Method for preparing spiro(indoline)-type photochromic compounds
US4634767A · kind A · utility
26Cited by
7References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1985 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Sep 3, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/685
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Spiro(indoline)-type photochromic compounds are prepared by admixing a solution of the Fischer's Base reactant in non-polar solvent with a mixture of the pyran- or oxazine-forming reactant, e.g., 5-nitroso-6-hydroxy quinoline, in polar solvent and heating the resulting reaction medium at temperatures sufficient to form the corresponding spiro(indoline)-type compound while simultaneously removing co-product water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.