New bioactive benzopyridazine derivatives 5a-d and 7a,b were successfully synthesized as antiproliferative agents via nucleophilic substitution reaction of 1-chloro-4-phenyl benzopyridazine 1 with the aromatic diamines 2a,b respectively to form the free amines 3a,b, The free amines 3a,b coupled with phenyl isocyanates 4a, phenyl isothiocyanate 4b or 2-naphthalene sulfonyl chloride 6 to form 5a-d a...