Water → Glyphosate

Participants

Reaction Conditions

Reaction Steps

To a 100 ml Monel autoclave were charged 2.08 g (11.4 mmol) of N-ethyl-N-(2-hydroxyethyl)-aminomethylphosphonic acid and 3.63 g (91 mmol) of dry, powdered NaOH. The two powders were intimately mixed. To this mixture 1 ml of water was added and mixed until the dampness was evenly distributed through the mass. The reaction vessel was then flushed with N2, sealed and heated to 315° C. for two and a half hours. When the vessel had reached 315° C. an internal pressure of 2.2×106N/M2 had been established. By the end of the heating period the pressure had risen to 3.5×106N/M2. The excess pressure generated to this point was released and an additional 9 ml of H2O were introduced. The reaction temperature was adjusted to 300° C. which produced an internal pressure of 4.3×106N/M2. After five hours of heating at 300° C., the internal pressure had reached 4.6× 106N/M2. The reaction was allowed to cool to room temperature at which point the residual pressure was released. The reaction mixture was diluted with water and neutralized with 91 mmol of HCl. The solution was stripped to dryness. The residue was taken up in conc. HCl and the precipitated NaCl was filtered off. The filtrate was concentrated and purified by ion exchange chromatography to yield 0.38 g (20%) of N-phosphonomethylglycine based on the original substrate.

Provenance & Evidence