Glycine → Glyphosate

Participants

Reaction Steps

A mixture of about 50 parts of glycine, 92 parts of chloromethylphosphonic acid, 150 part of 50% aqueous sodium hydroxide and 100 parts water was introduced into a suitable reaction vessel and maintained at reflux temperature while an additional 50 parts of 50% aqueous sodium hydroxide was added. The pH of the reaction mixture was maintained between 10 and 12 by the rate of addition of the sodium hydroxide. After all of the caustic solution had been added, the reaction mixture was refluxed for an additional 20 hours, cooled to room temperature and filtered. About 160 ml. of concentrated hydrochloric acid were then added and the mixture filtered to provide a clear solution which slowly deposited N-phosphonomethylglycine. This material had a melting point of 230° C. with decomposition.

Provenance & Evidence