Patent US4438272A successfully refreshed from Google Patents.
US4438272A
Expired / Lapsed
US
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Spiro-(fluoren-9,4'-imidazolidine)-2',5'-diones
Assignee: Alcon Research LLC
•
Filing: 1982-04-15
•
Granted: 1984-03-20
•
Expires: 2002-04-15
Abstract
Abstract Tetracyclic spiro-hydantoin derivatives useful in the treatment of complications arising from diabetes mellitus.
Inventors
- 👤 Billie M. York, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:00
CPC Classifications
C; C07; C07D; C07D235/00; C07D235/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
25 words
A spiro-(fluoren-9,4'-imidazolidine)-2', 5'-dione or pharmaceutically acceptable salt thereof having the formula ##STR10## Where x=hydrogen, fluoro, methylthio, methylsulfinyl, and methylsulfonyl, and y=fluoro, methylthio, melthylsulfinyl and methylsulfonyl.
Claim 2
Dependent Claim
25 words
A spiro-(fluoren-9,4'-imidazolidine)-2', 5'-dione or pharmaceutically acceptable salt thereof having the formula ##STR10## Where x=hydrogen, fluoro, methylthio, methylsulfinyl, and methylsulfonyl, and y=fluoro, methylthio, melthylsulfinyl and methylsulfonyl.
Claim 3
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR11##
Claim 4
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR12##
Claim 5
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR13##
Claim 6
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR14##
Claim 7
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR15##
Claim 8
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR16##
Claim 9
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR17##
Claim 10
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR18##
Claim 11
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR19##
Claim 12
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR20##
Claim 13
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR21##
Claim 14
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR22##
Claim 15
Dependent Claim
16 words
A spiro-(fluoren-9,4'-imidazolidine)-2',5'-dione or pharmaceutically acceptable salt thereof as recited in claim 1 having the formula ##STR23##
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |