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US 4,065,491 AGranted
Process for the preparation of N-phosphonomethyl-glycine
AssigneeChinoin Gyogyszer es Vegyeszeti Termekek Gyara Rt.
InventorsTodor Pfliegel, Jeno Seres, Antal Gajary, Klara Daroczy nee Csuka, Lajos T. Nagy
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Abstract
The invention relates to a new and improved method for the preparation of N-phosphonomethyl-glycine, a potent pre-emergence herbicide. According to the invention glycine, formaldehyde and a dialkyl phosphite are condensed in an aqueous alkaline medium to form a N-phosphonomethyl-glycine dialkyl ester, and the diester is hydrolyzed with a mineral acid.
Claims2
A process for the preparation of N-phosphonomethyl-glycine comprising the steps of:
- a. reacting formaldehyde and glycine in an aqueous alkali-metal hydroxide medium in substantially equimolar quantities at a temperature of -5.degree. to +15.degree. C;
- b. adding to the reaction system of step (a) an amount of dimethyl or diethyl phosphite substantially equimolar to the glycine and formaldehyde;
- c. heating the reaction system of step (b) to a temperature of 50.degree. to 100.degree. C to form N-phosphonomethyl-glycine dimethyl or diethylester;
- and
- d. hydrolyzing the diester formed in step (c) by adding to the reaction system thereof at a temperature between 50.degree. and 100.degree. C a mineral acid selected from the group which consists of hydrochloric acid, sulfuric acid and phosphoric acid, thereby producing N-phosphonomethyl-glycine.
2 more elements
Dependencies are inferred from the claim text.