Why is it necessary to resolve chiral pharmaceuticals (why cant we just use racemic versions)?What are the important criteria of a good resolving reagent?In particular why is (S)- methylbenzylamine a suitable resolving agent for ibuprofen NH3NH2(S,S) Salt- Insoluable in Aqueous SolutionForms PrecipitateCH3HORacemic-(+)-Ibuprofen(S)-(-)-methylbenzyl amineCH3NH3(R,S) Salt- Soluable in Aqueous Solution CH3CH3H2SO4NH3(S)-(+)-ibuprofen(not water soluable)(S,) SaltNH3HSO4ammonium salt(water soluable)Oll.

The separation of two enantiomers is called a resolution. We know that enantiomers have different rates of reactivities with optically active reagents. While dealing with chiral pharmaceuticals, it is very important to distinguish a single enantiomer from the racemic mixture, since the two enantiomers may differ widely in their dosages, efficacies, side-effect profiles, and indicated usage. So, if we simply use the racemic version, it might happen that one of the drugs creates some toxic effects on reacting within the body. Thus, to avoid adverse effects and optimize the therapeutic value of enantiomeric drugs, it is necessary to resolve the chiral pharmaceuticals.The important criteria of a good resolving agent: 1. The agent itself must be enantiomerically pure 2. The reagent must be reactive towards substance to be resolved 3. The reagent must be readily available and cost effective 4. The two enantiomers formed by the reaction between the resolving agent and the substance to be resolved, should be easily separable (S)- methylbenzylamine a suitable resolving agent for ibuprofen because: 1. It contains a chiral center and is enantiomerically pure 2. The -NH2 group on (S)-(-)-methylbenzyl amine is reactive towards the -COOH group on Ibuprofen. 3. The reaction products formed are readily separable since one of the enantiomers is water soluble and forms crystals, while the other is non-soluble in water. They can be separated simply by filtration.