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US3843678A
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Process for the production of substituted indazoles
Assignee: Tenneco Chemicals Inc
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Filing: 1972-03-16
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Granted: 1974-10-22
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Expires: 1992-03-16
Abstract
Abstract Indazoles that have the structural formula WHEREIN X represents halogen, nitro, -SO2R, cyano, acoyl, acoylamino, aroylamino, alkyl, alkoxy, carboalkoxy, -COR, -CHO, or trihalomethyl; R represents alkylamino, hydroxy, halogen, alkyl, haloalkyl, phenyl, or substituted phenyl wherein the substituent is halogen, alkyl, or nitro; and n represents a number in the range of 1 to 4 are prepared by diazotizing the corresponding substituted o-toluidine in an aqueous mineral acid medium and adding the resulting diazonium salt solution to an aqueous solution containing basic anions, which is maintained at a pH of 4 to 10 and at a temperature of about 10*C. to 100*C. during the addition of the diazonium salt solution, and isolating the resulting indazole.
Inventors
- 👤 E Dibella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:34
CPC Classifications
C; C07; C07D; C07D231/00; C07D231/54; C07D231/56
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
12 words
IN THE PROCESS FOR THE PRODUCTION OF INDAZOLES HAVING THE STRUCTURAL FORMULA
Claim 2
Dependent Claim
12 words
IN THE PROCESS FOR THE PRODUCTION OF INDAZOLES HAVING THE STRUCTURAL FORMULA
Claim 3
Dependent Claim
53 words
The process of claim 1 wherein the substituted o-toluidine is dissolved in an aqueous mineral acid medium that contains 2 moles to 10 moles of mineral acid per mole of o-toluidine and the resulting solution is diluted with water to form a suspension of the acid salt of the o-toluidine in said medium.
Claim 4
Dependent Claim
77 words
The process of claim 1 wherein the suspension of the salt of the substituted o-toluidine in aqueous mineral acid medium is formed by heating the o-toluidine with an amount of an aqueous mineral acid that contains 1 mole to 3 moles of the acid per mole of the o-toluidine until complete solution is effected, and the resulting solution is cooled to form a suspension of the acid salt of the o-toluidine in the aqueous mineral acid medium.
Claim 5
Dependent Claim
30 words
The process of claim 1 wherein the reaction mixture is maintained at 60* to 100*C. during the addition of the diazonium salt solution to the aqueous alkali metal salt solution.
Claim 6
Dependent Claim
37 words
The process of claim 1 wherein the diazonium salt solution is added to an aqueous solution that contains at least 0.3 mole of said salt of a water-soluble acid per mole of diazonium salt in the solution.
Claim 7
Dependent Claim
106 words
The process of claim 1 wherein the diazonium salt solution is added in at least two portions to an aqueous solution that contains about 1 mole to 2 moles of the alkali metal salt of the water-soluble acid per mole of diazonium salt in said solution and after the addition of each portion an amount of an alkaline solution that is equivalent to the amount of diazonium salt that has been added is added to the reaction mixture to regenerate the alkali metal salt, a stoichiometric excess of said alkali metal salt being present in the reaction mixture throughout the addition of the diazonium salt solution.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the substituted o-toluidine that is diazotized has the structural formula
Claim 9
Dependent Claim
11 words
The process of claim 1 wherein the substituted o-toluidine is 2-amino-4-nitrotoluene.
Claim 10
Dependent Claim
12 words
In the process for the production of indazoles having the structural formula
Claim 11
Dependent Claim
12 words
In the process for the production of indazoles having the structural formula
Claim 12
Dependent Claim
10 words
The process of claim 9 wherein each Z represents halogen.
Claim 13
Dependent Claim
17 words
The process of claim 9 wherein m represents a number in the range of 1 to 3.
Claim 14
Dependent Claim
11 words
The process of claim 9 wherein the substituted o-toluidine is 2-amino-3,5-dichlorotoluene.
Claim 15
Dependent Claim
11 words
The process of claim 9 wherein the substituted o-toluidine is 2-amino-3,5-dibromotoluene.
Claim 16
Dependent Claim
30 words
The process of claim 9 wherein the reaction mixture is maintained at 60*C. to 80*C. while the diazonium salt solution is being added to the aqueous alkali metal salt solution.
Claim 17
Dependent Claim
36 words
The process of claim 9 wherein the diazonium salt solution is added to an aqueous sodium acetate solution that contains 1 mole to 20 moles of sodium acetate per mole of diazonium salt in said solution.
Claim 18
Dependent Claim
38 words
The process of claim 9 wherein the diazonium salt solution is added to an aqueous phosphate buffer system at pH 7 that contains 1 mole to 20 moles of phosphate per mole of diazonium salt in said solution.
Claim 19
Dependent Claim
99 words
The process of claim 9 wherein the diazonium salt solution is gradually added to an aqueous solution that contains about 1 mole to 2 moles of an aqueous phosphate buffer system at pH 7 per mole of said diazonium salt until the pH of the reaction mixture reaches about 6, aqueous alkaline solution is added to the reaction mixture until its pH reaches 8, and the alternate addition of diazonium salt solution and alkaline solution to maintain the pH of the reaction mixture between 5 and 8 is continued until all of the diazonium salt solution has been added.
Claim 20
Dependent Claim
60 words
The process of claim 9 wherein the diazonium salt solution and an aqueous alkaline solution are added simultaneously to an aqueous solution that contains about 1 mole to 2 moles of an aqueous phosphate buffer at pH 7 per mole of said diazonium salt at such rates that the pH of the reaction mixture is maintained between 5 and 8.
Claim 21
Dependent Claim
34 words
The process of claim 9 wherein the diazonium salt solution is added to an aqueous solution that contains 5 moles to 15 moles of sodium acetate per mole of diazonium salt in said solution.
Claim 22
Dependent Claim
35 words
The process of claim 1 wherein the diazonium salt solution is added to an aqueous solution that contains 5 moles to 15 moles of disodium hydrogen phosphate per mole of diazonium salt in said solution.
Claim 23
Dependent Claim
140 words
The process for the production of 5,7-dichloroindazole that comprises the steps of a. forming a suspension of 2-amino-3,5-dichlorotoluene bisulfate in aqueous sulfuric acid, said suspension containing 1 mole to 10 moles of sulfuric acid per mole of said bisulfate; b. adding to suspension at 5*C. to 10*C. an aqueous solution of sodium nitrite, thereby forming an aqueous solution of the diazonium salt of 2-amino-3,5-dichlorotoluene; c. adding said diazonium salt solution to an aqueous solution that contains about 1 mole to 20 moles per mole of said diazonium salt of an alkali metal salt of a water-soluble acid having a dissociation constant in the range of 1 X 10 8 to 1 X 10 5 while maintaining the temperature of the reaction mixture between 60*C. and 100*C. and its pH between 5 and 8 thereby forming 5,7-dichloroindazole; and d. isolating 5,7-dichloroindazole.
Claim 24
Dependent Claim
140 words
The process for the production of 5,7-dichloroindazole that comprises the steps of a. forming a suspension of 2-amino-3,5-dichlorotoluene bisulfate in aqueous sulfuric acid, said suspension containing 1 mole to 10 moles of sulfuric acid per mole of said bisulfate; b. adding to suspension at 5*C. to 10*C. an aqueous solution of sodium nitrite, thereby forming an aqueous solution of the diazonium salt of 2-amino-3,5-dichlorotoluene; c. adding said diazonium salt solution to an aqueous solution that contains about 1 mole to 20 moles per mole of said diazonium salt of an alkali metal salt of a water-soluble acid having a dissociation constant in the range of 1 X 10 8 to 1 X 10 5 while maintaining the temperature of the reaction mixture between 60*C. and 100*C. and its pH between 5 and 8 thereby forming 5,7-dichloroindazole; and d. isolating 5,7-dichloroindazole.
Claim 25
Dependent Claim
26 words
The process of claim 21 wherein in Step (c) the reaction mixture is maintained at 60*C. to 80*C. during the addition of the diazonium salt solution.
Claim 26
Dependent Claim
37 words
The process of claim 21 wherein in Step (c) the diazonium salt solution is added to an aqueous solution that contains 5 moles to 15 moles of sodium acetate per mole of diazonium salt in said solution.
Claim 27
Dependent Claim
103 words
The process of claim 21 wherein in Step (c) the diazonium salt solution is added in at least two portions to an aqueous solution that contains about 1 mole to 2 moles of alkali metal salt per mole of diazonium salt in said solution and after the addition of each portion the alkali metal salt is regenerated by adding to the reaction mixture an amount of sodium hydroxide that is equivalent to the amount of the diazonium salt that has been added, a stoichiometric excess of alkali metal salt being present in the reaction mixture throughout the addition of the diazonium salt solution.
Claim 28
Dependent Claim
60 words
The process of claim 21 wherein in Step (c) the diazonium salt solution is added gradually to an aqueous solution that contains about 1 mole to 2 moles per mole of a phosphate buffer system while the pH of the reaction mixture is maintained within the range of 6.0 to 8.0 by the intermittent addition of aqueous sodium hydroxide solution.
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) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |