acetamidomethylphosphonic acid

Conditions: temp:5.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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: with stirring during the course of 20 minutes The mixture was then stirred without cooling until room temperature It was then heated to reflux for 31/2 hours It was then cooled with stirring rising to 35° C After cooling the acetic acid was removed under reduced pressure with continuous warming to 95° C

Conditions: temp:5.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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: with stirring during the course of 20 minutes The mixture was then stirred without cooling until room temperature It was then heated to reflux for 31/2 hours It was then cooled with stirring rising to 35° C After cooling the acetic acid was removed under reduced pressure with continuous warming to 95° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 82 g of aqueous phosphorous acid and 32 g of trioxane are dissolved in 200 cc of acetonitrile. 5 cc of phosphorus trichloride are added to said solution. The resulting mixture is heated to boiling under reflux for about two hours. A highly viscous oil separates as a result of the reaction. Unreacted acetonitrile is distilled off. The residue is dissolved in a small amount of water. Addition of acetone precipitates therefrom a white crystalline product which is filtered off and dried at 60° C. in a water jet vacuum. About 100 g of N-acetylaminomethane phosphonic acid are obtained. By thin layer chromatographic investigation of the filtrate it was found that, in addition to phosphorous acid, the solution still contained some additional N-acetylaminomethane phosphonic acid and also another phosphonic acid which apparently is N-acetylimino-bis-methane phosphonic acid. The resulting mixture is heated under reflux for about two hours A highly viscous oil separates as a result of the reaction Unreacted acetonitrile is distilled off The residue is dissolved in a small amount of water Addition of acetone precipitates a white crystalline product which is filtered off dried at 60° C. in a water jet vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 82 g of aqueous phosphorous acid and 32 g of trioxane are dissolved in 200 cc of acetonitrile. 5 cc of phosphorus trichloride are added to said solution. The resulting mixture is heated to boiling under reflux for about two hours. A highly viscous oil separates as a result of the reaction. Unreacted acetonitrile is distilled off. The residue is dissolved in a small amount of water. Addition of acetone precipitates therefrom a white crystalline product which is filtered off and dried at 60° C. in a water jet vacuum. About 100 g of N-acetylaminomethane phosphonic acid are obtained. By thin layer chromatographic investigation of the filtrate it was found that, in addition to phosphorous acid, the solution still contained some additional N-acetylaminomethane phosphonic acid and also another phosphonic acid which apparently is N-acetylimino-bis-methane phosphonic acid. The resulting mixture is heated under reflux for about two hours A highly viscous oil separates as a result of the reaction Unreacted acetonitrile is distilled off The residue is dissolved in a small amount of water Addition of acetone precipitates a white crystalline product which is filtered off dried at 60° C. in a water jet vacuum

Conditions: temp:5.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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: with stirring during the course of 20 minutes The mixture was then stirred without cooling until room temperature It was then heated to reflux for 31/2 hours It was then cooled with stirring rising to 35° C After cooling the acetic acid was removed under reduced pressure with continuous warming to 95° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 82 g of aqueous phosphorous acid and 32 g of trioxane are dissolved in 200 cc of acetonitrile. 5 cc of phosphorus trichloride are added to said solution. The resulting mixture is heated to boiling under reflux for about two hours. A highly viscous oil separates as a result of the reaction. Unreacted acetonitrile is distilled off. The residue is dissolved in a small amount of water. Addition of acetone precipitates therefrom a white crystalline product which is filtered off and dried at 60° C. in a water jet vacuum. About 100 g of N-acetylaminomethane phosphonic acid are obtained. By thin layer chromatographic investigation of the filtrate it was found that, in addition to phosphorous acid, the solution still contained some additional N-acetylaminomethane phosphonic acid and also another phosphonic acid which apparently is N-acetylimino-bis-methane phosphonic acid. The resulting mixture is heated under reflux for about two hours A highly viscous oil separates as a result of the reaction Unreacted acetonitrile is distilled off The residue is dissolved in a small amount of water Addition of acetone precipitates a white crystalline product which is filtered off dried at 60° C. in a water jet vacuum