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:
Aug. 03, 1993
Filed:
Sep. 25, 1992
George E Heinsohn, Elkton, MD (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
N-acylaminomethylphosphonic acids having the formula RCO--NH--CH.sub.2 --P(.dbd.O)(OH).sub.2, where R is a non-interfering organic radical, are prepared by (A) combining a solution of a carboxamide, RCO--NH.sub.2, paraformaldehyde and phosphorous acid in an anhydrous solvent with a carboxylic acid anhydride, e.g., acetic anhydride, or (B) combining a solution of the carboxamide and paraformaldehyde in an anhydrous solvent with a solution of the carboxylic acid anhydrid and phosphorous acid in an anhydrous solvent, followed by heating the resulting solution to complete the reaction. The N-acylaminomethylphosphonic acids can be hydrolyzed to aminomethylphosphonic acid.