合成路线1

An alternative synthesis starting from the chiral precursor N-Boc-(R)-phenylglycine (IX) was reported. Borane reduction of (IX) provided the N-Boc aminoalcohol (X), which was activated as the mesylate (XI) by reaction with methanesulfonyl chloride in pyridine, yielding (XI). Displacement of the mesylate group of (XI) with NaCN furnished the Boc-aminonitrile (XII). Hydrolysis of the nitrile group of (XII) with concomitant N-Boc group cleavage under acidic conditions gave aminoacid (XIII). This was reduced to amino alcohol (XIV) using borane in THF. Eschweiler-Clarke methylation of aminoalcohol (XIV) yielded the dimethyl amine (XV). This was finally condensed with 1-fluoronaphthalene (VIII) to produce the title naphthyl ether. The [14C]-labeled compound was similarly prepared employing 14C-sodium cyanide.