合成路线1

Horner-Emmons reaction of 1-benzyl-4-piperidone (I) with triethyl 4-phosphonocrotonate (II) afforded the (piperidinylidene)butenoate (III). Catalytic hydrogenation of the double bond of (III) with concomitant N-debenzylation yielded the piperidinylbutanoate (IV). After reprotection as the N-benzyl derivative (V), reduction of the ester function of (V) using LiAlH4 gave alcohol (VI), which was further converted to mesylate (VII). Displacement of the mesylate group of (VII) with diethylamine produced diamine (VIII). The N-benzyl group of (VIII) was then deprotected by transfer hydrogenation to furnish piperidine (IX). The chloroacetyl derivative (XI) was prepared by acylation of iminodibenzyl (X) with chloroacetyl chloride. Chloride (XI) was finally condensed with piperidine (IX) in the presence of Na2CO3 and NaI to afford the title compound.