Preparation of phenylazonaphthalenes
US5770708A · kind A · utility
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4References
4Claims
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Key dates
| Filing date | May 27, 1997 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | May 27, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B69/045
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for preparing aqueous preparations of azo dyes of the formula ##STR1## where R is hydrogen or C.sub.1 -C.sub.4 -alkyl and PA1 Kat.sym. is the equivalent of a cation which derives from a tertiary amine of the ethanolamine or propanolamine series, by diazotization of an aniline of the formula ##STR2## with neopentylglycol dinitrite in an aqueous medium and coupling of the resulting reaction mixture with .beta.-naphthol in the presence of a water-miscible diluent and of an amine comprises using an amine comprising a tertiary amine of the ethanolamine or propanolamine series.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.