Process for preparation of 4-mercapto-1-naphthol compounds
US5693846A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1996 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Aug 1, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/30552
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparation of 4-mercapto-1-naphthol compounds which comprises the steps of: PA1 (i) obtaining a 4-heterocyclylthio-1-naphthol compound by reacting a 1-naphthol compound with a heterocyclylsulfur chloride or by reacting a 4-iodo-1-naphthol compound with an alkali metal or ammonium salt of a mercaptoheterocyclic compound, PA1 (ii) hydrolyzing the resulting 4-heterocyclylthio-1-naphthol compound in the presence of a base to form a reaction product, and PA1 (iii) acidifying said reaction product. The resulting compounds are useful as intermediates in the synthesis of bleach accelerator releasing couplers for use in silver halide color photographic materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.