The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 1976
Filed:
Jul. 02, 1973
David Rees Parry, Wokingham, EN;
Clive Dudley Tomlin, Crowthorne, EN;
Imperial Chemical Industries Limited, London, EN;
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.