Abstract: Mixtures of m- and p-dichlorobenzene can be separated by treating such mixtures in the liquid phase with a pentasil zeolite at from 20.degree. to 250.degree. C., a filtrate enriched in m-dichlorobenzene being removed and the p-dichlorobenzene being obtained by desorption of the pentasil zeolite. The pentasil zeolites may contain, as exchangeable cations, protons, cations of the first or second main group of the Mendeleev Periodic System, cations of the rare earth metals or a mixture of a plurality thereof. In order to prepare the liquid phase a solvent is used that belongs to the group of cyclic saturated hydrocarbons having 5 to 15 carbon atoms, alkyl-substituted aromatic hydrocarbons having 8 to 12 carbon atoms, and halogen-substituted aromatic hydrocarbons having 6 to 10 carbon atoms and 1 to 3 halogen atoms. The solvents ethylbenzene, chlorobenzene, p-xylene, p-chlorotoluene and dichlorobenzene are excepted. A mixture of a plurality of these solvents may also be used.

Abstract: The invention relates to new optically active amino acid derivatives of the general formula (I) ##STR1## in which n, R, R.sub.1, R.sub.2, R.sub.3, X and A have the meaning given in the description, which amino acid derivatives contain sulphoxide or sulphone groups, to two basic synthetic routes for the preparation from sulphur-containing amino acids, to the polymerization of these monomers and to the use of the polymers as optically active adsorbents for chromatographic resolution of racemates to give the enantiomers.

Abstract: .alpha.-Fluoro-substituted N-acryloylamino acid derivatives of the formula ##STR1## are used to make polymers optionally for chromatographic resolution of racemates into their enantiomers. The fluorine atom improves performance in many instances.

Abstract: The invention relates to optically active, pressurestable bead polymers containing fillers, and their use as adsorbents for the chromatographic resolution of enantiomeric mixtures (or racemates) into their enantiomers.

Abstract: The invention relates to new optically active sulphur-containing amino acid derivatives, a process for their preparation, their polymerisation to give optically active polymers and the use of these optically active polymers as adsorbents for chromatographic separation of racemates into enantiomers.

Abstract: .alpha.-Fluoro-substituted N-acryloylamino acid derivatives of the formula ##STR1## are used to make polymers optionally for chromatographic resolution of racemates into their enantiomers. The fluorine atom improves performance in many instances.

Abstract: An optically active N-(meth)acryloyl amino acid amide of the formula ##STR1## in which R is hydrogen or methyl,R.sub.1 represents an optionally substituted alkyl, cycloalkyl, aralkyl, aryl or heteroaryl radical,R.sub.3 represents hydrogen or denotes together with R.sub.1 a tri- or tetramethylene group;X denotes oxygen or a NR.sub.4 -group wherein R.sub.4 represents hydrogen or alkyl or denotes together with R.sub.2 and the nitrogen atom a 5- to 7-membered ring which ring is optionally substituted by the group COO-alkyl (1-6 carbon atoms) or by one or two alkyl radicals (1-4 carbon atoms) andR.sub.2 denotes a strongly space-filling hydrocarbon radical.The amide is polymerized and optionally bound to a support such as silica, and can then be used for the chromatographic separation of racemic mixtures of pharmacologically active compounds.

Abstract: The invention relates to optically active homo- and copolymers made from optically active (meth)acrylamides, the polymers being immobilized on silica gel, a process for their preparation, and their use as adsorbents, in particular as the stationary phase for chromatographic racemate resolution.

Abstract: In the chromatographic separation of a mixture of antipodes of optically active chemicals by passing a solution of such mixture over an optically active adsorbent to effect adsorption, and then eluting the adsorbed material, the improvement which comprises employing as the adsorbent particles of an optically active and cross-linked polymer containing the repeating structural unit ##STR1## in which R.sup.1 represents hydrogen or methyl, andR.sup.2 represents one of the stereoisomers of the eight possible stereoisomeric forms of each of the optically active radicals of the formulae ##STR2## Improved separation results. The pure monomers are also new.

Abstract: The invention relates to optically active homo- and copolymers made from optically active (meth)acrylamides, the polymers being immobilized on silica gel, a process for their preparation, and their use as adsorbents, in particular as the stationary phase for chromatographic racemate resolution.

Abstract: Pure enantiomers of 5-nitrodihydropyridine of the formula ##STR1## are mixed, wherein one of the enantiomers has a high vasodilative action and a low negative inotropic activity on heart muscle, the other enantiomer has a low vasoconstrictive action and a high positive inotropic activity on heart muscle, the mixture being high in vasodilative activity and in positive inotropic activity on heart muscle.