| 摘要 |
<p>The present invention relates to an energy and effluent saving process for the production of N-phosphonomethyliminodiacetic acid (PMIDA), an intermediate in the preparation of glyphosate. An alkali metal salt of iminodiacetic acid is reacted with phosphorous acid and a strong mineral acid, or a source thereof to form iminodiacetic phosphite and the alkali metal salt of the strong mineral acid. After removal of the latter salt, the iminodiacetic phosphite is converted to PMIDA by reaction with formaldehyde. PMIDA is recovered and the solution remaining can be recycled in the process.</p> |
