US4758667A
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Process for the preparation of 2-(imidazolin-2-yl)-3-pyridine- and -3-quinolinecarboxylic acids
Assignee: Novartis Corp
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Filing: 1987-02-05
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Granted: 1988-07-19
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Expires: 2007-02-05
Abstract
Abstract There is disclosed a process for the preparation of 2-(imidazolin-2-yl)-3-pyridine and -3-quinolinecarboxylic acids of formula ##STR1## wherein R 1 is hydrogen or C 1 -C 4 alkyl, R 2 is hydrogen, halogen, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, C 1 -C 4 alkoxy, phenyl or phenyl-C 1 -C 4 alkyl, or phenyl or phenyl-C 1 -C 4 -alkyl, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, R 3 is hydrogen, C 1 -C 4 alkyl, phenyl, phenyl-C 1 -C 4 -alkyl, or phenyl or phenyl-C 1 -C 4 -alkyl, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, R 2 and R 3 together are 1,3-butadienylene which can be substituted by halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkyl, C 1 -C 4 alkylsulfonyl, nitro, cyano, phenyl, phenoxy, or phenyl or phenoxy, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, and R 4 and R 5 are each independently of the other C 1 -C 4 alkyl. In this process, the 2-(imidazolin-2-yl)-3-pyridine- and -3-quinolinecarboxylic acids of the above formula are obtained by reacting a 2,3-pyridine- or 2,3-quinolinedidicarboxylic acid ester of formula ##STR2## wherein R 1 , and R 2 and R 3 are as defined above and R 6 is C 1 -C 8 alkyl, phenyl or C 1 -C 4 phenylalkyl with a 2-aminoalkanecarboxamide of formula ##STR3## wherein R 4 and R 5 are as defined above, in an inert solvent and in the presence of a strong base, direct to a salt of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of the above formula, from which the free 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acids of the above formula are obtained by converting said salt into an aqueous solution and adding an acid. The 2-(imidazolin-2-yl)-3-pyridine- and -3-quinolinecarboxylic acids of the above formula have herbicidal properties and can be used for controlling undesired plant growth.
Inventors
- 👤 Henry Szczepanski
- 👤 Dieter Durr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:42
CPC Classifications
C; C07; C07D; C07D401/00; C07D401/02; C07D401/04
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
318 words
A process for the preparation of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I ##STR7## wherein R 1 is hydrogen or C 1 -C 4 alkyl, R 2 is hydrogen, halogen, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, C 1 -C 4 alkoxy, phenyl or phenyl-C 1 -C 4 -alkyl, or phenyl or phenyl-C 1 -C 4 -alkyl, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, R 3 is hydrogen, C 1 -C 4 alkyl, phenyl, phenyl-C 1 -C 4 -alkyl, or phenyl or phenyl-C 1 -C 4 -alkyl, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, R 2 and R 3 together are 1,3-butadienylene which can be substituted by halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkyl, C 1 -C 4 alkylsulfonyl, nitro, cyano, phenyl, phenoxy, or phenyl or phenoxy, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, and R 4 and R 5 are each independently of the other C 1 -C 4 alkyl, which process comprises reacting a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II ##STR8## wherein R 1 , R 2 and R 3 are as defined for formula I, and R 6 is C 1 -C 8 alkyl, phenyl or C 1 -C 4 phenylalkyl, with a 2-aminoalkanecarboxamide of formula III ##STR9## wherein R 4 and R 5 are as defined for formula I, in an inert solvent and in the presence of a strong base, at a temperature in the range from room temperature to the reflux temperature of the reaction mixture, dissolving the resultant salt of 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I in water, adjusting the pH of the aqueous solution to 1.5-4.5, and isolating the free 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I.
Claim 2
Dependent Claim
318 words
A process for the preparation of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I ##STR7## wherein R 1 is hydrogen or C 1 -C 4 alkyl, R 2 is hydrogen, halogen, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, C 1 -C 4 alkoxy, phenyl or phenyl-C 1 -C 4 -alkyl, or phenyl or phenyl-C 1 -C 4 -alkyl, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, R 3 is hydrogen, C 1 -C 4 alkyl, phenyl, phenyl-C 1 -C 4 -alkyl, or phenyl or phenyl-C 1 -C 4 -alkyl, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, R 2 and R 3 together are 1,3-butadienylene which can be substituted by halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkyl, C 1 -C 4 alkylsulfonyl, nitro, cyano, phenyl, phenoxy, or phenyl or phenoxy, each substituted by one C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, and R 4 and R 5 are each independently of the other C 1 -C 4 alkyl, which process comprises reacting a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II ##STR8## wherein R 1 , R 2 and R 3 are as defined for formula I, and R 6 is C 1 -C 8 alkyl, phenyl or C 1 -C 4 phenylalkyl, with a 2-aminoalkanecarboxamide of formula III ##STR9## wherein R 4 and R 5 are as defined for formula I, in an inert solvent and in the presence of a strong base, at a temperature in the range from room temperature to the reflux temperature of the reaction mixture, dissolving the resultant salt of 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I in water, adjusting the pH of the aqueous solution to 1.5-4.5, and isolating the free 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I.
Claim 3
Dependent Claim
30 words
A process according to claim 1, wherein the inert solvent is a liquid aromatic hydrocarbon or halogenated hydrocarbon, a C 1 -C 10 alkanol, tetrahydrofuran, dioxane, acetonitrile, N,N-dimethylformamide or dimethylsulfoxide.
Claim 4
Dependent Claim
17 words
A process according to claim 1, wherein the inert solvent is benzene, toluene, chlorobenzene or a xylene.
Claim 5
Dependent Claim
43 words
A process according to claim 1, wherein the reaction of a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III is carried out in the presence of an alkali metal hydroxide or alkali metal alcoholate as strong base.
Claim 6
Dependent Claim
26 words
A process according to claim 4, wherein 1.5 to 2.5 moles of base are used per mole of 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II.
Claim 7
Dependent Claim
46 words
A process according to claim 1, wherein the reaction of a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III is carried out in the presence of an alkali metal alcoholate which is derived from a C 1 -C 4 alkanol.
Claim 8
Dependent Claim
34 words
A process according to claim 6, wherein the reaction of a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III is carried out in the presence of potassium tert-butylate.
Claim 9
Dependent Claim
37 words
A process according to claim 1, wherein the reaction of a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III is carried out in the temperature range from 50° to 90° C.
Claim 10
Dependent Claim
56 words
A process according to claim 1, wherein the salt of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I, obtained by reacting a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III, is isolated by filtration from the reaction mixture and converted into an aqueous solution by dissolving said salt in water.
Claim 11
Dependent Claim
51 words
A process according to claim 1, wherein the salt of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I, obtained by reacting a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III, is converted into an aqueous solution by direct addition of water to the reaction mixture.
Claim 12
Dependent Claim
42 words
A process according to claim 1, wherein the 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I is recovered from the aqueous solution of its salt by adjusting the pH of the aqueous solution to 3-4 by addition of hydrochloric acid or sulfuric acid.
Claim 13
Dependent Claim
74 words
A process for the preparation of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I, wherein R 1 is hydrogen, R 2 and R 3 are each independently of the other hydrogen, C 1 -C 2 alkyl, C 1 -C 2 haloalkyl, C 1 -C 2 alkoxy or halogen, and R 2 and R 3 together are 1,3-butadienylene, and R 4 and R 5 are each independently of the other C 1 -C 3 alkyl.
Claim 14
Dependent Claim
74 words
A process for the preparation of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I, wherein R 1 is hydrogen, R 2 and R 3 are each independently of the other hydrogen, C 1 -C 2 alkyl, C 1 -C 2 haloalkyl, C 1 -C 2 alkoxy or halogen, and R 2 and R 3 together are 1,3-butadienylene, and R 4 and R 5 are each independently of the other C 1 -C 3 alkyl.
Claim 15
Dependent Claim
50 words
A process for the preparation of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I, wherein R 1 is hydrogen, R 2 and R 3 are each independently of the other C 1 -C 2 alkyl or halogen and together are 1,3-butadienylene, R 4 is methyl and R 5 is isopropyl.
Claim 16
Dependent Claim
50 words
A process for the preparation of a 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I, wherein R 1 is hydrogen, R 2 and R 3 are each independently of the other C 1 -C 2 alkyl or halogen and together are 1,3-butadienylene, R 4 is methyl and R 5 is isopropyl.
Claim 17
Dependent Claim
124 words
A process according to claim 1, which comprises carrying out the reaction of a 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II with a 2-aminoalkanecarboxamide of formula III in the presence of 1.5 to 2.5 moles of an alkali metal alcoholate per mole of diester of formula II, at a temperature in the range from 50° to 90° C., and in a liquid aromatic hydrocarbon or halogenated hydrocarbon, converting the isolated salt of the resultant 2-(imidazolin-2-yl)-3-pyridine- or -3-quinolinecarboxylic acid of formula I into an aqueous solution by addition of water, separating the organic phase, adjusting the pH of the aqueous phase to 3-4 by addition of aqueous hydrochloric acid or aqueous sulfuric acid, and isolating the free 2-(imidazolin-2-yl)-3-pyridine or -3-quinolinecarboxylic acid of formula I.
Claim 18
Dependent Claim
26 words
A process according to claim 1, wherein 1.5 to 2.5 moles of base are used per mole of 2,3-pyridine- or 2,3-quinolinedicarboxylic acid ester of formula II.
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) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |