合成路线1

Friedel-Crafts acylation of acetanilide (I) with propionyl chloride in the presence of AlCl3 afforded 4'-(acetamido)propiophenone (II). Subsequent Mannich reaction of (II) with dimethylamine hydrochloride and formaldehyde produced the aminoketone (III). Quaternization of the tertiary amine of (III) with MeI, followed by displacement of the resulting ammonium salt (IV) with KCN yielded the intermediate ketonitrile (V). In alternative procedure, nitrile (V) was prepared by acylation of acetanilide (I) with 3-chloro-2-methylpropionyl chloride, and further displacement of the resulting alpha-chloroketone (VI) with KCN. Acid hydrolysis of both nitrile and acetamido groups of (V) provided ketoacid (VII), which was cyclized with hydrazine to give pyridazinone (VIII). Finally, acylation of the amino group of (VIII) by means of pyridine-4-carbonyl chloride furnished the title amide.