合成路线1

The reaction of isovanillin with hydroxylamine sulfate and NaOH in refluxing ethanol/water gives the corresponding oxime (II), which is reduced with Raney-Ni and NaOH in the same solvent yielding the benzylamine (III). The protection of the amino group of (III) with benzyloxycarbonyl chloride affords the carbamate (IV), which is condensed with ethyl bromoacetate (IV) by means of K2CO3 in refluxing 2-butanone to give the ester (VI). The hydrolysis of (VI) with NaOH in hot methanol/water yields the corresponding acid (VII), which is condensed with 1-benzylpiperazine (VIII) by means of ethyl chloroformate in THF to afford the piperazide (IX). The deprotection of the amino group of (IX) with H2 over Pd/C in hot ethanol gives the benzylamine (X), which is finally condensed with 4,5-dichloropyridazin-3(2H)-one (XI) by means of triethylamine in refluxing ethanol/water.