Intermediates in the preparation of chiral spirofluorenehydantoins
US5151544A · kind A · utility
1Cited by
10References
8Claims
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Key dates
| Filing date | May 25, 1990 |
| Grant date | Sep 29, 1992 |
| Priority date | — |
| Expiry date | May 25, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2603/18
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Disclosed is a process for the synthesis of enantiomerically pure R and S isomers of 2,7-difluoro-4-methoxyspiro[9H-fluorene-9,4-imidazolidene]-2',5'-dione from 2,7-difluoro-4-methoxyfluorenone. Intermediate amino acid esters and urea esters and their preparation are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.