Water → P-((Acetylamino)methyl)phosphonic acid

Temperatur

5 °C

20 g (0.225 mol) of N-hydroxymethylacetamide were dissolved in 20 ml of acetic acid and cooled to 5° C. under a nitrogen atmosphere and with stirring. 12.4 g (0.113 mol) of diphosphorus trioxide (P2O3) were then added dropwise at 5° to 10° C. with stirring during the course of 20 minutes. The mixture was then stirred without cooling until room temperature was reached. It was then heated to reflux for 31/2 hours. It was then cooled. 2 g (0.11 mol) of water were then added dropwise with stirring, the temperature rising to 35° C. After cooling, the acetic acid was removed under reduced pressure and with continuous warming to 95° C. The crystalline residue was digested with ethanol. 26 g of crude acetylaminomethanephosphonic acid having a melting point of 171°-175° C. were obtained. After recrystallization from 88% strength aqueous acetic acid, 19 g (55% of theory) of acetylaminomethanephosphonic acid having a melting point of 186° to 90° C. were obtained. The CHNP elemental analysis of a sample gave:

1. stirringwith stirring during the course of 20 minutes
2. stirringThe mixture was then stirred
3. temperaturewithout cooling until room temperature
4. temperatureIt was then heated
5. temperatureto reflux for 31/2 hours
6. temperatureIt was then cooled
7. stirringwith stirring
8. customrising to 35° C
9. temperatureAfter cooling
10. customthe acetic acid was removed under reduced pressure
11. temperaturewith continuous warming to 95° C

ORD-Eintrag

ord-967f232b82e44e29ab1118de18402754

Quelldatensatz

uspto-grants-1992_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05155257