3,4,5,6-Tetrahydrophthalic anhydride → Glyphosate

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Reaction Steps

The disodium salt of N-phosphonomethylglycine is prepared as described in Example III. The salt solution is stirred while 8.5 grams of 3,4,5,6-tetrahydrophthalic anhydride is added, along with sodium hydroxide to maintain the pH above 8. The reaction mixture is rotated overnight, after which a further 1.0 gram of anhydride is added and the reaction mixture stirred to completion. The mixture is filtered to yield a pink solution containing some disodium tetrahydrophthalate as a by-product. The reaction product is identified by nmr as the trisodium salt of N-carboxymethyl-N-phosphonomethyl-3,4,5,6-tetrahydrophthalamic acid. ##STR6##

Provenance & Evidence