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US4978768A
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Process for the preparation of alkyl esters of tetrachloro-2-cyano-benzoic acid
Assignee: BASF Corp
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Filing: 1987-01-08
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Granted: 1990-12-18
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Expires: 2007-01-08
Abstract
Abstract Tetrachloro-2-cyanobenzoic acid alkyl esters of formula ##STR1## wherein R is C 1 -C 5 alkyl, can be very conveniently prepared by (a) reacting the ammonium salt of tetrachloro-2-cyanobenzoic acid, in the presence of water and an inert organic solvent, with a hydroxide of formula MOH, wherein M is Na or K, and removing the ammonia evolved, and (b) reacting the resultant salt of the formula ##STR2## wherein M is as defined above, with at least 1 mole of a dialkyl sulfate of formula SO 2 (OR) 2 or an alkyl halide of formula RHal, wherein R is as defined above and Hal is Cl, Br, I or F, also in the presence of water and an inert organic solvent.
Inventors
- 👤 Jost VON DER Crone
- 👤 Gonzague Overney
- 👤 Peter Dario
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:57
CPC Classifications
C; C07; C07C; C07C255/00; C07C255/49; C07C255/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
141 words
A process for the preparation of a tetrachloro-2-cyanobenzoic acid alkyl ester of formula I ##STR5## wherein R is C 1 -C 5 -alkyl, which process comprises (a) reacting the ammonium salt of tetrachloro-2-cyanobenzoic acid, in the presence of water and an inert organic solvent, with a hydroxide of formula MOH, wherein M is Na or K, and removing the ammonia evolved, and (b) reacting the resultant salt of formula II ##STR6## obtained substantially in pure form in step (a), wherein M is as defined above, with 1 to 1.5 moles of a dialkyl sulfate of formula SO 2 (OR) 2 or an alkyl halide of formula RHal, wherein R is as defined above and Hal is Cl, Br, I or F per mole of said resultant salt of formula II, also in the presence of water and an inert organic solvent.
Claim 2
Dependent Claim
141 words
A process for the preparation of a tetrachloro-2-cyanobenzoic acid alkyl ester of formula I ##STR5## wherein R is C 1 -C 5 -alkyl, which process comprises (a) reacting the ammonium salt of tetrachloro-2-cyanobenzoic acid, in the presence of water and an inert organic solvent, with a hydroxide of formula MOH, wherein M is Na or K, and removing the ammonia evolved, and (b) reacting the resultant salt of formula II ##STR6## obtained substantially in pure form in step (a), wherein M is as defined above, with 1 to 1.5 moles of a dialkyl sulfate of formula SO 2 (OR) 2 or an alkyl halide of formula RHal, wherein R is as defined above and Hal is Cl, Br, I or F per mole of said resultant salt of formula II, also in the presence of water and an inert organic solvent.
Claim 3
Dependent Claim
11 words
A process according to claim 1, wherein the hydroxide is NaOH.
Claim 4
Dependent Claim
11 words
A process according to claim 1, wherein the hydroxide is KOH.
Claim 5
Dependent Claim
35 words
A process according to claim 1, which comprises using a dialkyl sulfate of formula SO 2 (OR) 2 or an alkyl halide of formula RHal, wherein R is methyl or ethyl and Hal is Cl.
Claim 6
Dependent Claim
23 words
A process according to claim 1, which comprises using a dialkyl sulfate of formula SO 2 (OR) 2 , wherein R is methyl.
Claim 7
Dependent Claim
25 words
A process according to claim 1, wherein the inert organic solvent is the same or different and is selected from toluene and methyl ethyl ketone.
Claim 8
Dependent Claim
20 words
A process according to claim 1, wherein toluene is used for step (a) and methyl ethyl ketone for step (b).
Claim 9
Dependent Claim
21 words
A process according to claim 1, wherein the process is carried out in the temperature range from 20° to 90° C.
Claim 10
Dependent Claim
30 words
A process according to claim 1, wherein the temperature range for reaction step (a) is from 20° to 30° C. and for reaction step (b) from 50° to 70° C.
Claim 11
Dependent Claim
21 words
A process according to claim 1, wherein the volume ratio of water to inert organic solvent is from 1:3 to 3:1.
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) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |