Process for the manufacture of basic oxazine dyes
US4018763A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1975 |
| Grant date | Apr 19, 1977 |
| Priority date | — |
| Expiry date | Apr 14, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B19/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of basic oxazine dyes of the formula ##STR1## wherein R represents a low molecular alkoxy or alkyl group which is substituted or unsubstituted, R.sub.1 represents a low molecular alkyl group which is substituted or unsubstituted, R.sub.2 represents a low molecular alkyl group which is substituted or unsubstituted or an aryl radical, and each of R.sub.3 and R.sub.4 independently represents hydrogen or a low molecular alkyl radical which is substituted or unsubstituted, and R.sub.1 may be attached to R.sub.2 and R.sub.3 to R.sub.4 through a heteroatom, and wherein the ring a can carry further non-ionogenic substituents or a fused benzene ring, and X.sup.- represents an anion, which process comprises treating a compound of the formula ##STR2## wherein R.sub.1, R.sub.2 and a have the meanings previously assigned to them, with nitrous acid in a polar, water-miscible solvent and adding to the resultant nitrosation mixture, without isolating the nitroso compound, a diamine of the formula ##STR3## wherein R, R.sub.3 and R.sub.4 have the indicated meanings and each of R.sub.5 and R.sub.6 represents hydrogen or a low molecular alkyl group.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.