Patents by Inventor David Rees

David Rees has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Preparation of N-phosphonomethylglycine
    Patent number: 3956370
    Abstract: A process of preparing the herbicide N-phosphonomethylglycine which comprises reacting an N-substituted glycine derivative of the formula: ##EQU1## wherein R.sup.1 is a hydrogen atom or an esterifying group, Ar is an aryl radical, and R.sup.2 and R.sup.3 each stand for a hydrogen atom or an aryl radical, with formaldehyde and phosphorous acid in an acidic aqueous medium to give an N-substituted N-phosphonomethylglycine derivative of the formula: ##EQU2## and thereafter reacting the said N-substituted N-phosphonomethylglycine with hydrobromic or hydriodic acid to remove the N-substituent, and recovering N-phosphonomethylglycine.
    Type: Grant
    Filed: July 2, 1973
    Date of Patent: May 11, 1976
    Assignee: Imperial Chemical Industries Limited
    Inventors: David Rees Parry, Clive Dudley Spencer Tomlin