US3773751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of nitroaromatic-azophenols
Assignee: Wyeth Holdings LLC
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Filing: 1969-09-08
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Granted: 1973-11-20
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Expires: 1989-09-08
Abstract
Abstract A PROCESS FOR COUPLING AN O-NITOANILINE AND A WATER IMMISCIBLE PARA-ALKYLPHENOL IN AN AQUEOUS BASIC REACTION MEDIUM TO OBTAIN A NITROPHENYLAZOPHENOL. THE NOVEL FEATURES OF THE PROCESS ARE THE PRESENCE OF AN INERT WATER IMMISCIBLE SOLVENT AND THE USE OF A SPARINGLY SOLUBLE BASE. TYPICALLY, O-NITROANILINE AND P-T-OCTYLPHENOL ARE COUPLED IN A REACTION SYSTEM HAVING SEPARATE AQUEOUS AND NAPHTHA PHASES AND EXCESS CALCIUM HYDROXIDE, SOME OF WHICH IS IN THE UNDISSOLVED SOLID STATE. THE RESULTANT AZOPHENOLS ARE IN PURE FORM AND CAN BE USED TO PREPARE 2-(HYDROXYPHENYL)BENZOTRIAZOLES.
Inventors
- 👤 H Brooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:37
CPC Classifications
C; C07; C07D; C07D249/00; C07D249/16; C07D249/18; C07D249/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |