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Diastereotopic analysis of mesoridazine besylate (serentil)
Author(s) -
Morrow Ryan J.,
Millership Jeff S.,
Collier Paul S.
Publication year - 2004
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.20073
Subject(s) - diastereomer , chemistry , enantiomer , reagent , benzylamine , base (topology) , crystallization , proton nmr , free base , chirality (physics) , stereochemistry , medicinal chemistry , salt (chemistry) , organic chemistry , mathematical analysis , nambu–jona lasinio model , mathematics , chiral symmetry breaking , physics , quantum mechanics , quark
NMR studies were conducted with the aim of determining the diastereoisomeric ratio of a commercially supplied sample of mesoridazine (MES) and to compare the results with a freshly synthesised sample of MES. The results indicated that the commercially supplied MES consisted almost entirely of one diastereoisomeric pair, which was in agreement with previous findings reported by Eap et al. (J Chromatogr 669:271–279, 1995). The synthesised sample of MES was analysed by NMR in two stages: 1) as the initial product isolated as the free base from the direct synthesis, and 2) as the free base isolated from the crystallised besylate salt of the synthetic product. The NMR results show that the initial synthetic product consisted of two equal pairs of diastereoisomers. The diastereoisomeric pairs were further separated by the addition of the chiral shift reagent (R)‐(–)‐N‐(3,5 dinitrobenzoyl)‐α‐benzylamine to reveal equal quantities of all four enantiomers, clearly observed at the methyl sulfoxide proton peak of the NMR scan. The sample obtained from the crystallisation of MES besylate, however, indicated a significant difference, with a diastereoisomeric ratio of 75:25. The results suggest that MES besylate undergoes preferential crystallisation of one pair of diastereoisomers, with the other pair remaining in solution. Chirality 16:534–540, 2004. © 2004 Wiley‐Liss, Inc.