U.S. patent application number 09/896086 was filed with the patent office on 2002-08-29 for process for the preparation of 2,3-pyridinedicarboximides.
This patent application is currently assigned to Intellectual Property Department, BASF Aktiengesellschaft. Invention is credited to Kremer, Kenneth Alfred Martin, Maulding, Donald Roy, Wu, Wen-Xue.
Application Number | 20020120143 09/896086 |
Document ID | / |
Family ID | 25359863 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020120143 |
Kind Code |
A1 |
Kremer, Kenneth Alfred Martin ;
et al. |
August 29, 2002 |
Process for the preparation of 2,3-pyridinedicarboximides
Abstract
There is provided a process for the preparation of
2,3-pyridinedicarboximi- des having the structural formula I 1 The
2,3-pyridinedicarboximides are useful as intermediates in the
preparation of herbicidal 2-(2-imidazolin-2-yl)nicotinic acids,
esters and salts.
Inventors: |
Kremer, Kenneth Alfred Martin;
(Lawrenceville, NJ) ; Wu, Wen-Xue; (Lawrenceville,
NJ) ; Maulding, Donald Roy; (Somerville, NJ) |
Correspondence
Address: |
BASF Corporation
Patent Law Department
P.O. Box 400
Princeton
NJ
08543-0400
US
|
Assignee: |
Intellectual Property Department,
BASF Aktiengesellschaft
Carl-Bosch-Strasse 38
Ludwigshafen
DE
D-67056
|
Family ID: |
25359863 |
Appl. No.: |
09/896086 |
Filed: |
June 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09896086 |
Jun 29, 2001 |
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09095913 |
Jun 11, 1998 |
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6316629 |
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09896086 |
Jun 29, 2001 |
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08872568 |
Jun 10, 1997 |
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5849916 |
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60019511 |
Jun 10, 1996 |
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Current U.S.
Class: |
546/113 |
Current CPC
Class: |
C07D 471/04
20130101 |
Class at
Publication: |
546/113 |
International
Class: |
C07D 471/02 |
Claims
We claim:
1. A process for the preparation of a 2,3-pyridinedicarboximide
having the structural formula I 23wherein R is hydrogen,
C.sub.1-C.sub.6alkyl or C.sub.1-C.sub.6alkoxymethyl; R.sub.1 is
hydrogen, C.sub.1-C.sub.6alkyl, C(O)R.sub.2, phenyl optionally
substituted with any combination of from one to four halogen,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or cyano groups,
benzyl optionally substituted on the phenyl ring with any
combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups, or 24R.sub.2 is
C.sub.1-C.sub.6alkyl, benzyl or phenyl optionally substituted with
any combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups; R.sub.3 and R.sub.4
are each independently C.sub.1-C.sub.4alkyl; and R.sub.5 is cyano
or CONH.sub.2, which process comprises reacting an oxime or
hydrazone having the structural formula II 25wherein R is as
described above; R.sub.6 is C.sub.1-C.sub.6alkyl; R.sub.7 is
OR.sub.8 or NR.sub.9R.sub.10; R.sub.8 is hydrogen,
C.sub.1-C.sub.6alkyl, C(O)R.sub.11, phenyl optionally substituted
with any combination of from one to four halogen,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or cyano groups,
or benzyl optionally substituted on the phenyl ring with any
combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups; R.sub.11 is
C.sub.1-C.sub.6alkyl, OR.sub.12, NR.sub.12R.sub.13, benzyl or
phenyl optionally substituted with any combination of from one to
four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or
cyano groups; R.sub.12 and R.sub.13 are each independently
hydrogen, C.sub.1-C.sub.6alkyl, benzyl or phenyl optionally
substituted with any combination of from one to four halogen,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or cyano groups;
and R.sub.9 and R.sub.10 are each independently hydrogen,
C.sub.1-C.sub.6alkyl, benzyl or phenyl optionally substituted with
any combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups, with a maleimide
having the structural formula III 26wherein R.sub.1 is as described
above.
2. The process according to claim 1 wherein R is hydrogen,
C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4alkoxymethyl; R.sub.1 is
hydrogen, C.sub.1-C.sub.4alkyl, phenyl optionally substituted with
any combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups, or 27R.sub.6 is
C.sub.1-C.sub.4alkyl; R.sub.7 is OR.sub.8; and R.sub.8 is hydrogen
or C.sub.1-C.sub.6alkyl.
3. The process according to claim 2 wherein R is hydrogen, methyl,
ethyl or methoxymethyl; R.sub.1 is methyl, phenyl or 28R.sub.6 is
methyl or ethyl; and R.sub.8 is hydrogen or methyl.
4. The process according to claim 1 wherein the formula II oxime or
hydrazone is reacted with the formula III maleimide in the presence
of a solvent.
5. The process according to claim 2 wherein the solvent is selected
from the group consisting of an aromatic hydrocarbon, a halogenated
aromatic hydrocarbon, a polynuclear aromatic hydrocarbon, a glycol,
an alkanoic acid, an alkanoic acid/water mixture, acetonitrile, an
acetonitrile/water mixture, and mixtures thereof, and the boiling
point of the solvent is at least about 60.degree. C.
6. The process according to claim 5 wherein the solvent is selected
from the group consisting of toluene, a xylene, mesitylene,
acetonitrile, an acetonitrile/water mixture, acetic acid and
mixtures thereof.
7. The process according to claim 6 wherein the solvent is toluene
or acetonitrile.
8. The process according to claim 1 wherein the formula II oxime is
reacted with the formula III maleimide at a temperature of about
60.degree. C. to 160.degree. C.
9. The process according to claim 8 wherein the temperature is
about 75.degree. C. to 135.degree. C.
10. The process according to claim 1 wherein the formula II
hydrazone is reacted with the formula III maleimide at a
temperature of about 20.degree. C. to 160.degree. C.
11. The process according to claim 10 wherein the temperature is
about 20.degree. C. to 135.degree. C.
12. The process according to claim 1 further comprising a Lewis
acid.
13. The process according to claim 12 wherein the Lewis acid is
aluminum chloride or titanium(IV) chloride.
14. The process according to claim 1 further comprising a base when
R is C.sub.1-C.sub.6alkoxymethyl.
15. The process according to claim 14 wherein the base is selected
from the group consisting of a tri(C.sub.2-C.sub.4alkyl)amine, an
alkali metal acetate and mixtures thereof.
16. A compound having the structural formula 29wherein R is
hydrogen, C.sub.1-C.sub.6alkyl or C.sub.1-C.sub.6alkoxymethyl;
R.sub.6 is C.sub.1-C.sub.4alkyl; R.sub.8 is hydrogen,
C.sub.1-C.sub.6alkyl, C(O)R.sub.11. phenyl optionally substituted
with any combination of from one to four halogen,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or cyano groups,
or benzyl optionally substituted on the phenyl ring with any
combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or -cyano groups; R.sub.11 is
C.sub.1-C.sub.6alkyl, OR.sub.12, NR.sub.12R.sub.13, benzyl or
phenyl optionally substituted with any combination of from one to
four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or
cyano groups; and R.sub.12 and R.sub.13 are each independently
hydrogen, C.sub.1-C.sub.6alkyl, benzyl or phenyl optionally
substituted with any combination of from one to four halogen,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, nitro or cyano groups,
and the cis and trans isomers thereof.
17. The compound according to claim 16 wherein R is hydrogen,
C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4alkoxymethyl; R.sub.6 is
C.sub.1-C.sub.4alkyl; and R.sub.8 is hydrogen or
C.sub.1-C.sub.6alkyl.
18. The compound according to claim 17 wherein R is hydrogen,
methyl, ethyl or methoxymethyl; R.sub.6 is methyl or ethyl; and
R.sub.8 is hydrogen or methyl.
19. The compound according to claim 18 selected from the group
consisting of the O-methyloxime of
3-ethoxy-2-methyl-2-propen-1-one; the O-methyloxime of
.sup.3-methoxy-2-(methoxymethyl)-2-propen-1-one; the oxime of
3-ethoxy-2-methyl-2-propen-1-one; and the oxime of
3-methoxy-2-(methoxymethyl)-2-propen-1-one.
20. A process for the preparation of a herbicidal imidazolinone
compound having the formula XII 30wherein R is as defined in claim
1; R.sub.14 is C.sub.1-C.sub.4 alkyl; R.sub.15 is C.sub.1-C.sub.4
alkyl, C.sub.3-C.sub.6 cycloalkyl or R.sub.14 and R.sub.15 when
taken together with the atom to which they are attached, represent
a C.sub.3-C.sub.6 cycloalkyl group optionally substituted with
methyl and R.sub.16 is hydrogen, diloweralkylimino,
C.sub.1-C.sub.12 alkyl optionally substituted with one of the
following groups: C.sub.1-C.sub.3 alkoxy, halogen, hydroxy,
C.sub.3-C.sub.6 cycloalkyl, benzyloxy, furyl, phenyl, halophenyl,
lower alkylphenyl, lower alkoxyphenyl, nitrophenyl, carboxyl,
loweralkoxycarbonyl, cyano or triloweralkylammonium;
C.sub.3-C.sub.12 alkenyl optionally substituted with one of the
following groups: C.sub.1-C.sub.3 alkoxy, phenyl, halogen or
loweralkoxycarbonyl or with two C.sub.1-C.sub.3 alkoxy groups or
two halogen groups; C.sub.3-C.sub.6 cycloalkyl optionally
substituted with one or two C.sub.1-C.sub.3 alkyl groups; or a
cation which process comprises: (a) preparing a compound having the
formula I 31wherein R and R.sub.1 are as defined in claim 1 by a
process as claimed in claim 1; and (b) converting the compound
having formula I into the compound having the formula XII.
Description
BACKGROUND OF THE INVENTION
[0001] 2,3-Pyridinedicarboximides are useful as intermediates in
the preparation of herbicidal 2-(2-imidazolin-2-yl)nicotinic acids,
esters and salts. Methods for the preparation of
2,3-pyridinedicarboximides are known in the art (see, e.g., U.S.
Pat. No. 4,748,244; U.S. Pat. No. 4,754,033 and EP 308,084-A1).
However, the methods described in those patents and patent
application are not entirely satisfactory for the commercial
manufacture of 2,3-pyridinedicarboximides.
[0002] It is, therefore, an object of the present invention to
provide an effective and efficient process for the preparation of
2,3-pyridinedicarboximides.
[0003] It is also an object of the present invention to provide a
compound which is useful in the process of this invention.
[0004] These and other objects and features of the present
invention will become more apparent from the detailed description
thereof set forth below.
SUMMARY OF THE INVENTION
[0005] The present invention provides an effective and efficient
process for the preparation of a 2,3-pyridinedicarboximide having
the structural formula I 2
[0006] wherein
[0007] R is hydrogen, C.sub.1-C.sub.6alkyl or
C.sub.1-C.sub.6alkoxymethyl;
[0008] R.sub.1 is hydrogen, C.sub.1-C.sub.6alkyl, C(O)R.sub.2,
[0009] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups,
[0010] benzyl optionally substituted on the phenyl ring with any
combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups, or 3
[0011] R.sub.2 is C.sub.1-C.sub.6alkyl, benzyl or
[0012] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups;
[0013] R.sub.3 and R.sub.4 are each independently
C.sub.1-C.sub.4alkyl; and
[0014] R.sub.5 is cyano or CONH.sub.2,
[0015] which process comprises reacting an oxime or hydrazone
having the structural formula II 4
[0016] wherein
[0017] R is as described above;
[0018] R.sub.6 is C.sub.1-C.sub.6alkyl;
[0019] R.sub.7 is OR.sub.8 or NR.sub.9R.sub.10;
[0020] R.sub.8 is hydrogen, C.sub.1-C.sub.6alkyl, C(O)R.sub.11,
[0021] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups, or
[0022] benzyl optionally substituted on the phenyl ring with any
combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups;
[0023] R.sub.11 is C.sub.1-C.sub.6alkyl, OR.sub.12,
NR.sub.12R.sub.13, benzyl or
[0024] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups;
[0025] R.sub.12 and R.sub.13 are each independently hydrogen,
C.sub.1-C.sub.6alkyl, benzyl or
[0026] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups; and
[0027] R.sub.9 and R.sub.10 are each independently hydrogen,
C.sub.1-C.sub.6alkyl, benzyl or
[0028] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups,
[0029] with a maleimide having the structural formula III 5
[0030] wherein R.sub.1 is as described above.
[0031] This invention also relates to the formula II oximes
described hereinabove.
DETAILED DESCRIPTION OF THE INVENTION
[0032] In one preferred embodiment of the present invention, an
oxime or hydrazone represented by formula II is reacted with a
maleimide represented by formula III, preferably in a temperature
range of about 20.degree. C. to 160.degree. C., in the presence of
a solvent.
[0033] Advantageously, it has now been found that
2,3-pyridinedicarboximid- es may be obtained in high yield and/or
high purity by the effective and efficient process of the present
invention.
[0034] The 2,3-pyridinedicarboximides may be isolated by diluting
the reaction mixture with water and filtering the formula I product
from the aqueous mixture. The product formula I compounds may also
be isolated by concentrating the reaction mixture in vacuo and
filtering the formula I product from the concentrated mixture.
Alternatively, the reaction mixture may be integrated into the
process used to prepare the final herbicidal agent without
isolating the formula I compound.
[0035] Exemplary of halogen hereinabove are fluorine, chlorine,
bromine and iodine.
[0036] In another embodiment of the present invention, a Lewis acid
is present. Preferably, the Lewis acid is present in an amount up
to about one molar equivalent relative to the formula II compound
when R.sub.8 is hydrogen. Lewis acids suitable for use in the
present invention include any conventional Lewis acids. Preferred
Lewis acids include aluminum chloride and titanium(IV)
chloride.
[0037] Solvents suitable for use in the process of the present
invention preferably have a boiling point of at least about
60.degree. C. and include aromatic hydrocarbons such as toluene,
xylenes, mesitylene and mixtures thereof; halogenated aromatic
hydrocarbons such as mono- and dihalobenzenes and mixtures thereof;
polynuclear aromatic hydrocarbons such as naphthalene,
alkylnaphthalenes and mixtures thereof; ethers such as
tetrahydrofuran and mixtures thereof; glycols such as
1,2-diethoxyethane and mixtures thereof; an alkanoic acid such as
acetic acid, propionic acid and mixtures thereof; an alkanoic
acid/water mixture such as an acetic acid/water mixture;
acetonitrile; an acetonitrile/water mixture; and mixtures thereof.
Preferred solvents include toluene, xylenes, mesitylene,
acetonitrile, an acetonitrile/water mixture, acetic acid and
mixtures thereof with toluene and acetonitrile being more
preferred.
[0038] In another preferred embodiment of the present invention,
oximes of formula II wherein R.sub.7 is OR.sub.8 are reacted with
maleimides of formula III preferably at a temperature range of
about 60.degree. C. to 160.degree. C., more preferably about
75.degree. C. to 135.degree. C. And hydrazones of formula II
wherein R.sub.7 is NR.sub.9R.sub.10 are reacted with maleimides of
formula III preferably at a temperature range of about 20.degree.
C. to 160.degree. C., more preferably about 20.degree. C. to
135.degree. C.
[0039] In a further preferred embodiment of the present invention,
a base is present when R is C.sub.1-C.sub.6alkoxymethyl. The base
is used to reduce the amount of 5-methyl-2,3-pyridinedicarboximides
which are produced as undesirable by-products when R is
C.sub.1-C.sub.6alkoxymethyl- .
[0040] Bases suitable for use in the present invention include, but
are not limited to, tri(C.sub.2-C.sub.4alkyl)amines such as
triethylamine, N,N-diethylisopropylamine, N,N-diisopropylethylamine
and the like, alkali metal acetates such as sodium acetate,
potassium acetate and the like, and mixtures thereof. Preferred
bases include triethylamine, sodium acetate and potassium acetate.
The base is preferably present in an amount of at least about one
molar equivalent relative to the formula II compound.
[0041] In a further embodiment of the present invention, a phase
transfer catalyst is present when the base is present. Preferably,
the phase transfer catalyst is present when the alkali metal
acetate is present. Phase transfer catalysts suitable for use in
the present invention include any conventional phase transfer
catalysts. Preferred phase transfer catalysts include crown ethers
such as 18-crown-6 and 15-crown-5.
[0042] In a preferred process of the present invention,
[0043] R is hydrogen, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4alkoxymethyl;
[0044] R.sub.1 is hydrogen, C.sub.1-C.sub.4alkyl,
[0045] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups, or 6
[0046] R.sub.3 and R.sub.4 are each independently
C.sub.1-C.sub.4alkyl;
[0047] R.sub.5 is cyano or CONH.sub.2;
[0048] R.sub.6 is C.sub.1-C.sub.4alkyl;
[0049] R.sub.7 is OR.sub.8; and
[0050] R.sub.8 is hydrogen or C.sub.1-C.sub.6alkyl.
[0051] In a more preferred process of the present invention,
[0052] R is hydrogen, methyl, ethyl or methoxymethyl;
[0053] R.sub.1 is methyl, phenyl or 7
[0054] R.sub.5 is cyano or CONH.sub.2;
[0055] R.sub.6 is methyl or ethyl;
[0056] R.sub.7 is OR.sub.8; and
[0057] R.sub.8 is hydrogen or methyl.
[0058] Formula II oximes wherein
[0059] R.sub.7 is OR.sub.8; and
[0060] R.sub.8 is hydrogen, C.sub.1-C.sub.6alkyl,
[0061] phenyl optionally substituted with any combination of from
one to four halogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
nitro or cyano groups, or
[0062] benzyl optionally substituted on the phenyl ring with any
combination of from one to four halogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, nitro or cyano groups,
[0063] may be prepared by reacting a 3-alkoxy-2-propenal of formula
IV with a substituted hydroxylamine of formula V optionally in the
presence of a base. The reaction scheme is shown below in Flow
Diagram I. 8
[0064] Alternatively, oximes of formula II wherein R.sub.8 is
C.sub.1-C.sub.6alkyl may be prepared by reacting a formula II
compound wherein R.sub.8 is hydrogen with a dialkyl sulfate of
formula VI in the presence of a base such as sodium hydroxide or an
alkali metal alkoxide. The reaction scheme is shown in Flow Diagram
II. 9
[0065] Formula II oximes wherein R.sub.8 is C(O)R.sub.11 may be
prepared by reacting a formula II compound wherein R.sub.8 is
hydrogen with an acid chloride of formula VII or an anhydride of
formula VIII as shown in Flow Diagram III. 10
[0066] Formula II hydrazones may be prepared by reacting a
3-alkoxy-2-propenal of formula IV with a hydrazine of formula IX
optionally in the presence of an acid catalyst such as acetic acid.
The reaction scheme is shown in Flow Diagram IV. 11
[0067] 3-Alkoxy-2-propenal compounds of formula IV may be prepared
according to the procedures described by E. Breitmaier, et al in
Synthesis, pages 1-9 (1987). Maleimide compounds of formula III are
known in the art and may be prepared according to the procedures
described by M. Cava, et al in Organic Synthesis, 41, page 93
(1961).
[0068] Alternatively, formula IV compounds wherein R is
methoxymethyl may be prepared by reacting a
3-(dialkylamino)-2-propenal of formula X with formaldehyde and
methanol in the presence of a mineral acid such as sulfuric acid to
form a 3-(dialkylamino)-2-(methoxymethyl)-2-propenal of formula XI,
and reacting the formula XI compound with a base such as an alkali
metal hydroxide and a dialkyl sulfate of formula VI. The reaction
scheme is shown in Flow Diagram V. 12
[0069] The present invention also provides a process for the
preparation of a herbicidal
5-(alkoxymethyl)-2-(2-imidazolin-2-yl)-nicotinic acid, ester and
salt compound having the formula 13
[0070] wherein
[0071] R is as defined above;
[0072] R.sub.14 is C.sub.1-C.sub.4 alkyl;
[0073] R.sub.15 is C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.6
cycloalkyl or R.sub.14 and R.sub.1 when taken together with the
atom to which they are attached, represent a C.sub.3-C.sub.6
cycloalkyl group optionally substituted with methyl and
[0074] R.sub.16 is hydrogen, diloweralkylimino,
[0075] C.sub.1-C.sub.12 alkyl optionally substituted with one of
the following groups: C.sub.1-C.sub.3 alkoxy, halogen, hydroxy,
C.sub.3-C.sub.6 cycloalkyl, benzyloxy, furyl, phenyl, halophenyl,
lower alkylphenyl, lower alkoxyphenyl, nitrophenyl, carboxyl,
loweralkoxycarbonyl, cyano or triloweralkylammonium;
[0076] C.sub.3-C.sub.12 alkenyl optionally substituted with one of
the following groups: C.sub.1-C.sub.3 alkoxy, phenyl, halogen or
loweralkoxycarbonyl or with two C.sub.1-C.sub.3 alkoxy groups or
two halogen groups;
[0077] C.sub.3-C.sub.6 cycloalkyl optionally substituted with one
or two C.sub.1-C.sub.3 alkyl groups; or
[0078] a cation preferably selected from the group consisting of
alkali metals, alkaline earth metals, manganese, copper, iron,
zinc, cobalt, lead, silver, nickel, ammonium and organic
ammonium;
[0079] which process comprises:
[0080] (a) preparing a compound having the formula I 14
[0081] wherein R and R.sub.1 are as defined above by a process as
defined above; and
[0082] (b) converting the compound having formula I into the
compound having the formula XII.
[0083] The term "lower" as used above in relation to alkyl and
alkoxy groups means that the alkyl or alkoxy group contains 1 to 6,
preferably 1 to 4, carbon atoms.
[0084] The conversion of the compound having formula I into the
compound having formula XII may be carried out in a variety of
ways. One may plan routes by combining reactions known for the
conversion of one carboxylic acid derivative into another.
[0085] Methods that may be used to create the imidazolinone
herbicides are illustrated in the book "The Imidazolinone
Herbicides" edited by D. L. Shaner and S. L. O'Connor, published
1991 by CRC Press, Boca Raton, Florida with particular reference to
Chapter 2 entitled "Synthesis of the Imidazolinone Herbicides",
pages 8-14 and the references cited therein. The following patent
literature references also illustrate the methods that may be used
to convert the carboxylic acid derivatives into imidazolinone final
products:
[0086] U.S. Pat. Nos. 5,371,229; 5,334,576; 5,250,694; 5,276,157;
5,110,930; 5,122,608; 5,206,368; 4,925,944; 4,921,961; 4,959,476;
5,103,009; 4,816,588; 4,748,244; 4,754,033; 4,757,146; 4,798,619;
4,766,218; 5,001,254; 5,021,078; 4,723,011; 4,709,036; 4,658,030;
4,608,079; 4,719,303; 4,562,257; 4,518,780; 4,474,962; 4,623,726;
4,750,978; 4,638,068; 4,439,607; 4,459,408; 4,459,409; 4,460,776;
4,125,727 and 4,758,667, and European Patent Application Nos.
EP-A-0-041,623 and EP-A-0-308,084.
[0087] In order to facilitate a further understanding of the
invention, the following examples are presented primarily for the
purpose of illustrating more specific details thereof. The
invention should not be deemed limited by the examples as the full
scope of the invention is defined in the claims.
EXAMPLE 1
[0088] Preparation of the Oxime of
3-ethoxy-2-methyl-2-propen-1-one, (E)- and (Z)- 15
[0089] 3-Ethoxy-2-methyl-2-propenal, (E)- and (Z)- (30.0 g, 0.25
mol) is added dropwise to a mixture of hydroxylamine sulfate (33.0
g, 0.2 mol) and sodium acetate (33.4 g, 0.4 mol) in water (200 g).
The resultant reaction mixture is stirred overnight and filtered to
obtain a solid. The solid is washed with water and dried to give
the title product as a white solid (23.2 g, mp 78.degree. C., 71%
yield) Using essentially the same procedure, but substituting
methoxylamine hydrochloride for hydroxyl- amine sulfate, the
O-methyloxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)- and (Z)- is
obtained as a yellow oil.
EXAMPLE 2
[0090] Preparation of the O-methyloxime of
3-ethoxy-2-methyl-2-propen-1-on- e, (E)- and (Z)- 16
[0091] A mixture of the oxime of 3-ethoxy-2-methyl-2-propen-1-one,
(E)- and (z)- (0.5 g, 3.87 mmol) and potassium tert-butoxide (0.48
g, 4.2 mmol) in tetrahydrofuran is stirred for ten minutes at
10.degree. C., treated dropwise with dimethyl sulfate (0.59 g, 4.6
mmol), stirred for two hours and filtered. The resultant filtrate
is concentrated in vacuo to give the title product as a yellow oil
(0.74 g, 100% yield).
EXAMPLE 3
[0092] Preparation of 5-Methyl-N-phenyl-2,3-pyridine-dicarboximide
17
[0093] A solution of N-phenylmaleimide (1.69 g, 9.8 mmol) in
toluene (16 g) is refluxed for 24 hours. During the reflux period,
the O-methyloxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)- and
(Z)- (1.57 g, 11 mmol) is added portionwise to the reaction
mixture. The final reaction 10 mixture is then concentrated in
vacuo to give the title product as a orange solid (1.2 g, 52%
yield).
EXAMPLES 4-7
[0094] Using essentially the same procedure as described in Example
3, but substituting the oxime of 3-ethoxy-2-methyl-2-propen-1-one,
(E)- and (Z)- for the O-methyl-oxime of
3-ethoxy-2-methyl-2-propen-1-one, (E)- and (Z)-,
5-methyl-N-phenyl-2,3-pyridinedicarboximide is produced in the
yields shown in Table I.
1TABLE I Preparation of 5-Methyl-N-phenyl-2,3-pyrid-
inedicarboximide Exam- Equivalents of N- Lewis Acid/ Hours % ple
phenylmaleimide Equivalents Solvent Refluxed Yield 4 0.3
AlCl.sub.3/0.2 Toluene 27 20 5 0.3 TiCl.sub.4/0.3 Toluene 10 10 6
0.2 -- H.sub.2O/ 12 15 CH.sub.3CN (1:1) 7 2.0 -- CH.sub.3CO.sub.2H
9 15
EXAMPLE 8
[0095] Preparation of
3-(Dimethylamino)-2-(methoxymethyl)-2-propenal, (E)- and (Z)-
18
[0096] Concentrated sulfuric acid (1 mL) is slowly added to a
solution of 3-(dimethylamino)-2-propenal (200 g, 2.01 mol) and
paraformaldehyde (90 g, 3 mol) in methanol (1 L). The resultant
solution is ref luxed overnight, concentrated in vacuo to a volume
of 200 mL, diluted with toluene and distilled until the vapor
temperature is 105.degree. C. The solution is then concentrated in
vacuo to give the title product as an orange oil (251.4 g, 87%
yield).
EXAMPLE 9
[0097] Preparation of 3-Methoxy-2-(methoxymethyl)-2-propenal, (E)-
and (Z)- 19
[0098] A solution of
3-(dimethylamino)-2-(methoxymethyl)-2-propenal, (E)- and (Z)-
(53.06 g, 0.37 mol) and sodium hydroxide solution (29.7 g, 50%,
0.37 mol) in methanol (60 mL) is refluxed for 20 minutes and
concentrated in vacuo to obtain a white solid. A solution of the
solid in water (250 mL) is treated dropwise with dimethyl sulfate
(46.75 g, 0.37 mol), stirred at room temperature for one hour and
extracted with methylene chloride. The organic extract is dried
over anhydrous sodium sulfate, concentrated in vacuo and distilled
to give the title product as a colorless liquid (19.66 g, bp
80.degree. C./0.5 mm Hg, 41% yield).
EXAMPLE 10
[0099] Preparation of
5-(Methoxymethyl)-N-phenyl-2,3-pyridinedicarboximide 20
[0100] A solution of methoxyamine hydrochloride (1.7 g, 20 mmol)
and sodium acetate (2.1 g, 25.6 mmol) in water (30 mL) is treated
dropwise with 3-methoxy-2-(methoxymethyl)-2-propenal, (E)- and (Z)-
(2.2 g, 16.9 mmol), stirred at room temperature for 30 minutes and
extracted with methylene chloride. The organic extract is dried
over anhydrous sodium sulfate and concentrated in vacuo to obtain
the O-methyloxime of 3-methoxy-2-(methoxymethyl)-2-propen-1-one. A
mixture of the resultant O-methyloxime of
3-methoxy-2-(methoxymethyl)-2-propen-1-one, N-phenylmaleimide (2.9
g, 16.8 mmol) and diisopropylethylamine (2.2 g, 17.0 mmol) in
toluene (50 mL) is refluxed for 23 hours. During the reflux period,
additional N-phenylmaleimide (2.9 g, 16.8 mmol) is added to the
reaction mixture. The final reaction mixture is concentrated in
vacuo to give the title product as a solid (0.36 g, 8% yield)
having a 5-(methoxymethyl)-N-phenyl-2,3-pyridinedicarboximide to
5-methyl-N-phenyl-2,3-pyridinedicarboximide ratio of 50:1.
EXAMPLE 11
[0101] Preparation of 3-Ethoxy-2-methylacrolein Dimethylhydrazone,
(E)- and (Z)- 21
[0102] A mixture of 3-ethoxy-2-methyl-2-propenal, (E)- and (Z)-
(4.0 g, 35 mmol), 1,1-dimethylhydrazine (2.73 g, 46 mmol) and
acetic acid (0.04 g, 0.7 mmol) in diethyl ether is refluxed for one
hour, cooled, washed sequentially with water and brine, dried over
anhydrous magnesium sulfate, and concentrated in vacuo to give the
title product as a yellow oil.
EXAMPLE 12
[0103] Preparation of 5-Methyl-N-phenyl-2,3-pyridine-dicarboximide
from N-phenylmaleimide and 3-ethoxy-2-methylacrolein
Dimethylhydrazone, (E)- and (Z)- 22
[0104] A solution of N-phenylmaleimide (1.1 g, 6.4 mmol) in
acetonitrile is refluxed for 19 hours. During the reflux period,
3-ethoxy-2-methylacrolein dimethylhydrazone, (E)- and (Z)- (1.2 g,
7.6 mmol) is added portionwise to the reaction mixture. The final
reaction mixture is then concentrated in vacuo to give the title
product as a dark oil (0.23 g, 15% yield).
* * * * *