Synthesis of chrome-complexed dye developers in the presence of weakly basic anion exchange resins
US3970616A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1973 |
| Grant date | Jul 20, 1976 |
| Priority date | — |
| Expiry date | Nov 21, 1993 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/18
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An improved method for preparing a compound of the formula: ##SPC1## Where each R can be hydrogen, an alkyl substituent, preferably having from 1-6 carbon atoms or an alkoxy substituent preferably having from 1-6 carbon atoms and each R.sup.1 is hydrogen or an alkyl or an alkanol group. R.sup.2 is an alkylene radical having from 1-6 carbon atoms and X represents the atoms to complete a cyclopentyl or cyclohexyl ring. Metal complexed dyes of the above formula are especially useful in the preparation of photographic image patterns. The improved feature of the method presented involves the preparation of compounds of formula 1 in the presence of weakly basic anion exchange resins to obtain high yields of especially high purity products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.