Patent ID: 11312627

Abstract:
The present invention is generally directed to improved processes for the preparation of various phosphorus oxides and phosphoric acid. Phosphorus oxides prepared in accordance with the present invention include phosphorus (III) oxides (e.g., tetraphosphorus hexaoxide (P4O6)). Phosphorus (III) oxides such as P4O6 are useful products and are also useful as precursors in preparation of other products, including phosphorous acid (H3PO3) and other phosphorus-containing chemicals. Certain aspects of this invention are also directed to using various byproducts formed during P4O6 production as precursors for the formation of phosphoric acid (H3PO4) and P2O5. In particular, the present invention is directed to improved processes for the preparation of phosphorus (III) oxides (e.g., P4O6) suitable for use in the preparation of phospho-herbicides such N-(phosphonomethyl)glycine (glyphosate) and precursors thereof (e.g., N-(phosphonomethyl)iminodiacetic acid (PMIDA)). The present invention is thus further directed to preparation of these compounds.