Water → Benzoylaminomethanephosphonic acid

Participants

Reaction Conditions

Reaction Steps

30.2 g (0.2 mol) of N-hydroxymethylbenzamide were dissolved in 50 ml of tetrahydrofuran and cooled to 5° C. with stirring, then a solution of 11 g (0.1 mol) of diphosphorus trioxide (P2O3) in 20 ml of tetrahydrofuran was added dropwise at 5°-15° C. during the course of 30 minutes under a nitrogen atmosphere. The reaction solution obtained was then cooled to 2° C. for 10 minutes. Cooling was then omitted, the internal temperature rising to 35° C. The mixture was then heated to reflux for 2 hours; a clear solution was not formed in this case. It was then cooled. 4.5 g (0.25 mol) of water were then added dropwise at 30°-35° C. with cooling. The mixture was then heated to reflux for 1 hour, then cooled and additionally stirred and finally filtered with suction. 25 g of benzoylaminomethanephosphonic acid having a melting point of 175° to 178° C. were obtained. A further 5.5 g were isolated from the mother liquor. Altogether, 30.5 g (71% of theory) of product were thus obtained.

Provenance & Evidence