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:
Oct. 21, 1997
Filed:
Nov. 13, 1995
Applicant:
Inventors:
Ian Hodgkinson, Huddersfield, GB;
John Heathcote Atherton, Huddersfield, GB;
Assignee:
Zeneca Limited, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07F / ;
U.S. Cl.
CPC ...
562 17 ;
Abstract
A process whereby N-phosphonomethylglycine (glyphosate) or its salts is manufactured by: 1) forming N-phosphonomethylglycinonitrile by reacting aminomethylphosphonic acid, an alkali metal cyanide and formaldehyde in aqueous solution at a pH in the range from 10 to 13 (and preferably from 11 to 11.5) whilst adding mineral acid at a rate sufficient to maintain the pH within the desired range, and thereafter 2) hydrolysing the N-phosphonomethylglycinonitrile product of Stage (1) to form a salt of N-phosphonomethylglycine and optionally 3) neutralising the salt of N-phosphonomethylglycine to form N-phosphonomethylglycine