Pyridazine derivatives, manufacturing method and related composition
US6395896B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2000 |
| Grant date | May 28, 2002 |
| Priority date | — |
| Expiry date | Dec 15, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61Q5/02
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Ultraviolet absorbents and photostabilizers have an excellent absorption ability in a wide range of ultraviolet rays, and also have high stability and high safety. The ultraviolet absorbent and photostabilizer include a pyridazine derivative of the formula (1): or salts thereof. Also, described are methods for manufacturing said pyridazine derivative and/or this salts thereof comprising the process of reacting at least 10 wt % of 4,5-dichloro-3-hydroxypyridazine or 4,5-dibromo-3-hydroxypyridazine or mixtures thereof with at least 20 vol % of morpholine in reaction solution at 70° C. or higher. The ultraviolet absorbents photostabilizers include said pyridazine derivative and/or salts thereof as effective ingredient. An ultraviolet ray absorption composition and an external preparation for skin are also included.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.