Novel resolution process for racemic spiro-hydantoins
US4952694A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1988 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Jul 27, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D491/10
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A novel three-step process for resolving a racemic spiro-hydantoin compound into its optical antipodes is disclosed, which involves (1) reacting said racemic compound with an optically-active asymmetric isocyanate of the formula RNCO, wherein R is (S)- or (R)-1-phenylethyl or (S) or (R)-1-(1-naphthyl)ethyl, to form the corresponding diastereomeric uredio compound; (2) separating the resulting diastereomeric mixture into its component parts, and (3) thereafter converting the separated ureido diastereomers obtained in step (b) to the corresponding asymmetric hydantoin compounds by treatment with an alkali metal lower alkoxide (C.sub.1 -C.sub.4), followed by acidification, whereupon the desired optical isomer is obtained. The final products so obtained, such as (4S)-(+)-6-fluoro-2,3-dihydro-spiro[4H-1-benzopyran-4,4'-imidazolidine]-2' , 5'-dione (sorbinil) and (5'S)-3'-chloro-5', 6', 7', 8'-tetra-hydro-spiro[imidazolidine-4,5'-quinoline]-2,5-dione, are known to be useful in preventing or alleviating certain chronic diabetic complications. The aforementioned diastereomeric uredio intermediates are novel compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.