Pamidronic Acid → Sodium (3-amino-1-hydroxy-1-phosphonopropyl)phosphonate

Participants

Reaction Conditions

Reaction Steps

77.1 g of 3-amino-1-hydroxypropane-1,1-diphosphonic acid are suspended in 250 ml of demineralised water, and while stirring vigorously, 65.6 g of 40% aqueous sodium hydroxide solution are added. The rate of addition thereof is so regulated that the temperature of the reaction mixture during neutralisation rises to approximately 50° C. The reaction mixture is heated to 52° C. and inoculated and allowed to cool slowly to room temperature and left to stand overnight; the resulting salt cake is filtered with suction, washed with 120 ml of approximately 66% methanol and dried under 10-20 mbar at 150° C. until the weight is constant. Disodium 3-amino-1-hydroxypropane-1,1-diphosphonate is obtained in a substantially anhydrous crystalline form (modification A). This form is characterised by the following lattice spacings (d-values) and relative line intensities (intensities) of its X-ray powder pattern (camera according to Guinier-de-Wolff, radiation source: copper-Kα):

Provenance & Evidence