Abstract: A 2-cyanaziridine derivative of the formula ##STR1## wherein R' is a straight-chained or branched, saturated or mono- or polyunsaturated aliphatic hydrocarbon radical with up to 8 carbon atoms, which is substituted by an aromatic nitrogen-containing heterocyclic radical with 5 or 6 ring-members and 1, 2 or 3 nitrogen atoms optionally substituted by halogen, alkoxy with up to 8 carbon atoms, alkyl with up to 8 carbon atoms, hydroxyl, carbalkoxy with up to 9 carbon atoms, carbamoyl, dialkylamino the alkyl moieties of which having up to 8 carbon atoms, cycloalkylamino, the cycloalkyl moiety having 3-10 carbon atoms, acetylamino, nitro, cyano, acetyl, alkylthio with up to 8 carbon atoms, alkylsulphinyl with up to 8 carbon atoms, alkylsulphonyl with up to 8 carbon atoms, sulphamoyl, phenyl, trifluoromethyl, phenoxy, acetoxy or methylenedioxy;or a pharmacologically acceptable salt thereof, exhibits immune stimulating activity.

Abstract: Aziridine-2-carboxylic acid derivatives of the formula ##STR1## wherein X is a carboxyl, nitrile, alkoxycarbonyl or carbamoyl group, andR and R.sup.1 are various organic radicals; or pharmacologically acceptable salts thereof, exhibit marked immunostimulant activity, especially in conjunction with added chemotherapeutic agents such as a penicillin, a cephalosporin, a nitrofuran or chloramphenicol. Those compounds are new where X is a cyano group or an alkoxycarbonyl radical and R.sub.1 is a hydrogen atom, but R' is not an unsubstituted alkyl radical or an alkyl radical substituted by hydroxyl, alkoxy, dialkylamino, phenyl, 4-chlorophenyl or 4-methoxyphenyl or a vinyl radical substituted by a phenyl or methyl radical, or a cycloalkyl radical, a phenyl, a 4-chlorophenyl, a 4-methoxyphenyl, an s-triazinyl or a pyridinyl radical; or where X is a carbamoyl group and R.sub.

Abstract: Aziridine-2-carboxylic acid derivatives of the formula ##STR1## wherein X is a carboxyl, nitrile, alkoxycarbonyl or carbamoyl group, andR and R.sup.1 are various organic radicals, or pharmacologically acceptable salts thereof, exhibit marked immunostimulant activity, especially in conjunction with added chemotherapeutic agents such as a penicillin, a cephalosporin, a nitrofuran or chloramphenicol. Those compounds are new where X is a cyano group or an alkoxycarbonyl radical and R.sub.1 is a hydrogen atom, but R' is not an unsubstituted alkyl radical or an alkyl radical substituted by hydroxyl, alkoxy, dialkylamino, phenyl, 4-chlorophenyl or 4-methoxyphenyl or a vinyl radical substituted by a phenyl or methyl radical, or a cycloalkyl radical, a phenyl a 4-chlorophenyl, a 4-methoxyphenyl, an s-triazinyl or a pyridinyl radical; or where X is a carbamoyl group and R.sub.