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Patent US2566357A successfully refreshed from Google Patents.
US2566357A
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Synthesis of di-aryl cyclic ethers
Assignee: Individual
•
Filing: 1949-02-28
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Granted: 1951-09-04
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Expires: 1969-02-28
Abstract
No abstract record available.
Inventors
- 👤 Orchin Milton
- 👤 Woolfolk Elkin Oscar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:57
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/78; C07C; C07C35/00; C07C35/22; C07C35/23; C07C35/36; C07D307/00; C07D307/77; C07D307/91
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
17 words
A METHOD FOR THE PREPARATION OF BENZOXANTHENE COMPRISING THE STEP OF DEHYDROGENATING A COMPOUND OF THE FORMULA
Claim 2
Independent Claim
17 words
A METHOD FOR THE PREPARATION OF BENZOXANTHENE COMPRISING THE STEP OF DEHYDROGENATING A COMPOUND OF THE FORMULA
References Cited (Backward Citations)
GB323806A
Cited
US1808349A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-09-03 | 1955-03-05 | 1955-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-09-03 | 1959-03-05 | 1959-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-09-03 | 1963-03-05 | 1963-09-04 | $7700.00 | Window Closed / Lapsed |