METHOD OF SYNTHESIS OF N-HYDROXYALKYLAMINOMETHYLPHOSPHONIC ACID, N-PHOSPHONOMETHYLAMINOCARBOXYLIC ACID AND N-PHOSPHONO-METHYLGLYCINE OR THEIR SALTS Russian patent published in 2000 - IPC

FIELD: organic chemistry and chemical technology, herbicides. SUBSTANCE: invention relates to methods of synthesis of N-hydroxyalkylaminomethylphosphonic acid of the formula (I) , N-phosphonomethylaminocarboxylic acid of the formula (II) , N-phosphonomethylglycine of the formula (III) or their salts. Compounds (I) are synthesized by interaction of alkanolamine of the formula H₂N-(CH₂)_n-OH where n = 2-6 with formaldehyde and dialkylphosphite in the presence of alcohol at 50-150 C followed by hydrolysis of formed reaction mass under acid or alkaline conditions. Compounds (II) are synthesized by catalytic oxidation of N-hydroxyalkyl- -aminomethylphosphonic acid or its salts with alkaline metal hydroxide in the presence of effective amount of Raney copper catalyst containing from 50 to 10 000 p.p.m. of element taken among the group consisting of chrome, titanium, niobium, tantal. N-Phosphonomethylglycine (III) is synthesized by interaction of ethanolamine, formaldehyde and dialkylphosphite in the presence of alcohol at 50-150 C followed by hydrolysis of formed reaction mixture under acid or alkaline conditions to yield the compound of the formula (I) that is subjected for catalytic oxidation. Synthesized compounds are highly effective herbicides and used in agriculture. EFFECT: improved method of synthesis. 26 cl, 3 tbl