US2821529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of linear quinacridones
Assignee: EIDP Inc
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Filing: 1955-07-22
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Granted: 1958-01-28
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Expires: 1975-07-22
Abstract
No abstract record available.
Inventors
- 👤 William S Struve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:53
CPC Classifications
C; C09; C09B; C09B63/00; C09B48/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
84 words
A PROCESS FOR PREPARING A QUINACRIDONE WHICH COMPRISES HEATING UNDER NON-OXIDIZING CONDITIONS A DIALKYL 2,5 - DIARYLAMINO - 3,6 - DIHYDRO - TEREPHTHALATE, HAVING FROM 1-3 CARBON ATOMS IN THE ALKYL GROUPS, IN AN INERT, HIGH BOILING LIQUID AT TEMPERATURES RANGING FROM ABOUT 225-300*C. THEREBY OBTAINING A DIHYDRO-QUINACRIDONE, SEPARATING SAID DIHYDRO-QUINACRIDEONE FROM THE REACTION MIXTURE, AND OXIDIZING THE LATTER COMPOUND WITH A MILD OXIDIZING AGENT TO A QUINACRIDONE, SAID OXIDIZING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF NITROBENZENEM-SODIUM SULFONATE, SODIUM POLYSULFIDE AND OXYGEN.
Claim 2
Dependent Claim
84 words
A PROCESS FOR PREPARING A QUINACRIDONE WHICH COMPRISES HEATING UNDER NON-OXIDIZING CONDITIONS A DIALKYL 2,5 - DIARYLAMINO - 3,6 - DIHYDRO - TEREPHTHALATE, HAVING FROM 1-3 CARBON ATOMS IN THE ALKYL GROUPS, IN AN INERT, HIGH BOILING LIQUID AT TEMPERATURES RANGING FROM ABOUT 225-300*C. THEREBY OBTAINING A DIHYDRO-QUINACRIDONE, SEPARATING SAID DIHYDRO-QUINACRIDEONE FROM THE REACTION MIXTURE, AND OXIDIZING THE LATTER COMPOUND WITH A MILD OXIDIZING AGENT TO A QUINACRIDONE, SAID OXIDIZING AGENT BEING SELECTED FROM THE GROUP CONSISTING OF NITROBENZENEM-SODIUM SULFONATE, SODIUM POLYSULFIDE AND OXYGEN.
References Cited (Backward Citations)
US2054100A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |