US4472307A
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Preparation of anilino azo carbazole dyestuffs prepared by diazotization by nitrosylsulphuric acid in acetic acid
Assignee: Sanofi Aventis Deutschland GmbH
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Filing: 1982-08-20
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Granted: 1984-09-18
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Expires: 2002-08-20
Abstract
Abstract An improved process for the preparation of azo dyestuffs of the formula ##STR1## comprising diazotizing a 2-halo-4-nitroaniline at 10° to 35° C. in 70 to 100 percent by weight strength acetic acid by means of nitrosylsulphuric acid, adjusting the acetic acid content of the resulting diazo solution to 60 to 85% by the addition of water, and at a temperature from 15° to 45° C. adding an appropriate carbazole to the diazo solution as a solid or in the form of a suspension in 60 to 100 percent strength by weight acetic acid and coupling the carbazole to the diazotized amine to produce said azo dyestuff and isolating the dyestuff.
Inventors
- 👤 Ulrich Buhler
- 👤 Wolfgang Bodenstedt
- 👤 Heinz Hanel
- 👤 Eberhardt Hebestreit
- 👤 Horst Tappe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:37
CPC Classifications
C; C09; C09B; C09B29/00; C09B29/34; C09B29/36; C09B29/3604; C09B29/3608; C09B41/00; C09B41/001; C09B41/002
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
183 words
In the process for preparation of azo dyestuffs of the formula ##STR7## wherein Hal is bromo or chloro and R is hydrogen or alkyl having 1 to 4 carbon atoms unsubstituted or substituted by hydroxyl, cyano, alkoxy having 1 to 4 carbon atoms, alkoxycarbonyl having 1 to 4 carbon atoms in the alkoxy moiety or alkoxyalkoxycarbonyl having 1 to 4 carbon atoms in each of the two alkoxy moieties, comprising diazotizing an amine of the formula ##STR8## in acetic acid with nitrosylsulphuric acid, coupling the diazotized amine with a carbazole of the formula ##STR9## and isolating the dyestuff after coupling is complete, wherein the improvement comprises diazotizing said amine at 10° to 35° C. in 70 to 100 percent by weight strength acetic acid by means of nitrosylsulphuric acid, adjusting the acetic acid content of the diazo solution to 60 to 85% by the addition of water, and at a temperature from 15° to 45° C. adding said carbazole to the diazo solution as a solid or in the form of a suspension in 60 to 100 percent strength by weight acetic acid.
Claim 2
Dependent Claim
183 words
In the process for preparation of azo dyestuffs of the formula ##STR7## wherein Hal is bromo or chloro and R is hydrogen or alkyl having 1 to 4 carbon atoms unsubstituted or substituted by hydroxyl, cyano, alkoxy having 1 to 4 carbon atoms, alkoxycarbonyl having 1 to 4 carbon atoms in the alkoxy moiety or alkoxyalkoxycarbonyl having 1 to 4 carbon atoms in each of the two alkoxy moieties, comprising diazotizing an amine of the formula ##STR8## in acetic acid with nitrosylsulphuric acid, coupling the diazotized amine with a carbazole of the formula ##STR9## and isolating the dyestuff after coupling is complete, wherein the improvement comprises diazotizing said amine at 10° to 35° C. in 70 to 100 percent by weight strength acetic acid by means of nitrosylsulphuric acid, adjusting the acetic acid content of the diazo solution to 60 to 85% by the addition of water, and at a temperature from 15° to 45° C. adding said carbazole to the diazo solution as a solid or in the form of a suspension in 60 to 100 percent strength by weight acetic acid.
Claim 3
Dependent Claim
25 words
The process according to claim 1 for preparation of said azo dyestuffs wherein R is hydrogen, alkyl having 1 to 4 carbon atoms or cyanoethyl.
Claim 4
Dependent Claim
23 words
The process according to claim 1 or claim 2 for preparation of said azo dyestuffs wherein Hal is chloro and R is hydrogen.
Claim 5
Dependent Claim
21 words
The process according to claim 1 wherein the amine is diazotized in 85 to 95 percent strength by weight acetic acid.
Claim 6
Dependent Claim
16 words
The process according to claim 1 wherein the amine is diazotized for 5 to 45 minutes.
Claim 7
Dependent Claim
30 words
The process according to claim 1 wherein after diazotization the acetic acid content of the diazo solution is adjusted to 68 to 73% by weight by the addition of water.
Claim 8
Dependent Claim
20 words
The process according to claim 1 wherein said carbazole is added to the diazo solution at 20° to 35° C.
Claim 9
Dependent Claim
20 words
The process according to claim 1 wherein said carbazole is added to the diazo solution in finely divided solid form.
Claim 10
Dependent Claim
17 words
The process according to claim 1 wherein prior to diazotization the amine is in finely divided form.
Claim 11
Dependent Claim
24 words
The process according to claim 1 wherein said carbazole is added to the diazo solution over a period of from 0.5 to 2 hours.
References Cited (Backward Citations)
DE2212755A1
Cited
DE2338089A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |