Facile routes for the preparation of 3,4-disubstituted 1,3-oxazolidines and 1,2,5-trisubstituted imidazolidin-4-ones

Facile, alternative synthetic routes to (RS)-, (R)-, and (S)-3-benzyl-N-(2,6-dimethylphenyl)-1,3-oxazolidine-4-carboxamides (6), a chiral oxazolidine derivative of tocainide, are reported. The synthetic routes described herein also afforded (RS)-, (R)-, and (S)-11, which present the imidazolidin-4-one core and belong to a class of compounds interesting for their biological activities. All the final compounds and intermediates were fully characterized. Enantiomeric excesses of homochiral 6 and 11 were determined by capillary electrophoresis analysis using 2-hydroxypropyl-beta-cyclodextrin or highly sulfated gamma-cyclodextrin as chiral selectors.