合成路线1

Intermediate amine (X) was prepared as follows: Alkylation of 3,4-(methylenedioxy)phenylacetone (I) with iodoacetaldehyde diethyl acetal (II) provided racemic ketone (III), which was diastereoselectively reduced to alcohol (IV) with L-Selectride. Resolution was effected by esterification with (R)-alpha-methoxyphenylacetic acid, followed by chromatographic separation of the diastereoisomeric esters. The required isomer (V) was hydrolyzed under alkaline conditions and the resulting alcohol was converted to mesylate (VI) by treatment with methanesulfonyl chloride and Et3N. Displacement of the mesylate group of (VI) with NaN3 with inversion of the configuration yielded azide (VII), which was reduced to amine (VIII) using PPh3. Then, reductive condensation of (VIII) with 2-naphthalenecarboxaldehyde in the presence of NaBH4 afforded the secondary amine (X).