合成路线1

Similarly, the condensation of N-benzyl-4-piperidone (I) with KCN in the presence of NH4Cl provides amino nitrile (II), which is further hydrolyzed to amide (III) with 95% H2SO4. Cyclization of amino amide (III) with formamide under acidic conditions yields the spiro imidazolinone (IV), which is further reduced to imidazolidinone (V) employing NaBH4 in hot MeOH. Debenzylation of (V) with H2 and Pd/C provides 1,3,8-triazaspiro[4,5]decan-4-one (VI). Then, alkylation of (VI) with 4'-fluoro-4-chlorobutyrophenone (VII) by means of K2CO3 and catalytic KI in methyl isobutyl ketone furnishes (VIII). The imidazolidinone ring of (VIII) is finally methylated with iodomethane and KOH to produce the title compound (2).