US4582910A
Expired / Lapsed
US
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Method for preparation of 4-halogenonaphthalic acid anhydrides
Assignee: Rain Carbon Germany GmbH
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Filing: 1985-02-19
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Granted: 1986-04-15
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Expires: 2005-02-19
Abstract
Abstract A method for the preparation of 4-halogenonaphthalic acid anhydrides by halogenation of an aqueous solution of an alkali salt of the naphthalic acid with halogen or alkali metal hypohalogenite wherein a solution of the alkali metal salt of the naphthalic acid is treated with a water soluble magnesium salt and at least an equal molar amount of an alkakli metal hydroxide, halogenating this reaction mixture at a temperature in the range of 10° to 25° C. and subsequently acidifying the reaction mixture. In a second embodiment of the invention, an aqueous solution of alkali metal carbonate is used in place of the magnesium salt and alkali metal hydroxide.
Inventors
- 👤 Winfried Orth
- 👤 Emmerich Pastorek
- 👤 Werner Fickert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:41
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/347; C07C51/363
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
85 words
A method for the preparation of 4-halogenonaphthalic acid anhydride comprising mixing a solution of an alkali metal salt of naphthalic acid with a water soluble magnesium salt and at least an equimolar amount of an alkali metal hydroxide to form a reaction mixture, halogenating said reaction mixture with halogen or alkali metal hypohalogenite at a temperature in the range of 10° to 25° C. to form a halogenated reaction mixture, and then treating the halogenated reaction mixture with an acid and recovering the desired product.
Claim 2
Independent Claim
85 words
A method for the preparation of 4-halogenonaphthalic acid anhydride comprising mixing a solution of an alkali metal salt of naphthalic acid with a water soluble magnesium salt and at least an equimolar amount of an alkali metal hydroxide to form a reaction mixture, halogenating said reaction mixture with halogen or alkali metal hypohalogenite at a temperature in the range of 10° to 25° C. to form a halogenated reaction mixture, and then treating the halogenated reaction mixture with an acid and recovering the desired product.
Claim 3
Dependent Claim
36 words
The method according to claim 1, wherein the reaction is carried out under intensive mixing in the presence of an inert solvent which is water insoluble and unreactive with halogen under the conditions of the reaction.
Claim 4
Dependent Claim
14 words
The method according to claim 1, wherein the bromochloride is used for said halogenating.
Claim 5
Dependent Claim
16 words
The method according to claim 1, wherein the magnesium salt is magnesium chloride or magnesium sulfate.
Claim 6
Dependent Claim
16 words
The method according to claim 1, wherein the magnesium salt is used as a solid salt.
Claim 7
Dependent Claim
19 words
The method according to claim 1, wherein the magnesium salt is used as an aqueous solution of the salt.
Claim 8
Dependent Claim
32 words
The method according to claim 1, further comprising initially forming a solution of an alkali metal salt of the naphthalic acid by mixing naphthalic acid anhydride with alkali metal hydroxide in water.
Claim 9
Dependent Claim
65 words
The method according to claim 1, wherein the halogen or alkali metal hypohalogenite is used in an amount less than double the molar amount of the naphthalic acid anhydride that is used, and wherein the reaction mixture is stirred 1 to 3 hours after the halogenating is carried out, and the temperature is increased to a temperature in the range up to about 50° C.
Claim 10
Dependent Claim
36 words
The method according to claim 8, wherein the reaction is carried out under intensive mixing in the presence of an inert solvent which is water insoluble and unreactive with halogen under the conditions of the reaction.
Claim 11
Dependent Claim
13 words
The method according to claim 9, wherein bromochloride is used in the halogenating.
Claim 12
Independent Claim
83 words
A method for the preparation of 4-halogenonaphthalic acid anhydride comprising mixing a solution of an alkali metal salt of naphthalic acid with alkali metal carbonate to form a reaction mixture having a pH in the range of 9.3 to 13 and halogenating said reaction mixture with halogen or alkali metal hypohalogenite, at a temperature in the range of 10° to 25° C. to form a halogenated reaction mixture and then treating the halogenated reaction mixture with an acid and recovering the desired product.
Claim 13
Independent Claim
83 words
A method for the preparation of 4-halogenonaphthalic acid anhydride comprising mixing a solution of an alkali metal salt of naphthalic acid with alkali metal carbonate to form a reaction mixture having a pH in the range of 9.3 to 13 and halogenating said reaction mixture with halogen or alkali metal hypohalogenite, at a temperature in the range of 10° to 25° C. to form a halogenated reaction mixture and then treating the halogenated reaction mixture with an acid and recovering the desired product.
Claim 14
Dependent Claim
36 words
The method according to claim 11, wherein the reaction is carried out under intensive mixing in the presence of an inert solvent which is water insoluble and unreactive with halogen under the conditions of the reaction.
Claim 15
Dependent Claim
13 words
The method according to claim 11, wherein the bromochloride is used for halogenating.
Claim 16
Dependent Claim
40 words
The method according to claim 11, further comprising initially forming a solution of an alkali metal salt of naphthalic acid by dissolving naphthalic acid anhydride in 2.1 to 5.5 times the molar amount of an aqueous alkali metal carbonate solution.
Claim 17
Dependent Claim
38 words
The method according to claim 14, further comprising wherein the reaction is carried out under intensive mixing in the presence of an inert solvent which is water insoluble and unreactive with halogen under the conditions of the reaction.
Claim 18
Dependent Claim
12 words
The method according to claim 14, wherein bromochloride is used for halogenating.
Claim 19
Dependent Claim
38 words
The method according to claim 11, further comprising initially forming a solution of an alkali metal salt of the naphthalic acid by mixing naphthalic acid anhydride with alkali metal hydroxide and treating the solution with alkali metal carbonate.
Claim 20
Dependent Claim
38 words
The method according to claim 17, further comprising wherein the reaction is carried out under intensive mixing in the presence of an inert solvent which is water insoluble and unreactive with halogen under the conditions of the reaction.
Claim 21
Dependent Claim
12 words
The method according to claim 18, wherein bromochloride is used for halogenating.
Claim 22
Dependent Claim
65 words
The method according to claim 11, wherein the halogen or alkali metal hypohalogenite is used in an amount less than double the molar amount of the naphthalic acid anhydride this is used, and wherein the reaction mixture is stirred 1 to 3 hours after the halogenating is carried out, and increasing the temperature to a temperature in the range of up to about 50° C.
Claim 23
Dependent Claim
36 words
The method according to claim 20, wherein the reaction is carried out under intensive mixing in the presence of an inert solvent which is water insoluble and unreactive with halogen under the conditions of the reaction.
Claim 24
Dependent Claim
13 words
The method according to claim 21, wherein bromochloride is used in the halogenating.
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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |