The Family Approach to the Resolution of Racemates

Rational approach to the selection of conditions for diastereomeric resolution of chiral amines by diacid resolving agents

“…Several methods for the selection of the appropriate resolution system employing theoretical techniques have been attempted: computer-assisted models, examination of the crystal structure of diastereomer salts, study of energy differences between diastereomer salts and empirical correlations. [5][6][7][8] However, the resolution system is still essentially selected on the basis of experimental trial and error. 5,6 Fredga et al 9 were the first to try to systematise this experimental approach, using the one equivalent method to screen, at the 1 ml scale, different resolving agents, resolution solvents and racemic substrate concentrations (in a range from 0.1 to 1.0 M).…”

The effect of the eutectic composition on the outcome of kinetically and thermodynamically controlled resolutions that are based on the formation of diastereomers

“…In these instances, a potential solution would be the application of a mixture of structurally related resolving agents, as this concept has been proven by Dutch researchers. 38,39 We also wished to investigate if the limitations caused by eutectic compositions of the compounds involved in a particular resolution could be avoided in a simple manner, namely by changing the temperature of the crystallization of the corresponding diastereomers. The resolution of mandelic acid with 1 equiv of (R)-Pregabalin was chosen as the model reaction.…”

Recrystallization of Enantiomers from Conglomerates

“…Let us just mention the Marckwald's method (Marckwald, 1896), the Pope and Peachey's method (Pope & Peachey, 1899) and more recently the Dutch resolution (Vries et al, 1998), (Kaptein et al, 2000). Note also that the accurate determination of the phase diagrams under the conditions of the experimental process allows an optimization of the resolution (Marchand et al, 2004).…”