Nitrosation of the benzocycloheptanone (I) with isoamyl nitrite furnishes the keto oxime (II). Subsequent ring closure of (II) with pyridine-3-carboxaldehyde (III) and ammonium acetate produces the N-hydroxy imidazole derivative (IV). Then, reduction of the N-hydroxy group of (IV) is performed by treatment PCl3 in DMF