Abstract: A complex containing three moles of alpha-amino-e-caprolactam and one mol of magnesium chloride, as such or containing also one mol of ethanol or isopropanol. The complex is useful for resolution of the alpha-amino-e-caprolactam optical isomers, in supersaturated solution containing ethanol, isopropanol, or methanol by contacting such solution with crystals of the complex.

Abstract: Resolution of .alpha.-amino-.epsilon.-caprolactam with simultaneous racemization of the undesired D-.alpha.-amino-.epsilon.-caprolactam enantiomer is effected by forming a coordinately saturated .alpha.-amino-.epsilon.-caprolactam complex with NiCl.sub.2, preferably crystallizing the L-.alpha.-amino-.epsilon.-caprolactam complex in the presence of fine seed crystals of L-.alpha.-amino-.epsilon.-caprolactam complex of NiCl.sub.2 and catalytic amounts of a strong base selected from the alkoxides or hydroxides of Ni(II) and recovering L-.alpha.-amino-.epsilon.-caprolactam hydrochloride from the crystalline product.

Abstract: Resolution of .alpha.-amino-.epsilon.-caprolactam with simultaneous racemization of the undesired .alpha.-aminocaprolactam enantiomer is effected by preferentially crystallizing the L- (or D-) .alpha.-amino-caprolactam compound in the presence of a racemization catalyst. In a narrower embodiment racemization of .alpha.-amino-.epsilon.-caprolactam is effected by alternate routes of forming a coordinately saturated aminolactam-metal complex and reacting with a strong base or reacting a mixture of an aminolactam salt and aminolactam free base with a chelating carbonyl compound and a metal ion or reacting a mixture of an aminolactam salt and aminolactam free base in the presence of a salen derivative complex.