# US 5,703,273 A · Process for preparing N-phosphonomethylamino carboxylic acids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,273 A - Document ID: US5703273A - Status: Granted - Kind: A - Application number: 08/674,211 - Filed: 1996-07-01 - Granted: 1997-12-30 - Earliest claimed: 1994-07-01 - Assignees: Monsanto Company - Inventors: Michael K. Stern; Brian K. Cheng; Jerry R. Ebner; Dennis P. Riley - Web page: https://patentgrep.com/patent/US5703273A ## CPC - C07F 9/3813: {N-Phosphonomethylglycine; Salts or complexes thereof} - C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22) ## Abstract A process for preparing N-hydroxyalkylaminomethyl-phosphonic acid or salts thereof which comprises contacting an alkanolamine, formaldehyde and a trialkyl phosphite under suitable reaction conditions to produce a reaction mixture, and hydrolyzing the reaction mixture under neutral, acidic or basic conditions. In one embodiment, the N-hydroxyalkylaminomethylphosphonic acid or salts thereof is catalytically oxidized to produce an N-phosphonomethylaminocarboxylic acid or salts thereof. ## Claims ### Claim 1 A process for preparing N-hydroxyalkylaminomethylphosphonic acid represented by the formula ##STR6## or salts thereof comprising: (a) contacting an alkanolamine represented by the formula ##STR7## wherein n is 2 to 6, formaldehyde and a trialkyl phosphite under suitable conditions of time and temperature to produce a reaction mixture wherein the molar ratio of alkanolamine to phosphite is about 1:1 to about 15:1, and (b) hydrolyzing said reaction mixture under neutral, acidic or basic conditions. ### Claim 2 (depends on 1) The process of claim 1 wherein said reaction of (a) is conducted in the presence of an alcohol. ### Claim 3 (depends on 1) The process of claim 1 wherein the molar ratio of formaldehyde to phosphite is 1:1 to about 5:1. ### Claim 4 (depends on 3) The process of claim 3 wherein the alkyl groups of said trialkyl phosphite have 3 to 4 carbon atoms. ### Claim 5 (depends on 1) The process of claim 1 wherein said trialkyl phosphite is triisopropyl phosphite. ### Claim 6 (depends on 1) The process of claim 1 wherein the molar ratio of alkanolamine to phosphite is about 1.2:1 to about 8:1 and the number of carbon atoms in the alkyl group of said trialkyl phosphite is 2 to 6. ### Claim 7 (depends on 6) The process of claim 6 wherein said trialkyl phosphite is triisopropyl phosphite. ### Claim 8 (depends on 1) The process of claim 1 wherein the molar ratio of alkanolamine to phosphite is about 1:1 to about 10:1 and the number of carbon atoms in the alkyl group of said trialkyl phosphite is 1 or greater than 6. ### Claim 9 (depends on 1) The process of claim 1 wherein the hydrolysis is conducted under basic conditions. ### Claim 10 (depends on 9) The process of claim 9 wherein said hydrolysis is conducted in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide. ### Claim 11 (depends on 9) The process of claim 9 wherein alcohol formed during said hydrolysis is removed during said hydrolysis. ### Claim 12 (depends on 1) The process of claim 1 wherein n is 2. ### Claim 13 (depends on 1) The process of claim 1 further comprising: (c) catalytically oxidizing said N-hydroxyalkylaminomethylphosphonic acid or salts thereof to produce an N-phosphonomethylaminocarboxylic acid represented by the formula ##STR8## or salts thereof. ### Claim 14 (depends on 12) The process of claim 12 wherein the oxidation is conducted by contacting said N-hydroxyalkylaminomethylphosphonic acid or salts thereof with an alkali metal hydroxide in the presence of an effective amount of a Raney copper catalyst containing from about 50 to about 10,000 parts per million of an element selected from the group consisting of chromium, titanium, niobium, tantalum, zirconium, vanadium, molybdenum, manganese, tungsten, cobalt, nickel and mixtures thereof. ### Claim 15 (depends on 13) The process of claim 13 wherein the oxidation is conducted in the presence of an effective amount of a carbon supported mixed metal catalyst. ### Claim 16 (depends on 15) The process of claim 15 wherein said catalyst is a carbon supported mixture of Cu and Pt or Pd. ### Claim 17 (depends on 1) The process of claim 1 wherein said temperature of the reaction of (a) is about 50.degree. C. to about 150.degree. C. ### Claim 18 A process for preparing N-phosphonomethylglycine or salts thereof comprising: (a) contacting ethanolamine, formaldehyde and a trialkyl phosphite under suitable reaction conditions of time and temperature to produce a reaction mixture wherein the molar ratio of ethanolamine to phosphite is about 1:1 to about 15:1, (b) hydrolyzing said reaction mixture under neutral, acidic or basic conditions to produce N-hydroxyethylaminomethylphosphonic acid or salts thereof, and (c) catalytically oxidizing said N-hydroxyethylaminomethylphosphonic acid or salts thereof. ### Claim 19 (depends on 18) The process of claim 18 wherein said trialkyl phosphite is triisopropyl phosphite. ### Claim 20 (depends on 18) The process of claim 18 wherein the oxidation is conducted by contacting said N-hydroxyalkylaminomethylphosphonic acid or salts thereof with an alkali metal hydroxide in the presence of an effective amount of a Raney copper catalyst containing from about 50 to about 10,000 parts per million of an element selected from the group consisting of chromium, titanium, niobium, tantalum, zirconium, vanadium, molybdenum, manganese, tungsten, cobalt, nickel and mixtures thereof. ### Claim 21 (depends on 18) The process of claim 18 wherein the oxidation is conducted in the presence of an effective amount of a carbon supported mixed metal catalyst. ### Claim 22 (depends on 18) The process of claim 18 wherein the hydrolysis is conducted under basic conditions. ### Claim 23 (depends on 22) The process of claim 22 wherein the hydrolysis is conducted in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide. ### Claim 24 (depends on 22) The process of claim 22 wherein alcohol formed during said hydrolysis is removed during said hydrolysis. ### Claim 25 (depends on 18) The process of claim 18 wherein said reaction of (a) is conducted in the presence of an alcohol. ### Claim 26 (depends on 18) The process of claim 18 wherein the molar ratio of ethanolamine to phosphite is about 1.2:1 to about 8:1 and the number of carbon atoms is the alkyl group of said trialkyl phosphite is 2 to 6. ### Claim 27 (depends on 26) The process of claim 26 wherein said trialkyl phosphite is triisopropyl phosphite. ### Claim 28 (depends on 18) The process of claim 18 wherein the molar ratio of alkanolamine to phosphite is about 1:1 to about 10:1 and the number of carbon atoms in the alkyl group of said trialkyl phosphite is 1 or greater than 6. ### Claim 29 (depends on 18) The process of claim 18 wherein the molar ratio of formaldehyde to phosphite is 1:1 to about 5:1. ### Claim 30 A process for preparing N-hydroxyalkylaminomethylphosphonic acid represented by the formula ##STR9## or salts thereof comprising: (a) contacting an alkanolamine represented by the formula H.sub.2 N.paren open-st.CH.sub.2 .paren close-st..sub.n OH wherein n is 2 to 6, formaldehyde and a trialkyl phosphite in the presence of an alcohol represented by the formula R(OH).sub.m wherein R is an alkyl group having 1 to about 18 carbon atoms and m is 1 to 3, under suitable conditions of time and temperature to produce a reaction mixture wherein the molar ratio of alkanolamine to phosphite is about 1:1 to about 5:1, and (b) hydrolyzing the reaction mixture under neutral, acidic or basic conditions. ### Claim 31 (depends on 30) The process of claim 30 wherein said trialkyl phosphite is triisopropyl phosphite. ### Claim 32 (depends on 30) The process of claim 30 wherein n is 2. ### Claim 33 (depends on 30) The process of claim 30 wherein the molar ratio of alkanolamine to phosphite is 1:1 to about 2:1. ### Claim 34 (depends on 30) The process of claim 30 further comprising: (c) catalytically oxidizing said N-hydroxyalkylaminomethylphosphonic acid or salts thereof to produce an N-phosphonomethylaminocarboxylic acid represented by the formula ##STR10## or salts thereof. ### Claim 35 (depends on 34) The process of claim 34 wherein the oxidation is conducted by contacting said N-hydroxyalkylaminomethylphosphonic acid or salts thereof with an alkali metal hydroxide in the presence of an effective amount of a Raney copper catalyst containing from about 50 to about 10,000 parts per million of an element selected from the group consisting of chromium, titanium, niobium, tantalum, zirconium, vanadium, molybdenum, manganese, tungsten, cobalt, nickel and mixtures thereof. ### Claim 36 (depends on 34) The process of claim 34 wherein the oxidation is conducted in the presence of an effective amount of a carbon supported mixed metal catalyst. ### Claim 37 (depends on 30) The process of claim 30 wherein the hydrolysis is conducted under basic conditions. ### Claim 38 (depends on 37) The process of claim 37 wherein alcohol formed during said hydrolysis is removed during said hydrolysis. ### Claim 39 (depends on 4) The process of claim 4 wherein the molar ratio of alkanolamine to phosphite is about 1.5:1 to about 2.5:1. ### Claim 40 (depends on 39) The process of claim 39 wherein said trialkyl phosphite is triisopropyl phosphite. ### Claim 41 (depends on 39) The process of claim 39 where in the molar ratio of formaldehyde to phosphite is 1:1 to about 2:1.