Acetic Anhydride → Fosmidomycin

Beteiligte Stoffe

Reaktionsschritte

Formic acid (20 ml.) was added dropwise to acetic anhydride (40 ml.) at 0°-5° C. in the course of 15 minutes with stirring. After stirring was continued at the same temperature for 10 minutes and then at 45°-50° C. for 15 minutes, the mixture was cooled down to 0°-5° C. To this cooled mixture was added dropwise a solution of 3-(N-hydroxyamino)propylphosphonic acid (32.8 g.) in formic acid (60 ml.) at the same temperature in the course of 20 minutes, stirred for additional 45 minutes at ambient temperature, and then the resultant mixture was concentrated under reduced pressure. The residue was dissolved in ethanol (300 ml.), treated with activated charcoal (6 g.) and then filtered. The filtrate was diluted with ethanol (200 ml.) and treated with 28% aqueous ammonia (28 ml.) with stirring under ice-cooling to give an oily precipitate. The precipitate was separated by decantation and dissolved in water (120 ml.). The aqueous solution was treated with activated charcoal (4 g.), and filtered. To the aqueous filtrate was added ethanol (800 ml.) at 80° C. and allowed to stand overnight at ambient temperature to give crystalline monoammonium salt of 3-(N-formyl-N-hydroxyamino)propylphosphonic acid (30.55 g.), mp 158°-160.5° C. (dec.) The same monoammonium salt (4.35 g.) was recovered additionally from the mother liquor, by concentrating it to about 100 ml under reduced pressure mixing with ethanol (300 ml.) and allowing to stand at ambient temperature for 2 hours.

Herkunft & Nachweise