(S)-(-)-N-Benzyl-1-phenylethylamine → (S)-3-[2-(4-Acetylaminophenyl)ethyl]-3-hydroxy-4-methylpentanoic Acid (S)-N-Benzyl-alpha-methylbenzylamine Salt

Participants

Reaction Conditions

Reaction Steps

Ethanol (125 g) was added to (+/−)-3-[2-(4-acetylaminophenyl)ethyl]-3-hydroxy-4-methylpentanoic acid (11a, 25 g, 85 mmol) and the resulting solution stirred at 20° C. (S)-N-Benzyl-α-methylbenzylamine (21, 22.5 g, 106 mmol) was added to the solution and the resulting mixture allowed to stir at 20° C. for 23 hours. The mixture was filtered and the product washed with ethanol (10 mL) and vacuum dried at ambient temperature to give (S)-3-[2-(4-acetylaminophenyl)ethyl]-3-hydroxy-4-methylpentanoic acid (S)-N-benzyl-α-methylbenzylamine salt (22a): 18.6 g (36.8 mmol, 43% yield or 86% of theory); Chiral assay (HPLC): 99.2 area % (S) isomer 23a; mp: 152-154° C.

Provenance & Evidence