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, 1999
Filed:
Oct. 16, 1997
Applicant:
Inventors:
Gert Nagl, Niederdorfelden, DE;
Wolfgang Bauer, Maintal, DE;
Manfred Urban, Wiesbaden, DE;
Dieter Schnaitmann, Eppstein, DE;
Assignee:
Clariant GmbH, Frankfurt, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
544 99 ;
Abstract
The present invention relates to a process for the preparation of dioxazine derivatives of the formula I ##STR1## in which R.sup.1 is hydrogen or (C.sub.1 -C.sub.8)-alkyl, by ring closure of a compound of the formula II ##STR2## in the presence of a ring-closure agent, wherein the ring-closure agent used is an N-hetarene N-oxide. The compounds of the formula I are used for producing valuable dyes and pigments.