The reduction of 4-phenylbenzophenone (I) with NaBH4 in ethanol gives 4-phenylbenzhydrol (II), which is then condensed with imidazole (III) by means of SOCl2 in acetonitrile.

The reduction of 4-phenylbenzophenone (I) with NaBH4 in ethanol gives 4-phenylbenzhydrol (II), which is then condensed with imidazole (III) by means of SOCl2 in acetonitrile.

The reduction of 4-phenylbenzophenone (I) with NaBH4 in ethanol gives 4-phenylbenzhydrol (II), which is then condensed with imidazole (III) by means of SOCl2 in acetonitrile.

The reduction of 4-phenylbenzophenone (I) with NaBH4 in ethanol gives 4-phenylbenzhydrol (II), which is then condensed with imidazole (III) by means of SOCl2 in acetonitrile.

The condensation of (S)-1-(4-bromophenyl)-1-phenylmethylamine (S)-(I) with phenylboronic acid (II) by means of Pd(OAc)2, PPh3 and Na2CO3 in propanol/water gives the corresponding biphenyl derivative (S)-(III), which is condensed with 3-bromopropanal dimethylacetal (IV) by means of K2CO3 in DMF yielding the secondary amine (S)-(V). The reaction of (S)-(V) with refluxing butyl formate (VI) affords the formamide (S)-(VII), which is cyclized with ammonium acetate in acetic acid to furnish the (S)-enantiomer of the target compound. The corresponding (R)-enantiomer has been obtained by the same reaction sequence but starting from (R)-1-(4-bromophenyl)-1-phenylmethylamine (R)-(I).