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Enhanced efficiency due to the use of achiral additives in the optical resolution of 1‐phenylethylamine by its glutaric acid derivative
Author(s) -
Schindler József,
Egressy Márton,
Bereczki Laura,
Pokol György,
Fogassy Elemér,
Marthi Katalin
Publication year - 2007
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20377
Subject(s) - chemistry , thiourea , glutaric acid , malonic acid , succinic acid , resolution (logic) , derivative (finance) , dicarboxylic acid , benzoic acid , chirality (physics) , derivatization , malonate , organic chemistry , oxalic acid , enantiomer , high performance liquid chromatography , chiral symmetry breaking , physics , quantum mechanics , artificial intelligence , computer science , financial economics , nambu–jona lasinio model , economics , quark
Racemic 1‐phenylethylamine was optically resolved by its own derivative formed with glutaric acid namely (+)‐( R ) ‐N‐ (1‐phenylethyl)glutaramic acid. The amide acid resolving agent was synthesized from (+)‐( R )‐1‐phenylethylamine by N‐derivatization. The glutaric acid derivative was the next in a homologous series of dicarboxilic acid derivatized resolving agents of racemic 1‐phenylethylamine. Resolution results obtained with the oxalic, malonic, and succinic acid derivatives were previously discussed 1 . Each of the above derivative resolving agents could be successfully applied as resolving agents of 1‐phenylethylamine. The efficiency of the present optical resolution using (+)‐( R ) ‐N‐ (1‐phenylethyl)glutaramic acid resolving agent was remarkably inferior to the results obtained by its shorter chained homologues 1 . Use of achiral additives, like urea, thiourea, N ‐methylurea, and N,N′‐ dimethylurea caused large increase in the efficiency of the resolution by (+)‐( R ) ‐N‐ (1‐phenylethyl)glutaramic acid resolving agent. Precipitated salts obtained in the resolutions performed in the presence of the additives were investigated by thermoanalysis, X‐ray powder diffraction, and optical microscopy. Based on the analytical data, the improvement of the resolution results was attributed to the influence of the additives on the crystal nucleation processes of the diasteromeric salts. Chirality, 2007. © 2007 Wiley‐Liss, Inc.