Ketone (I) was reduced with sodium borohydride in methanol to alcohol (II), which was then converted into chloride (III) on treatment with thionyl chloride in cooled toluene. Alkylation of piperazine (IV) with chloride (III) in the presence of triethylamine gave V. Finally, piperazine (V) was condensed with 4-pyridylacetic acid (VI) in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (DEC), 1-hydroxybenzotriazole (HOBt), and N-methylmorpholine in DMF to afford the target amide.
Treatment of propargyl alcohol (I) with two equivalents of butyllithium in THF, followed by chlorotrimethylsilane, and then with methanol and a catalytic amount of distannoxane, gave 3-(trimethylsilyl)-2-propyn-1-ol (II). Partial reduction of acetylenic triple bond with sodium bis(2-methoxyethoxy)aluminum hydride afforded the expected (E)-olefin (III), which on treatment with methanesulfonyl chloride and triethylamine in dichloromethane provided mesylate (IV). Finally, alkylation of 1-deoxynojirimycin (V) with mesylate (IV) in the presence of triethylamine gave the title compound.