FOERFARANDE FOER FRAMSTAELLNING AV NYA DIFOSFONSYRADERIVAT

The present invention provides disphosphonates of the general formula: (I) wherein R1 is a straight-chain or branched, saturated or unsaturated aliphatic hydrocarbon radical of 1-9 carbon atoms which is optionally substituted by phenyl or cyclohexyl, R2 is cyclohexyl or cyclohexylmethyl, benzyl or a straight-chained or branched, saturated or unsaturated aliphatic hydrocarbon of 4 to 18 carbon atoms which is optionally substituted by phenyl or oxygen wherein the oxygen can be esterified or etherified, R3 is hydrogen or a straight-chain or branched alkyl of 1-4 carbon atoms, X is a straight-chain or branched alkylene chain of 1-6 carbon atoms and Y is hydrogen, hydroxyl or an amino group optionally substituted by alkyl radicals of 1-6 carbon atoms; as well as the pharmacologically acceptable salts thereof. The present invention also provides processes for the preparation of these diphosphonic acid derivatives and pharmaceutical compositions containing them for the prophyllaxis treatment of diseases or disturbances of calcium metabolism such as osteoporsis, Pagets disease, Bechterew's disease, bone metastases, urolithiasis, heterotropic ossifications, rheumatoid arthritis, osteoarthritis and degenerative arthrosis.