Process for the preparation of acylated cyclic...

Details Process for the preparation of acylated cyclic... Process for the preparation of acylated cyclic...

2000-04-18

2001-04-17

Richter, Johann (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Oxygen containing

C568S308000, C568S310000

Reexamination Certificate

active

06218579

ABSTRACT:

The present invention relates to the production of acylated cyclical 1,3-dicarbonyl compounds and in particular to the production of benzoyl-1,3-cyclohexanediones and cycloalkyl-1,3-cyclohexanediones.
The compounds produced by the process are known as herbicides and plant growth regulators. 2-(Substituted benzoyl)-1,3-cyclohexanediones are known as herbicides from, for example, U.S. Pat. No. 4,780,127, U.S. Pat. No. 4,806,146, U.S. Pat. No. 4,946,981, U.S. Pat. No. 5,006,158, WO 9408988 and WO 9404524. Cyclopropylcarbonyl-cyclohexanediones are known as plant growth regulators from, for example, EP126713. One method of producing these compounds is by re-arrangement of an enol ester. This method is described in U.S. Pat. No. 4,695,673. This process provides a means to obtain the desired compounds but the process also requires the use of a cyanide source as a catalyst. In WO 9622957 it was shown that in certain solvents the rearrangement of a cyclohexanedione enol ester would proceed in the absence of a cyanide catalyst. However the reactions proceeded much more slowly and produced a lower yield. There is therefore a continuing need for a rearrangement process which produces acceptable yields but which does not use a cyanide catalyst. It has surprisingly been found that azoles may be used in a cyanide-free rearrangement process.
According to the present invention there is provided a process for preparing a compound of Formula (I)
where Q completes an optionally substituted 5- or 6-member saturated carbocyclic ring and R is optionally substituted phenyl or optionally substituted C
3
-C
6
cycloalkyl which process comprises the rearrangement of a compound of Formula (II)
where Q and R are as defined in relation to Formula (I) in a polar aprotic, dipolar aprotic or aromatic hydrocarbon solvent in the presence of a moderate base and an azole.
The compounds of formula (I) may exist as one or more of the structural formulae shown below because of tautomerism.
The values of Q and R are as defined above.
The term “azole” refers to a five membered nitrogen-containing ring which is optionally substituted and which may be fused to other rings.
Optional substituents for the carbocyclic ring formed by Q include C
1-4
alkyl, C
1-4
haloalkyl, C
1-4
alkoxy, C
2-5
alkylene (in which case the compounds have a spiro structure) COC
1-4
alkyl, COOH, COOC
1-4
alkyl, phenyl, halophenyl, C
1-4
haloalkylphenyl, phenoxy halophenoxy, C
1-4
haloalkylphenoxy, or heterocyclic groups such as pyridyl or pyrimidinyl.
Optional substituents for the phenyl and cycloalkyl rings R include halogen, cyano, NO
2
, C
1-4
alkyl, C
1-4
haloalkyl, C
1-4
alkoxy, phenoxy, halogen substituted phenoxy, C
1-4
haloalkyl substituted phenoxy, R
b
S(O)
n
O
m
in which m is 0 or 1, n is 0, 1 or 2 and R
b
is C
1-4
alkyl, C
1-4
haloalkyl, phenyl or benzyl, NHCOR
c
in which R
c
is C
1-4
alkyl, NR
d
R
e
in which R
d
and R
e
independently are hydrogen or C
1-4
alkyl; R
f
C(O)— in which R
f
is hydrogen, C
1-4
alkyl, C
1-4
haloalkyl or C
1-4
alkoxy; SO
2
NR
g
R
h
in which R
g
and R
h
independently are hydrogen or C
1-4
alkyl; or any two adjacent substituents together with the carbon atoms to which they are attached form a 5 or 6 membered heterocyclic ring containing up to three heteroatoms selected from O, N or S and which may be optionally substituted by C
1-4
alkyl, C
1-4
haloalkyl, C
1-4
alkoxy, ═NOC
1-4
alkyl or halogen.
As used herein the term “alkyl”, refers to straight or branched chains. The term “haloalkyl” refers to an alkyl group substituted by at least one halogen. Similarly the term “haloalkoxy” refers to an alkoxy group substituted by at least one halogen. As used herein the term “halogen” refers to fluorine, chlorine, bromine and iodine.
As used herein the term “aryl” refers to aromatic carbocyclic ring systems such as phenyl or naphthyl, especially phenyl.
A preferred carbocyclic ring formed by Q is an optionally substituted cyclohexanedione.
One class of compounds of formula (I) is cyclohexanediones of formula (IA)
in which R
1
, R
2
, R
3
, R
4
, R
5
and R
6
are independently hydrogen or C
1-6
alkyl; R
7
is hydrogen, halogen, cyano, NO
2
, C
1-4
alkyl, C
1-4
haloalkyl, C
1-4
alkoxy or R
a
S in which R
a
is C
1-4
alkyl; R
8
, R
9
and R
10
independently are hydrogen, halogen, C
1-4
alkyl, C
1-4
alkoxy, C
1-4
haloalkyl, C
1-4
haloalkoxy, CN, NO
2
, phenoxy, phenoxy, halophenoxy or C
1-4
haloalkylphenoxy; R
b
S(O)n Om in which m is 0 or 1, n is 0, 1 or 2 and R
b
is C
1-4
alkyl, C
1-4
haloalkyl, phenyl or benzyl, NHCOR
c
in which R
c
is C
1-4
alkyl, NR
d
R
c
in which R
d
and R
e
independently are hydrogen or C
1-4
alkyl; R
f
C(O)— in which R
f
is hydrogen, C
1-4
alkyl, C
1-4
haloalkyl or C
1-4
alkoxy; SO
2
NR
g
R
h
in which R
g
and R
h
independently are hydrogen or C
1-4
alkyl; or any two of R
8
, R
9
and R
10
together with the carbon atoms to which they are attached form a 5 or 6 membered heterocyclic ring containing up to three heteroatoms selected from O, N or S and which may be optionally substituted by C
1-4
alkyl, C
1-4
haloalkyl, C
1-4
alkoxy, ═NOC
1-4
alkyl or halogen which are prepared from compounds of formula (IIA)
where R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
, R
8
, R
9
and R
10
are as defined in relation to Formula (IA).
A preferred group of compounds of Formula (IA) are those where R
1
, R
2
, R
3
, R
4
, R
5
and R
6
are independently hydrogen or C
1-6
alkyl; R
7
is halogen, cyano, NO
2
, C
1-4
alkyl, C
1-4
haloalkyl, C
1-4
alkoxy or R
a
S in which R
a
is C
1-4
alkyl; R
8
, R
9
and R
10
independently are hydrogen, halogen, C
1-4
alkyl, C
1-4
alkoxy, C
1-4
haloalkyl, C
1-4
haloalkoxy, CN, NO
2
, phenoxy or substituted phenoxy; R
b
S(O)n Om in which m is 0 or 1, n is 0, 1 or 2 and R
b
is C
1-4
alkyl, C
1-4
haloalkyl, phenyl or benzyl, NHCOR
c
in which R
c
is C
1-4
alkyl, NR
d
R
e
in which R
d
and R
e
independently are hydrogen or C
1-4
alkyl; R
f
C(O)— in which R
f
is hydrogen, C
1-4
alkyl, C
1-4
haloalkyl or C
1-4
alkoxy; or SO
2
NR
g
R
h
in which R
g
and R
h
independently are hydrogen or C
1-4
alkyl.
Preferably R
1
, R
2
, R
3
, R
4
, R
5
and R
6
are independently hydrogen or C
1-4
alkyl. More preferably R
1
, R
2
, R
5
and R
6
are hydrogen and R
3
and R
4
are independently hydrogen or methyl, especially hydrogen.
R
7
is preferably halogen or NO
2
. A preferred value for R
8
is hydrogen.
R
9
is preferably hydrogen or C
1-4
alkoxy, especially ethoxy. Most preferably R
9
is hydrogen.
Preferably R
10
is a group R
b
S(O)
n
Om where R
b
, n and m are as defined above. More preferably m is zero, n is 2 and R
b
is CH
3
or C
2
H
5
. Most preferably R
10
is a group CH
3
SO
2
attached to the benzoyl group at the 4-position.
The most preferred compounds of Formula (IA) are 2-(2-chloro-4-methanesulphonylbenzoyl)-1,3-cyclohexanedione and 2-(2-nitro-4-methanesulphonylbenzoyl)-1,3-cyclohexanedione
Another class of compounds of formula (I) are compounds of formula (IB)
where Q is as defined in relation to Formula (I) and R
y
is C3-6 cycloalkyl optionally substituted by one more groups R
z
where R
z
is as defined for R
7
above. A preferred group R
y
is optionally substituted cyclopropyl. A preferred compound of Formula (IB) is trinexepac ethyl (ethyl 4-cyclopropyl(hydroxy)methylene-3,5-dioxocyclohexanedionecarboxylate).
Preferred azoles are compounds of Formula (III)
in which A is N or CR
22
; B is N or CR
23
; R
21
, R
22
and R
23
are independently H, alkyl, or aryl or when B is CR
23
, R
21
, and R
23
together with the carbon atoms to which they are attached form a 6-membered carbocyclic ring; and salts thereof
A is preferably N or CH.
Preferably B is N and R
21
is H or B is CR
23
and R
21
and R
23
together with the carbon atoms to which they are attached form a 6-membered unsaturated carbocyclic ring.
Particularly preferred compounds of Formula (III) are 1H-1,2,4-triazole and 1H-1,2,3-benzotriazole.
Suitable salts of azoles may be for example the potassium salt or the tetrab

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