Role of the solvent in optical resolution of trans-chrysanthemic acid via diastereomeric salt formation with (1R,2R)-1-(4-nitrophenyl)-2-dimethylaminopropane-1,3-diol

Optical resolution of trans-chrysanthemic acid via diastereomeric salt form ation with (1R,2R)-1-(4-nitrophenyl)-2-dimethylaminopropane-1,3-diol (DMAD) has been studied in different solvents. Ether type solvents containing MeO H were found to be preferred. The role of MeOH was interpreted on the basis of powder and single crystal X-ray diffraction and DSC/TG measurements. We found that MeOH was incorporated into the crystals of the less soluble dia stereomer salt of the 1R acid with DMAD in a non-stochiometric amount and p ostulated to promote nucleation and crystal growth.