Patent ID: 7078393

Claim:
A method for preparing 1-hydroxy-1,1-diphosphonic acid compounds of the general formula I and/or of their pharmacologically compatible salts wherein R 1 is hydrogen, OH, NO 2 , Cl, F, Br, C 1 –C 6 alkyl optionally substituted by halogen, amino, and/or aminoalky, C 1 –C 6 alkoxy, aryl, heteroaryl, a group NR 3 R 4 in which R 3 and R 4 are identical or different and represent hydrogen, C 1 –C 6 alkyl, halogen-substituted alkyl, hydroxy-C 1 –C 6 alkyl, R 2 is hydrogen, halogen, amino that is optionally substituted, C 1 –C 6 alkyl optionally substituted by halogen, amino, and/or aminoalky, C 1 –C 6 alkoxy, aryl, heteroaryl, Y O, S, or NH, Z C 1 –C 5 alkylene optionally substituted by amino groups, m and n are 0 or 1, under the condition that when n=1 then also m=1, the method comprising the steps of: a) reacting a compound of the formula II wherein R 1 , R 2 , Y, Z, m, and n are defined as above, with a compound of the formula III P(OSiR 5 3 ) 3-p R 6 p (III) wherein R 5 is a C 1 –C 4 alkyl group; R 6 is a C 1 –C 6 alkoxy group; p is 0, 1, or 2; and b) hydrolyzing the reaction product of step a).