Synthesis of novel 4-amino-5-(disubstituted amino)-2-phenyl-2H-pyridazin-3-ones

Substituted 4-amino-2-phenyl-1-2H-pyridazin-3-one 5a-5j have been prepared from 4-amino-5-chloro-2-phenyl-2H-pyridazin-3-one 1 which on reactions with acetyl chloride or acetic anhydride gives 4-acetylamino derivative 2 or 4-diacetylamino derivative 3, respectively, Derivatives 2 and 3 with dialkylamines and cyclic amines yielded appropriate 4-acetylamino-5-(disubstituted amino)-2-phenyl-2H-pyridazin-3-ones 4a-4j. Subsequent alkaline hydrolysis of the acetylamino derivatives 4a-4j let to the title compounds 5a-5j, which were screened fur pesticidal activity; but none of them reached activity of the used standards.