Process for the preparation of basic oxazine dyestuffs
US4362873A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 24, 1981 |
| Grant date | Dec 7, 1982 |
| Priority date | — |
| Expiry date | Mar 24, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B19/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of dyestuffs of the formula: ##STR1## in which R.sub.1 represents hydrogen, alkyl, alkenyl or aralkyl, R.sub.2 represents alkyl, alkenyl, cycloalkyl, aryl or aralkyl, R.sub.3 represents hydrogen, alkyl or alkoxy, R.sub.4 represents hydrogen, alkyl, aryl or aralkyl, R.sub.5 represents hydrogen or alkyl, R.sub.6 represents hydrogen, alkyl or alkoxy, R.sub.7 represents hydrogen or alkyl or forms with R.sub.6 a condensed benzene ring, and X.crclbar. represents an anion, which process comprises reacting a nitroso compound of formula (II) with an aminophenol of formula (III) or a nitroso compound of formula (IV) with a compound of formula (V): ##STR2## in which R.sub.1 to R.sub.7 have the same meanings as above, R'.sub.3, R'.sub.6 and R'.sub.7 each represents H or alkyl, R.sub.8 is a possibly substituted alkyl radical, and R.sub.9 is an alkoxy radical or a possibly substituted amino group. The reaction is effected in the presence of an anhydride such as acetic anhydride and the dyestuffs may be prepared without heating with excellent yields.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.