Patent US4550208A successfully refreshed from Google Patents.
US4550208A
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Preparation of 4,4'-diaminobenzophenones
Assignee: BASF SE
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Filing: 1984-11-21
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Granted: 1985-10-29
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Expires: 2004-11-21
Abstract
Abstract 4,4'-diaminobenzophenones of the formula I ##STR1## where the rings A and B can be further substituted, are prepared by a process in which a compound of the formula II ##STR2## where the rings A, B and E can be substituted, is oxidized with aqueous nitric acid in the presence of nitrobenzene or of an alkanoic acid and under superatmospheric pressure, and the reaction product is cleaved. The process according to the invention gives the compounds of the formula I in high yield and purity.
Inventors
- 👤 Walter Disteldorf
- 👤 Wolfgang Eisfeld
- 👤 Rolf-Dieter Kohler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:24
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
67 words
A process for the preparation of a 4,4'-diaminobenzophenone of the formula I ##STR7## where the rings A and B can be further substituted, wherein a compound of the formula II ##STR8## where the rings A, B and E can be substituted, is oxidized with aqueous nitric acid in the presence of nitrobenzene or of an alkanoic acid and under superatmospheric pressure, and the reaction product is cleaved.
Claim 2
Dependent Claim
67 words
A process for the preparation of a 4,4'-diaminobenzophenone of the formula I ##STR7## where the rings A and B can be further substituted, wherein a compound of the formula II ##STR8## where the rings A, B and E can be substituted, is oxidized with aqueous nitric acid in the presence of nitrobenzene or of an alkanoic acid and under superatmospheric pressure, and the reaction product is cleaved.
Claim 3
Dependent Claim
20 words
A process as claimed in claim 1, wherein the oxidation is carried out in the presence of an alkanoic acid.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 1, wherein the oxidation is carried out in the presence of acetic acid or propionic acid or a mixture of these acids.
Claim 5
Dependent Claim
29 words
A process as claimed in claim 1, wherein the oxidation is carried out using nitric acid having a concentration of from 0.5 to 15%, preferably from 1 to 4%.
Claim 6
Dependent Claim
19 words
A process as claimed in claim 1, wherein the oxidation is carried out at from 150° to 170° C.
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) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |