Hydrochloric Acid → ethyl N-carbobenzoxy-N-(dichlorophosphonomethyl)glycinate

Participants

Reaction Steps

Ethyl N-phosphonomethylglycine (9.85 g., 0.05 mole) and benzyl chloroformate (9.4 g., 0.05 mole) were dissolved in 50 ml. of water and sodium carbonate (7.95 g., 0.075 mole) was added over a 1/2 hour period. The solution was stirred until all of the benzyl chloroformate had reacted. Concentrated hydrochloric acid (12.5 ml) was then added. Upon standing ethyl N-carbobenzoxy-N-phosphonomethylglycinate separated as an oil. The oil was then dried in a vacuum dessicator over phosphorus pentoxide at 0.55 torr. A 4 g. sample of the oil was dissolved in oxalyl chloride (20 ml) and stirred until gas evolution ceased. The mixture was concentrated in vacuo to yield ethyl N-carbobenzoxy-N-(dichlorophosphonomethyl)glycinate as a colorless oil. The oil is treated with an excess of oxalyl chloride to convert it to ethyl N-carbobenzoxy-N-phosphonomethylglycine dichloride which is then reacted with the appropriate thiol of the formula

Provenance & Evidence