Pyridazinone derivatives, preparation thereof and insecticidal, acaricidal, fungicidal compositions

Abstract From the Canadian patent

Novel 3(2H)-pyridazinone derivatives having the formula I: (I), wherein, R is a straight or branched C2 to C6 alkyl R1 and R2, are each independently hydrogen or a lower alkyl R4 is a, halogen, R3 is a halogen, an alkyl a cycloalkyl, an alkoxy, a, haloalkyl, a haloalkoxy -CN, -NO2, a phenyl, a benzyloxy, a, benzyl a phenoxy, a phenylthio, a pyridyloxy, a quinoxalyloxy a, lower alkenyloxy, a lower alkylthio a lower haloalkylthio, -Si(CH3)3, -OH, -N(CH3)2 -SCN, -COOCH3 or -OCH(CH3)COOC2H5, and n is an integer of 1 to 5, said R3 being the same or different when n is an integer of 2 to 5. In particular the derivative is, selected from 2-tert.-butyl-4-chloro-5-mercapto-3(2H)pyridazinone and …