7 ) . Exemplary compounds are : ( example 3 ) ( example 4 ) 2- ( 3 – ( ( 5 – amino naphthalene – 1 – yl ) amino ) pro pyl ) -1H – benzo [ de ] isoquinoline – 1 , 3 ( 2H ) -dione ( example 5 ) 2- ( 3 – ( ( 5 – amino naphthalene – 1 – yl ) amino ) propyl ) -1H – benzo [ de ] isoquinoline – 1,3 ( 2H ) -dione ( example 6 ) .