Patent US3042719A successfully refreshed from Google Patents.
US3042719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
N-acetyl aminophenol process
Assignee: Monsanto Chemicals Ltd
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Filing: 1960-02-29
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Granted: 1962-07-03
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Expires: 1980-02-29
Abstract
No abstract record available.
Inventors
- 👤 John H Hahn
- 👤 John F Quinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:26
CPC Classifications
C; C07; C07C; C07C233/00; C07C233/01; C07C233/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
119 words
IN THE PROCESS FOR THE PURIFICATION OF A CRUDE DISCOLORED N-ACETYL AMINOPHENOL SELECTED FROM THE GROUP CONSISTING OF N-ACETYL AMINOPHENOL AND LOWER ALKYL SUBSTITUTED N-ACETYL AMINOPHENOLS CONTAINING AS IMPURITIES PRODUCTS OF OXIDATION OF CORRESPONDING AMINOPHENOL THE STEPS WHICH COMPRISE ACIDIFYING AN AQUEOUS SOLUTION OF SAID CRUDE N-ACETYL AMINOPHENOL TO A PH OF FROM ABOUT 1 TO ABOUT 5 WITH A MINERAL ACID, FILTERING THE SOLUTION WHICH IS AT A TEMPERATURE OF FROM ABOUT 50*C. TO ABOUT 100*C. AND COOLING THE FILTRATE WHILE SLOWLY ADDING THERETO AT LEAST ABOUT 0.05 PART PER 100 PARTS OF N-ACETYL AMINOPHENOL OF AN ALKALINE REDUCING SULFITE AS THE NACETYL AMINOPHENOL CRYSTALLIZES FROM THE SOLUTION, THE FOREGOING STEPS BEING CARRIED OUT IN A NON-OXIDIZING ATMOSPHERE.
Claim 2
Dependent Claim
119 words
IN THE PROCESS FOR THE PURIFICATION OF A CRUDE DISCOLORED N-ACETYL AMINOPHENOL SELECTED FROM THE GROUP CONSISTING OF N-ACETYL AMINOPHENOL AND LOWER ALKYL SUBSTITUTED N-ACETYL AMINOPHENOLS CONTAINING AS IMPURITIES PRODUCTS OF OXIDATION OF CORRESPONDING AMINOPHENOL THE STEPS WHICH COMPRISE ACIDIFYING AN AQUEOUS SOLUTION OF SAID CRUDE N-ACETYL AMINOPHENOL TO A PH OF FROM ABOUT 1 TO ABOUT 5 WITH A MINERAL ACID, FILTERING THE SOLUTION WHICH IS AT A TEMPERATURE OF FROM ABOUT 50*C. TO ABOUT 100*C. AND COOLING THE FILTRATE WHILE SLOWLY ADDING THERETO AT LEAST ABOUT 0.05 PART PER 100 PARTS OF N-ACETYL AMINOPHENOL OF AN ALKALINE REDUCING SULFITE AS THE NACETYL AMINOPHENOL CRYSTALLIZES FROM THE SOLUTION, THE FOREGOING STEPS BEING CARRIED OUT IN A NON-OXIDIZING ATMOSPHERE.
References Cited (Backward Citations)
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US1878969A
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US2040183A
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US2394572A
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US2799692A
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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) | 1965-07-02 | 1966-01-01 | 1966-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-07-02 | 1970-01-01 | 1970-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-07-02 | 1974-01-01 | 1974-07-03 | $7700.00 | Window Closed / Lapsed |