Ethanolamine → N-(2-hydroxyethyl)aminomethylphosphonic acid

Temperature

80 °C

Dimethylphosphite (36 g, 0.3227 mole) was added dropwise over a period of 1 hour to a stirring solution of paraformaldehyde (9.8 g, 0.32 mole) and ethanolamine (20 g, 0.32 mole) below 20° C. under nitrogen. The solution was heated to 80° C. for 1 hour and then cooled to room temperature. The solution was extracted with 350 ml of benzene as described in the paper. The benzene solution was then passed through a column containing 1 kg of alumina and the column was eluted with 1 liter of benzene. The benzene solution was concentrated under vacuum to dryness and 250 mL of Conc. HCl was added. The solution was heated to 110° C. for 6 hours. Analysis of the reaction mixture by 31P-NMR showed 0% yield of N-(2-hydroxyethyl)aminomethylphosphonic acid. This Example demonstrates that contrary to what is disclosed in the Barsukov et al reference, the process taught in the Barsukov et al reference produces no N-(2-hydroxyethyl)aminomethylphosphonic acid.

1. temperaturecooled to room temperature
2. extractionThe solution was extracted with 350 ml of benzene
3. additioncontaining 1 kg of alumina
4. washthe column was eluted with 1 liter of benzene
5. concentrationThe benzene solution was concentrated under vacuum to dryness and 250 mL of Conc. HCl
6. additionwas added
7. temperatureThe solution was heated to 110° C. for 6 hours

ORD record

ord-819003f3da9d4065bacd02cf829b2545

Source dataset

uspto-grants-1997_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05602276