US5153350A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing 3,4,6-trifluorophithalonitrile
Assignee: Pfizer Inc
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Filing: 1991-05-16
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Granted: 1992-10-06
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Expires: 2011-05-16
Abstract
Abstract A process for preparing 3,4,6-trifluorophthalonitrile from 3,4,5,6-tetrachlorophthalonitrile comprising the sequential steps of reductively dechlorinating the tetrachlorophthalonitrile, in the presence of a metal in an aqueous acidic medium, to produce 3,4,6-trichlorophthalonitrile and then subjecting the trichlorophthalonitrile to a chlorine-fluorine exchange by reaction with a fluoride source in a polar aprotic solvent.
Inventors
- 👤 Tamim F. Braish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:11
CPC Classifications
C; C07; C07C; C07C255/00; C07C255/49; C07C255/50; C07C255/51
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
78 words
A process for preparing 3,4,6-trifluorophthalonitrile from 3,4,5,6-tetrachlorophthalonitrile, comprising the sequential steps of: reacting said tetrachlorophthalonitrile with a metal selected from the group consisting of zinc, tin, iron, nickel, aluminum, alloys thereof and amalgams thereof in the presence of an aqueous acid selected from the group consisting of sulfuric, hydrochloric, nitric, citric, acetic, oxalic, phthalic and benzoic acids in an aqueous medium to afford 3,4,6-trichlorophthalonitrile; and reacting said trichlorophthalonitrile with an alkali metal fluoride in a polar aprotic solvent.
Claim 2
Dependent Claim
78 words
A process for preparing 3,4,6-trifluorophthalonitrile from 3,4,5,6-tetrachlorophthalonitrile, comprising the sequential steps of: reacting said tetrachlorophthalonitrile with a metal selected from the group consisting of zinc, tin, iron, nickel, aluminum, alloys thereof and amalgams thereof in the presence of an aqueous acid selected from the group consisting of sulfuric, hydrochloric, nitric, citric, acetic, oxalic, phthalic and benzoic acids in an aqueous medium to afford 3,4,6-trichlorophthalonitrile; and reacting said trichlorophthalonitrile with an alkali metal fluoride in a polar aprotic solvent.
Claim 3
Dependent Claim
12 words
A process according to claim 1 wherein said acid is sulfuric acid.
Claim 4
Dependent Claim
11 words
A process according to claim 2 wherein said metal comprises zinc.
Claim 5
Dependent Claim
11 words
A process according to claim 3 wherein said solvent comprises tetrahydrofuran.
Claim 6
Dependent Claim
12 words
A process according to claim 1 wherein said alkali metal is potassium.
Claim 7
Dependent Claim
12 words
A process according to claim 4 wherein said solvent comprises tetramethylene sulfone.
Claim 8
Dependent Claim
12 words
A process according to claim 5 wherein said solvent comprises tetramethylene sulfone.
Claim 9
Dependent Claim
28 words
A process according to claim 7 wherein said first reaction occurs under conditions including a temperature of about 60° C. and a reaction time of about 5 minutes.
Claim 10
Dependent Claim
32 words
A process according to claim 8 wherein said chlorine-fluorine exchange occurs under conditions including a temperature between about 155° C. and about 185° C. and a reaction time of about 6 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-06 | 1996-04-06 | 1996-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-06 | 2000-04-06 | 2000-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-06 | 2004-04-06 | 2004-10-06 | $7700.00 | Window Closed / Lapsed |