反应详情

4 g. 4-Amino-1-hydroxybutane-1,1-diphosphonic acid are dissolved in 64 ml. 1N aqueous sodium hydroxide solution, mixed with 3.8 ml. isovaleraldehyde and, after the addition of 2.5 g. of 10% palladium-charcoal, hydrogenated at a pressure of 5 bar. The course of the reaction is monitored electrophoretically until the starting material has disappeared. The reaction mixture is filtered, acidified with Amberlite R 120 (H+ form) and evaporated until crystallisation commences, 1.3 g. of crystals thus being obtained in a yield of 20% of theory; m.p. 225°-227° C. (decomp.); Mrel =0.39. 1-Hydroxy-4-(N-3-methylbutylamino)-butane-1,1-diphosphonic acid remaining in the mother liquor, which is formed as an intermediate, can be used again for the reductive alkylation.

1. filtrationThe reaction mixture is filtered
2. customevaporated until crystallisation commences, 1.3 g
3. customof crystals thus being obtained in a yield of 20% of theory