Patent ID: 6762317
Filing Date: 2004-07-13
Classification: C07F

Abstract:
A method for producing N-(phosphonomethyl) glycine, a salt or ester thereof, the method comprising contacting formaldehyde, phosphorous acid and an amine, or a salt thereof, having the formula (III): wherein R4 and R5 are independently selected from the group consisting of H, â€”CH2PO(OR6)(OR7), hydrocarbyl, substituted hydrocarbyl, and heterocycle; and R6 and R7 are independently selected from the group consisting of H, hydrocarbyl, substituted hydrocarbyl, heterocycle, and a salt-forming cation; to produce a phosphonomethylation reaction product mixture containing an aminomethylphosphonic acid derivative, or a salt thereof, having the formula (II): wherein R1 and R2 are independently selected from the group consisting of H, hydrocarbyl, substituted hydrocarbyl, heterocycle, and a salt forming cation; and R4 and R5 are as defined above; contacting said aminomethylphosphonic acid substrate, or a salt thereof, having the formula (II), water and an oxidizing gas in the presence of a catalyst to form a reaction product mixture containing formylphosphonic acid or a salt thereof, and controlling the conditions under which said contacting is conducted so that (a) at least about 75% of the aminomethylphosphonic acid substrate is converted to formylphosphonic acid, or a salt thereof, (b) the molar ratio of formylphosphonic acid, or salt thereof to formic acid is at least about 2:1 in said reaction product mixture, and (c) no more than 50% of the formylphosphonic acid, or salt thereof formed in the reaction product mixture is consumed therein; contacting said formylphosphonic acid with glycine to produce a condensation reaction product mixture containing a condensed intermediate; and reducing said condensed intermediate to produce a reduction product mixture containing N-(phosphonomethyl) glycine, or a salt thereof.