Patent US4130714A successfully refreshed from Google Patents.
US4130714A
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US
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Hydantoin therapeutic agents
Assignee: Pfizer Inc
•
Filing: 1977-05-23
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Granted: 1978-12-19
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Expires: 1997-05-23
Abstract
Abstract Several novel dextrotatory spiro-hydantoin compounds have been obtained by resolving the corresponding dl-compounds which are initially synthesized by first condensing the appropriate carbonyl ring compound, such as the corresponding 4-chromanone or thiochroman-4-one, as the case may be, with potassium cyanide and ammonium carbonate. The resulting optically-active hydantoin derivatives, such as d-6-fluoro-spiro-[chroman-4,4'-imidazolidine]-2',5'-dione and d-6'-fluoro-spiro-[imidazolidine-4,4'-thiochroman]-2,5-dione, are particularly useful in preventing or alleviating chronic diabetic complications.
Inventors
- 👤 Reinhard Sarges
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:30
CPC Classifications
C; C07; C07D; C07D491/00; C07D491/02; C07D491/10; C07D311/00; C07D311/02; C07D311/04; C07D311/22; C07D495/00; C07D495/02; C07D495/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
33 words
A compound selected from the group consisting of the dextrorotatory isomers of asymmetric spiro-hydantoins of the formula: ##STR3## and the base salts thereof with pharmacologically acceptable cations, wherein Y is oxygen or sulfur.
Claim 2
Dependent Claim
33 words
A compound selected from the group consisting of the dextrorotatory isomers of asymmetric spiro-hydantoins of the formula: ##STR3## and the base salts thereof with pharmacologically acceptable cations, wherein Y is oxygen or sulfur.
Claim 3
Dependent Claim
11 words
A compound as claimed in claim 1 wherein Y is oxygen.
Claim 4
Dependent Claim
11 words
A compound as claimed in claim 1 wherein Y is sulfur.
Claim 5
Dependent Claim
1 words
d-6-Fluoro-spiro-[chroman-4,4'-imidazolidine]-2',5'-dione.
Claim 6
Dependent Claim
1 words
d-6-Fluoro-spiro-[chroman-4,4'-imidazolidine]-2',5'-dione.
Claim 7
Dependent Claim
1 words
d-6'-Fluoro-spiro[imidazolidine-4,4'-thiochroman]-2,5-dione.
Claim 8
Dependent Claim
1 words
d-6'-Fluoro-spiro[imidazolidine-4,4'-thiochroman]-2,5-dione.
References Cited (Backward Citations)
US2683718A
Cited
DE1135915B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |