| 摘要 |
An improved process is described for the preparation of 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid (ABP)or salts thereof which comprises: (a) reacting 4-aminobutyric acid with a mixture of phosphorous acid and PCl3 in the presence of methanesulfonic acid; (b) contacting the mixture from Step (a) with an aqueous hydrolysis mixture, wherein the pH is maintained in the range of 4 to 10 during the contacting; and (c) recovering said 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid or salts thereof. s |
