Industrial process for the production of diphenyl sulfone compounds
US6590126B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2001 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | Sep 21, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C315/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing compounds of general formula (II) useful as the developer for leuco dyes to be used in thermosensible papers, which is excellent in productivity, economical efficiency and safety and permits the production of the compounds from constantly available raw materials. This process is improved in productivity, economical efficiency and safety as compared with those of the prior art both by shortening the production time by the use of, e.g., an alkyl iodide, RI, which is more reactive than alkyl bromides which have been used in the prior art, and by attaining the complete recovery and reuse of iodine by incorporating into the process the iodine recovery step of recovering iodine from the manufacturing wastewater and reacting this iodine with an alcohol to thereby self-produce an alkyl iodide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.