合成路线1

Reaction of piperonyloyl chloride (I) with N,O-dimethylhydroxylamine gives rise to the Weinreb amide (II). This is then condensed with the lithium anion of 2-picoline (III) to produce ketone (IV). Nitrosation of (IV) with NaNO2/HCl leads to keto oxime (V). Subsequent cyclization of (V) with p-formylbenzonitrile (VI) in the presence of ammonium acetate in AcOH affords the N-hydroxy imidazole (VII), which is further reduced to the triaryl imidazole (VIII) by means of triethyl phosphite in DMF. The cyano group of (VIII) is then hydrolyzed under acidic conditions to provide carboxylic acid (IX). After activation of (IX) as the corresponding acid chloride (X), treatment with ammonium hydroxide in THF yields the target carboxamide (1,2).