| 摘要 |
PCT No. PCT/EP97/03955 Sec. 371 Date Dec. 7, 1998 Sec. 102(e) Date Dec. 7, 1998 PCT Filed Jul. 22, 1997 PCT Pub. No. WO98/03517 PCT Pub. Date Jan. 29, 1998To prepare N-phosphonomethyl glycine, a) aminomethylphosphonic acid or one of its salts in water, if necessary or desirable with the addition of lyes, is reacted with an alkali carbonate and/or alkali hydrogencarbonate or with carbon dioxide and a lye, b) the resulting alkali salt of N-phosphonomethylcarbamic acid is subsequently hydroxymethylated with formaldehyde, c) the salts, resulting from b), of N-hydroxymethyl-N-phosphonomethyl-carbamic acid, if necessary or desirable with addition of a lye, are reacted with hydrocyanic acid and/or a cyanide and d) the N-carboxy-N-phosphonomethylglyconitrile salts thus obtained are treated with acids and converted by means of hydrolysis and decarboxylation into N-phosphonomethyl glycine. In this way, it is possible to obtain excellent yields of high-purity N-phosphonomethyl glycine.
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