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:
May. 31, 1977
Filed:
Apr. 27, 1976
Christian Frey, Muttenz, CH;
Peter Moser, Binningen, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
A process for the manufacture of dyes of the formula ##STR1## WHEREIN EACH OF R.sub.1 and R.sub.2 represents a methyl or ethyl radical, n is 1 or 2, X.sup.- is the charge equivalent of an anion and B represents a divalent radical which completes the ring a to form a pyridinium or quinolinium ring which is unsubstituted or substituted by chlorine or methyl, and the ring b is unsubstituted or substituted by low molecular alkyl or alkoxy or by halogen, which process comprises treating a compound of the formula ##STR2## WHEREIN R.sub.1, n, X.sup.-, B, a and b are as defined in formula (1) and m is 1 or 2, in aqueous medium at a pH of 12 or above, with dimethyl or diethyl sulphate, with the proviso that if m=1, at least 2 equivalents of dimethyl or diethyl sulphate are used.