The condensation between cyclohexanone (I) and dimethyl itaconate (II) in the presence of NaOMe in cold Et2O afforded the spirobutenolide (III) together with some hydrolyzed product (IV). A further hydrolytic treatment with aqueous NaOH provided acid (IV), which was then converted to acid chloride (V) by treatment with PCl5 in refluxing cyclohexane. Reaction of this acid chloride with N-(4-fluorophenyl)piperazine in CH2Cl2 at 0 C produced the title amide.
The condensation between cyclohexanone (I) and dimethyl itaconate (II) in the presence of NaOMe in cold Et2O afforded the spirobutenolide (III) together with some hydrolyzed product (IV). A further hydrolytic treatment with aqueous NaOH provided acid (IV), which was then converted to acid chloride (V) by treatment with PCl5 in refluxing cyclohexane. Reaction of this acid chloride with N-(2-methoxyphenyl)piperazine in CH2Cl2 at 0 C produced the title amide.