Patent ID: 7145034

Claim:
A process for preparing N-phosphonomethylglycine which comprises a) reacting a hexahydrotriazine derivative of the formula II in which X is CN, COOZ, CONR 1 R 2 or CH 2 OY, Y is H or a radical which is easily exchangeable for H; Z is H, an alkali metal, an alkaline earth metal, C 1 –C 18 -alkyl or aryl which is unsubstituted or substituted by C 1 –C 4 -alkyl, NO 2 or OC 1 –C 4 -alkyl; R 1 and R 2 may be identical or different and are H or C 1 –C 4 -alkyl, with a triacyl phosphite of the formula III P(OCOR 3 ) 3 (III) in which the radicals R 3 , which may be identical or different, are C 1 –C 18 -alkyl or aryl which is unsubstituted or substituted by C 1 –C 4 -alkyl, NO 2 or OC 1 –C 4 -alkyl in an organic solvent, b) extracting the resulting reaction mixture with water or an aqueous solution of an acid or an aqueous solution of a base, c) separating the phases and d) hydrolyzing the product contained in the aqueous phase.