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:
Mar. 02, 1993
Filed:
Jul. 30, 1992
Applicant:
Inventor:
Brian A Parker, Nashua, NH (US);
Assignee:
W. R. Grace & Co.-Conn., New York, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
558346 ; 5483001 ;
Abstract
A novel intermediate useful in the synthesis of ethylenediaminetriacetic acid (ED3A) or its salts. A salt of N,N'-ethylenediaminediacetic acid (ED2AH.sub.2) is condensed with formaldehyde to form a stable 5-membered ring intermediate. The addition of cyanide across this cyclic material forms ethylenediamine N,N'-diacetic acid-N'-cyanomethyl or salts thereof (mononitrile-diacid), which is a useful intermediate in the production of ED3A. The nitrile in aqueous solutions may be spontaneously cyclized to form 2-oxo-1,4-piperazinediacetic acid (3KP) or salts thereof. In the presence of excess base, salts of ED3A are formed in excellent yield and purity.