Antihypertensive tetrahydropyridine 3-cyano 5-carboxylic acid esters

Claim 1

A 1,2,3,4-tetrahydropyridine of the formula ##STR31## in which R 1 represents phenyl or naphthyl optionally substituted by 1 or 2 identical or different substituents from the group consisting of phenyl, straight-chain or branched alkyl having 1 to 8 carbon atoms, cycloalkyl having 3 to 7 carbon atoms, alkoxy having 1 to 4 carbon atoms, tri-tetra- and pentamethylene, dioxamethylene, halogen, trifluoromethyl, trifluoro-methoxy, difluoromethoxy, tetrafluoroethoxy or cyano, R 2 represents a straight-chain, branched or cyclic, saturated or unsaturated hydrocarbon radical having up to 20 carbon atoms, which is optionally interrupted by one oxygen or sulphur atom in the chain and/or which is optionally substituted by halogen, cyano, hydroxyl, α-, β- or γ-pyridyl, phenyl, phenoxy or phenylthio, it being possible for the phenyl groups to be substituted by halogen, cyano, dialkylamino having 1 to 4 carbon atoms in each alkyl radical, alkoxy having 1 to 4 carbon atoms, alkyl having 1 to 4 carbon atoms, trifluoromethyl or trifluoromethoxy, or by an amino group which in turn is substituted by two identical or different substituents from the group consisting of alkyl having 1 to 4 carbon atoms, phenyl or benzyl, R 3 and R 5 , which are identical or different, each represent hydrogen, a straight-chain or branched alkyl radical having up to 4 carbon atoms, a phenyl radical or a benzyl radical, and R 4 represents hydrogen, a straight-chain or branched alkyl radical having up to 4 carbon atoms which is optionally interrupted by an oxygen atom, a phenyl radical or a benzyl radical, or a salt thereof with a physiologically tolerated acid.