Direct enantioseparation of 1-(2-hydroxyphenyl) ethylamines via diastereomeric salt formation: chiral recognition mechanism based on the crystal structure
In this study, the direct enantioseparation of unprotected 1-(2-hydroxyphenyl)ethylamines (1a and 1b) viadiastereomericsaltformation is reported. After the one-pot synthesis of racemic 1, the screening of seven acidic chiral resolving agents showed that the extraction of (S)-naproxen (6) with dibenzoyl-L-tartaric acid (5) afforded the corresponding 1 : 1 diastereomeric salts that were suitable for