Method of producing 1-hydroxy-1,1-diphosphonic acid compounds

The invention relates to a method of producing the 1-hydroxy-1,1-diphosphonic acid compounds of general formula (I), and/or the pharmacologically acceptable salts thereof, in which formula R 1 represents hydrogen, OH, NO 2 , Cl, F, Br, C 1 -C 6 alkyl that may be substituted with halogen, amine and/or aminoalkyl, C 1-6 alkoxy, aryl, heteroaryl, a group NR 3 R 4 , wherein R 3 and R 4 may be the same or different and represent hydrogen, C 1 -C 6 alkyl, halogen-substituted alkyl, hydroxy-C 1 -alkyl; R 2 represents hydrogen, halogen, amine that may be substituted, C 1 -C 6 alkyl that may be substituted with halogen, amine and/or aminoalkyl, C 1 -C 6 alkoxy, aryl, heteroaryl; Y represents O, S or NH; Z represents C 1 -C 5 alkylene that may be substituted with amine groups, and m and n are 0 or 1, with the proviso that if n=1, m=1. According to the inventive method, a compound of formula (II), wherein R 1 , R 2 , Y, Z, m and n are defined as above, is reacted with a compound of the formula P(OSiR 5 3 ) 3-p R 6 p , wherein R 5 represents a C 1 -C 4 alkyl group, R 6 represents a C 1 -C 6 alkyloxy group, and p is 0, 1 or 2. The reaction product is hydrolyzed in a manner known pre se and is optionally converted to the corresponding salts.