US4345074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of a violet organic pigment, C.I. Pigment Violet 23
Assignee: Sanofi Aventis Deutschland GmbH
•
Filing: 1981-03-16
•
Granted: 1982-08-17
•
Expires: 2001-03-16
Abstract
Abstract In the process for the manufacture of the organic pigment of the formula ##STR1## by condensing and cyclizing 3-amino-9-ethylcarbazole with excess tetrachlorobenzoquinone in an organic solvent in the presence of acid acceptors, the improvement comprises carrying out the condensation reaction in the presence of 0.1 to 4% of water, relative to the total weight of the reaction mixture.
Inventors
- 👤 Theobald Hufnagel
- 👤 Manfred Hetschko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:23
CPC Classifications
C; C09; C09B; C09B19/00; C09B19/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
58 words
In the process for the manufacture of the organic pigment of the formula ##STR4## by condensing and cyclizing 3-amino-9-ethylcarbazole with excess tetrachlorobenzoquinone in an organic solvent in the presence of acid acceptors, the improvement comprises carrying out the condensation reaction in the presence of 0.1 to 4% of water, relative to the total weight of the reaction mixture.
Claim 2
Dependent Claim
58 words
In the process for the manufacture of the organic pigment of the formula ##STR4## by condensing and cyclizing 3-amino-9-ethylcarbazole with excess tetrachlorobenzoquinone in an organic solvent in the presence of acid acceptors, the improvement comprises carrying out the condensation reaction in the presence of 0.1 to 4% of water, relative to the total weight of the reaction mixture.
Claim 3
Dependent Claim
24 words
The process according to claim 1 wherein the condensation reaction is carried out in the presence of 0.15 to 1.8% by weight of water.
Claim 4
Dependent Claim
24 words
The process according to claim 1 wherein the condensation reaction is carried out in the presence of 0.25 to 0.85% by weight of water.
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) | 1985-08-16 | 1986-02-15 | 1986-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-16 | 1990-02-15 | 1990-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-16 | 1994-02-15 | 1994-08-17 | $7700.00 | Window Closed / Lapsed |