US3694508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of p-aminophenol
Assignee: MALLINCKOTT CHEM WORKS
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Filing: 1969-10-16
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Granted: 1972-09-26
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Expires: 1989-10-16
Abstract
Abstract A process for the purification of crude p-aminophenol comprising admixing the crude p-aminophenol with a water-immiscible solvent which is substantially a non-solvent for p-aminophenol having a boiling point above 40*C. and a melting point below 50*C. and selected from the group consisting of esters or hydrocarbons, and mixtures thereof and subsequently separating purified paminophenol from said mixture.
Inventors
- 👤 Frank A Baron
- 👤 Roland G Benner
- 👤 Alan E Weinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:13
CPC Classifications
C; C07; C07C; C07C215/00; C07C215/74; C07C215/76
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
24 words
A method according to claim 1 wherein the amount of acetate present is from 0.2 to 10 parts by weight per part of p-aminophenol.
Claim 2
Dependent Claim
17 words
A method according to claim 1 wherein ammonia is employed to adjust the pH of said mixture.
Claim 3
Dependent Claim
12 words
A method according to claim 1 wherein said solvent is n-butyl acetate.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |