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:
Dec. 12, 1991
Brian A Parker, Nashua, NH (US);
W. R. Grace & Co.-Conn., New York, NY (US);
Abstract
A novel intermediate useful in the synthesis of ethylenediaminetriacetic acid (ED3A) or its salts. N,N'-ethylenediaminediacetic acid (ED2AH.sub.2) or a salt containing up to one equivalent of base cation 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 or 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.