Patent DE587614C successfully refreshed from Google Patents.
Patent US2668858A successfully refreshed from Google Patents.
US2668858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for their preparation
Assignee: —
•
Filing: —
•
Granted: 1954-02-09
•
Expires: 1971-02-09
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:47
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/61; C07C45/67; C07C45/68; C07C45/72; C07C45/62; C07C45/65; C07C45/74; C07C45/75; C07C49/00; C07C49/587
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
37 words
A PROCESS FOR THE MANUFACTURE OF A HYDRINDENEDIONE DERIVATIVE, WHICH COMPRISES REACTING FORMALDEHYDE SIMULTANEOUSLY WITH AN OPEN-CHAIN KETO COMPOUND HAVING A CARBONYL GROUP IN B-POSITION AND WITH METHYL-CYCLOPENTANE-2,5-DIONE IN THE PRESENCE OF A CONDENSING AGENT. 4. $7-3,6-DIKETO-9-METHYL-HEXAHYDRINDENE.
Claim 2
Dependent Claim
37 words
A PROCESS FOR THE MANUFACTURE OF A HYDRINDENEDIONE DERIVATIVE, WHICH COMPRISES REACTING FORMALDEHYDE SIMULTANEOUSLY WITH AN OPEN-CHAIN KETO COMPOUND HAVING A CARBONYL GROUP IN B-POSITION AND WITH METHYL-CYCLOPENTANE-2,5-DIONE IN THE PRESENCE OF A CONDENSING AGENT. 4. $7-3,6-DIKETO-9-METHYL-HEXAHYDRINDENE.
References Cited (Backward Citations)
US2542223A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-02-08 | 1957-08-10 | 1958-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-08 | 1961-08-10 | 1962-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-08 | 1965-08-10 | 1966-02-09 | $7700.00 | Window Closed / Lapsed |