合成路线1

The chiral intermediate (X) was synthesized from 3-cyanobenzoic acid (I) through the following sequence. Hydrogenation of the cyano group over Raney-nickel provided 3-(aminomethyl)benzoic acid (II), which was protected as the tert-buyl carbamate (III) with Boc2O. Subsequent hydrogenation of the benzene ring of (III) over PtO2 yielded the racemic amino acid (IV), predominantly as the cis isomer. The chiral resolution of (IV) with (S)-a-methylbenzyl amine (V) in EtOAc provided the optically pure 1(R),3(S) compound (VI), which was then reduced with borane in THF. The resulting aminoalcohol (VII), after conversion to mesylate (VIII) with methanesulfonyl chloride, was treated with NaN3 to give azide (IX), and this was then reduced to amine (X) with H2 over Pd/C.