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. 19, 1997
Filed:
Dec. 08, 1994
Michael Bamber, Water Orton, GB;
Gary Woodward, Kidderminster, GB;
Albright & Wilson Limited, West Midlands, GB;
Abstract
A method for the production of azacycloalkane-2,2-diphosphonic acids of general formula; ##STR1## where n is a whole number of from 2 to 16, Y is H, an alkyl or alkenyl, a substituted alkyl, or an aryl, such that the group 'Y' remains unchanged during the reaction, by reaction of a lactam with a phosphorus trihalide in the presence of phosphorous acid and/or water, in which the reaction mixture also includes an organic amine and/or or an organic amine salt, said reaction being followed by hydrolysis of the reaction mixture and purification of the reaction product to obtain the diphosphonic acid. The method is exemplified by the preparation of azacycloheptane-2,2-diphosphonic acid, and azacyclononane-2,2-diphosphonic acid.