Patent US3697592A successfully refreshed from Google Patents.
US3697592A
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Polysubstituted dihydropyrenes
Assignee: Novartis Corp
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Filing: 1970-10-16
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Granted: 1972-10-10
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Expires: 1990-10-16
Abstract
Abstract Photochromic 1,3,6,8-tetra(lower)alkyl-15,16-dimethyl-15,16dihydropyrenes, 15,16-methylene-15,16-dihydropyrenes, 15,16methylene-15,16-dihydropyrenes and 1,3,6,8-tetra(lower)alkyl15,16-methylene-15,16-dihydropyrenes substituted in one or both of the 2- and 7-positions benzoyl, alkanoyl, alkanoyloxy, cyano, nitro, alkyl, Alpha -hydroxy-alkyl, Alpha -acyloxyalkyl, Alpha -isonitrosoalkyl, or acylamido groups are prepared via substitution of the parent hydrocarbon. A typical embodiment is 2-acetamido-7-nitro-1,3,6,8,15,16-hexamethyl-15,16dihydropyrene.
Inventors
- 👤 Luther A R Hall
- 👤 John A Gurney
- 👤 Harris B Renfroe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:47
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; C; C07; C07C; C07C13/00; C07C13/28; C07C13/32; C07C13/62; C07C13/66; C07C29/00; C07C29/132; C07C29/136; C07C29/14; C07C33/00; C07C33/05; C07C33/14; C07C37/00; C07C37/11; C07C37/115; C07C41/00; C07C41/01; C07C41/16; C07C41/18; C07C41/22; C07C41/30; C07C45/00; C07C45/27; C07C45/45; C07C45/46; C07C47/00; C07C47/38; C07C47/44; C07C47/445; C07C49/00; C07C49/527; C07C49/553; C12; C12C; C12C11/00; C12C11/02; C07C2603/00; C07C2603/02; C07C2603/04; C07C2603/30; C07C2603/34; C07C2603/38; C07C2603/40; C07C2603/42; C07C2603/50
Claims Analysis
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References Cited (Backward Citations)
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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) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |