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. 22, 1983
Filed:
Nov. 06, 1981
Hans-Gerd Elinkmann, Frankfurt am Main, DE;
Emmerich Paszthory, Hofheim am Taunus, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Mixtures of isomers of benzoxanthene and benzothioxanthene dyestuffs of the formulae ##STR1## wherein X is oxygen or sulfur, R optionally substituted alkyl, acyl or arylsulfonyl, R.sub.1 and R.sub.2 are hydrogen or halogen, alkyl, aryl, acyl, acyloxy, carbalkoxy, alkoxy, nitro, alkylthio or alkylsulfonyl or they form together a condensed benzene ring, R.sub.3 and R.sub.4 are hydrogen or halogen, alkyl, alkoxy, aryl, carbalkoxy or nitrile, R.sub.5 and R.sub.6 are hydrogen or optionally substituted alkoxy, are obtained by condensing the corresponding benzoxanthene or benzothioxanthene-3,4-carboxylic acid anhydrides or esters with phenyl acetic acid anhydrides or esters in the presence of alkali at a temperature of about 150.degree. to 260.degree. C. and alkylating or acylating the so-obtained hydroxy intermediates without previous isolation thereof when condensation and alkylation or acylation are performed in a polar organic solvent.