US3113137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for isomerizing stereoisomeric xanthene and thioxanthene compounds via the use of oxalic acid
Assignee: F Hoffmann La Roche AG
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Filing: 1960-06-22
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Granted: 1963-12-03
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Expires: 1980-06-22
Abstract
No abstract record available.
Inventors
- 👤 Schaeren Sidney Frank
- 👤 Schlapfer Reinhard
- 👤 Spiegelberg Hans
- 👤 Vaterlaus Bruno Peter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:29
CPC Classifications
C; C07; C07D; C07D337/00; C07D337/02; C07D337/06; C07D337/10; C07D337/12; C07D311/00; C07D311/02; C07D311/78; C07D311/80; C07D311/82; C07D311/90
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
22 words
A PROCESS FOR THE ISOMERIZATION OF MATERIAL SELECTED FROM THE GROUP CONSISTING OF: (A) A SUBSTANTIALLY STERICALLY UNIFORM BASE OF THE FORMULA
Claim 2
Dependent Claim
22 words
A PROCESS FOR THE ISOMERIZATION OF MATERIAL SELECTED FROM THE GROUP CONSISTING OF: (A) A SUBSTANTIALLY STERICALLY UNIFORM BASE OF THE FORMULA
Claim 3
Dependent Claim
51 words
A PROCESS WHICH COMPRISES SUBJECTING A MIXTURE COMPRISING 2-CHLORO-9-HYDROXY-9-(W-DIMETHYLAMINO-PROPYL)-THIOXANTHENE AND 2-CHLORO-9-(W-DIMETHYLAMINO-PROPYLIDENE)-THIOXANTHENE, AT LEAST A MAJOR PROPORTION OF THE LATTER BEING IN CIS FORM, TO THE ACTION OF EXCESS OXALIC ACID FOR AT LEAST ABOUT 30 MINUTES AT ABOUT 110*C., THEREBY FORMING A MIXTURE COMPRISING APPROXIMATELY EQUAL PROPORTIONS OF CIS- AND TRANS-2-CHLORO-9-(W-DIMETHYLAMINO-PROPYLIDENE)-THIOXANTHENE.
Claim 4
Dependent Claim
51 words
A PROCESS WHICH COMPRISES SUBJECTING A MIXTURE COMPRISING 2-CHLORO-9-HYDROXY-9-(W-DIMETHYLAMINO-PROPYL)-THIOXANTHENE AND 2-CHLORO-9-(W-DIMETHYLAMINO-PROPYLIDENE)-THIOXANTHENE, AT LEAST A MAJOR PROPORTION OF THE LATTER BEING IN CIS FORM, TO THE ACTION OF EXCESS OXALIC ACID FOR AT LEAST ABOUT 30 MINUTES AT ABOUT 110*C., THEREBY FORMING A MIXTURE COMPRISING APPROXIMATELY EQUAL PROPORTIONS OF CIS- AND TRANS-2-CHLORO-9-(W-DIMETHYLAMINO-PROPYLIDENE)-THIOXANTHENE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-12-02 | 1967-06-03 | 1967-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-12-02 | 1971-06-03 | 1971-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-12-02 | 1975-06-03 | 1975-12-03 | $7700.00 | Window Closed / Lapsed |