Diphosphonic acid derivatives, process for their preparation and medicines containing those compounds.

Last alkyl diphosphonic the general formula Iin theHet is a heteroaromatic five-membered ring with 2-3 heteroatoms teilwwise hydrogenated and optionally one or may be substituted by alkyl, alkoxy, phenyl, cyclohexyl, Cyclohexylmetyhyl, halogen or the amino group of multiple, where two adjacent Alkylsubstituerten may also together form a ring,Y is hydrogen or lower alkyl,X is hydrogen, hydroxy or optionally substituted by lower alkyl amino, and, R is hydrogen or lower alkyl, with the proviso that Het must not represent the pyrazole ring,as well as their pharmacologically acceptable salts, Procedure for their preparation and pharmaceutical compositions containing these compounds, for the treatment of calcium metabolism disturbances.