反应详情

50 ml of acetic acid were cooled to 10° C. with stirring and under a nitrogen atmosphere. 11 g (0.1 mol) of diphosphorus trioxide (P2O3) were then added dropwise with further cooling, during the course of which the temperature fell to 0° to 5° C. 30.2 g (0.2 mol) of N-hydroxymethylbenzamide were then added in portions at 5°-10° C. during the course of 60 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. The mixture was then allowed to cool and 25 ml of acetone were added. It was then additionally stirred and filtered with suction. 31.5 g of benzoylaminomethanephosphonic acid having a melting point of 165° to 170° C. were obtained. A further 2 g were isolated from the mother liquor. Altogether, 33.5 g (78% of theory) were thus obtained.

1. customfell to 0° to 5° C
2. stirringThe mixture was then stirred
3. temperatureIt was then heated
4. temperatureto reflux for 31/2 hours
5. temperatureIt was then cooled
6. stirringwith stirring
7. customrising to 35° C
8. temperatureto cool
9. stirringIt was then additionally stirred
10. filtrationfiltered with suction