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. 14, 1989
Filed:
Feb. 27, 1987
Applicant:
Inventor:
Udo Eckstein, Cologne, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
546 94 ; 544 73 ; 544 74 ; 544 89 ; 544101 ; 544105 ; 544283 ; 544344 ; 544353 ; 546104 ; 546165 ; 546166 ; 546167 ; 548217 ; 548220 ; 548327 ; 548328 ; 548439 ; 548456 ;
Abstract
Chromogenic phthalides of the general formula ##STR1## wherein R.sub.1 and R.sub.2 independently of one another denote hydrogen, alkyl, alkenyl, aralkyl, cycloalkyl or aryl or are linked to the ring A or B respectively in the o-position to the nitrogen and then represent the remaining members of a partially or fully hydrogenated heterocyclic 5-membered or 6-membered ring which can contain a further heteroatom from the series O, S, N--R.sub.1 or N--R.sub.2,