Patent US3872131A successfully refreshed from Google Patents.
US3872131A
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Method of preparing quinophthalone dyes
Assignee: GAF Corp
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Filing: 1971-10-01
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Granted: 1975-03-18
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Expires: 1991-10-01
Abstract
Abstract Quinophthalone dyes are prepared by condensation of 2-methyl-3hydroxycinchoninic acids with aryl polycarboxylic acids, their anhydrides or mixtures thereof in the presence of N-lower alkyl pyrrolidones as solvents for the reaction.
Inventors
- 👤 William E Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:09
CPC Classifications
C; C07; C07D; C07D215/00; C07D215/02; C07D215/16; C07D215/48; C07D215/50; C09; C09B; C09B25/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
27 words
AN IMPROVED PROCESS FOR THE PREPARATION OF 3''HYDROXYQUINOPHTHALONES CONSISTING ESSENTIALLY OF REACTING, AT A TEMPERATURE OF ABOUT 180*C TO ABOUT 220*C, A 2-METHYL-3HYDROXYCINCHONINIC ACID OF THE FORMULA:
Claim 2
Dependent Claim
27 words
AN IMPROVED PROCESS FOR THE PREPARATION OF 3''HYDROXYQUINOPHTHALONES CONSISTING ESSENTIALLY OF REACTING, AT A TEMPERATURE OF ABOUT 180*C TO ABOUT 220*C, A 2-METHYL-3HYDROXYCINCHONINIC ACID OF THE FORMULA:
Claim 3
Dependent Claim
17 words
The precess of claim 1 in which said reaction temperature is from about 195*C to about 205*C.
Claim 4
Dependent Claim
12 words
The process of claim 1 in which said pyrrolidone solvent is N-methyl-pyrrolidone.
Claim 5
Dependent Claim
13 words
The process of claim 3 in which said cinchoninic acid comprises 3-hydroxy-2-methylcinchoninic acid.
Claim 6
Dependent Claim
12 words
The process of claim 4 in which said anhydride comprises phthalic anhydride.
Claim 7
Dependent Claim
13 words
The process of claim 4 in which said anhydride comprises trimellitic acid anhydride.
Claim 8
Dependent Claim
35 words
The process of claim 1 in which said pyrrolidone solvent is employed in an amount within the range of from about 2 to about 10 moles per mole of reactants employed in said reaction mixture.
Claim 9
Dependent Claim
41 words
The process of claim 1 in which said aryl polycarboxylic acid reactant is employed in an amount within the range of from the stoichiometric amount for reaction with said cinchoninic acid up to an excess of about 100 weight % thereof.
Claim 10
Dependent Claim
28 words
An improved process for the preparation of 3-hydroxyquinophthalone consisting essentially of: a. reacting, at a temperature of about 180*C to about 220*C, a 2-methyl-3-hydroxycinchoninic acid of the formula:
Claim 11
Dependent Claim
28 words
An improved process for the preparation of 3-hydroxyquinophthalone consisting essentially of: a. reacting, at a temperature of about 180*C to about 220*C, a 2-methyl-3-hydroxycinchoninic acid of the formula:
Claim 12
Dependent Claim
22 words
The process of claim 9 in which said reaction mixture is cooled to a temperature of From about 50*C to about 80*C.
Claim 13
Dependent Claim
32 words
The process of claim 9 in which said product is separated from the reaction mixture by filtering the reaction mixture containing said precipitated product and said pyrrolidone solvent and lower alkyl alcohol.
Claim 14
Dependent Claim
12 words
The process of claim 9 in which said pyrrolidone solvent comprises N-methylpyrrolidone.
Claim 15
Dependent Claim
13 words
The process of claim 12 in which said cinchoninic acid comprises 3-hydroxy-2-methylcinchoninic acid.
Claim 16
Dependent Claim
12 words
The process of claim 13 in which said anhydride comprises phthalic anhydride.
Claim 17
Dependent Claim
13 words
The process of claim 13 in which said anhydride comprises trimellitic acid anhydride.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |