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:
Jan. 20, 1998
Filed:
Nov. 02, 1995
Applicant:
Inventors:
Carl Christoph Mollenkopf, Frankfurt am Main, DE;
Ernst Ingo Leupold, Neu-Anspach, DE;
Gunter Roscher, Kelkheim, DE;
Assignee:
Hoechst AG, Frankfurt, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07F / ;
U.S. Cl.
CPC ...
562878 ;
Abstract
Process for preparing alkanephosphonic anhydrides of the formula (I) ##STR1## where R is straight-chain or branched unsubstituted C.sub.1 -C.sub.6 -alkyl and n.gtoreq.3, which comprises pyrolytically eliminating water from an alkanephosphonic acid of the formula (II) or a pyroalkanephosphonic acid of the formula (III) ##STR2## where R is straight-chain or branched C.sub.1 -C.sub.6 -alkyl, without addition of solvent and removing the water from the reaction mixture by means of an inert gas stream.