WO2000069800A2 - Process for preparing ketones or aldehydes - Google Patents
Process for preparing ketones or aldehydes Download PDFInfo
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- WO2000069800A2 WO2000069800A2 PCT/EP2000/004594 EP0004594W WO0069800A2 WO 2000069800 A2 WO2000069800 A2 WO 2000069800A2 EP 0004594 W EP0004594 W EP 0004594W WO 0069800 A2 WO0069800 A2 WO 0069800A2
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- formula
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- process according
- substituted
- nitro
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- 0 C*C(*)(*)[N+]([O-])=O Chemical compound C*C(*)(*)[N+]([O-])=O 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
- C07C201/06—Preparation of nitro compounds
- C07C201/12—Preparation of nitro compounds by reactions not involving the formation of nitro groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C319/00—Preparation of thiols, sulfides, hydropolysulfides or polysulfides
- C07C319/14—Preparation of thiols, sulfides, hydropolysulfides or polysulfides of sulfides
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/51—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition
- C07C45/516—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of nitrogen-containing compounds to >C = O groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D261/00—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings
- C07D261/02—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings not condensed with other rings
- C07D261/06—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings not condensed with other rings having two or more double bonds between ring members or between ring members and non-ring members
- C07D261/08—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings not condensed with other rings having two or more double bonds between ring members or between ring members and non-ring members with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
Definitions
- This invention relates to a process for preparing alkyl and aromatic ketones or aldehydes. More particularly the invention relates to a process for the preparation of aromatic ketone intermediates used in the manufacture of pesticides.
- Pesticidal 4-benzoylisoxazoles particularly 5- cyclopropylisoxazole herbicides and intermediate compounds in their synthesis, are described in the literature, for example in European Patent Publication Nos. 0418175, 0487353, 0527036, 0560482, 0609798 and 0682659.
- Aromatic ketones are important intermediates for a number of valuable compounds including pesticides, particularly the 4- benzoylisoxazole derivatives referred to above.
- Nef reactions are classically performed by the conversion of a nitro compound into the nitronate salt using a base, followed by the key step which is acidification with an aqueous acid to yield the carbonyl compound. However these conditions frequently give poor yields when applied to the preparation of aromatic ketones.
- the oxidative Nef reaction proceeds similarly with conversion of the nitro compound into the nitronate salt using a base, followed by an oxidation to give the carbonyl compound.
- Numerous oxidants have been employed in the oxidative Nef reaction, including excess hydrogen peroxide, as described by Olah et.al., Synthesis 662 (1980), potassium permanganate (Reid et al. Tetrahedron Letters 32, 1093 (1990)), ammonium or sodium persulphate (Pagano et al., J.Org.Chem.
- WO9855437 describes a catalysed Nef oxidation using hydrogen peroxide under basic conditions.
- the oxidative Nef reaction has also been performed using molecular oxygen (air), however only in the presence of a base such as aqueous sodium hydroxide or potassium ethoxide (J.T.Thurston et al., J.Am.Chem.Soc. 57, 2163 (1935), or G.A.Russel, J.Am.Chem.Soc. 1595 (1954), or Y.Yano et al., J.Chem.Soc.Chem.Commun. 695
- nitro compounds are first converted into the nitronate salt which is then oxidized with oxygen to give the carbonyl compound.
- the reductive Nef reaction is less well known and a number of reagents have been found to convert nitro compounds into the corresponding aldehydes or ketones, such as ⁇ CI3, VCI2, CrCl2 or ascorbic acid, generally via oxime intermediates.
- the present invention accordingly provides a process for the preparation of a compound of formula (I):
- R " l and R ⁇ which may be the same or different, each represent hydrogen, unsubstituted or substituted C1-C6 alkyl, unsubstituted or substituted C3-C7 cycloalkyl, unsubstituted or substituted 5-7 membered ring aryl, or unsubstituted or substituted 5-7 membered ring heteroaryl which contains one to four hetero atoms selected from O,N and S; or
- R! and R ⁇ together with the carbon atom to which they are attached represent unsubstituted or substituted C3-C7 cycloalkyl; which process comprises the direct oxidation of a nitro compound of formula
- Alkyl groups may be straight or branched-chain, preferably C1-C3 alkyl.
- the aryl ring is selected from phenyl and naphthyl, and preferably the heteroaryl ring is selected from pyridyl, thienyl, furyl and pyrrolyl.
- the substituted alkyl group may have as substitutents one or more groups selected from substituted aryl, substituted heteroaryl, Cl- C6 alkoxy, halogen, nitro and -S(O) m R 3 wherein R 3 is C1-C6 alkyl or
- Cycloalkyl groups may be substituted by one or more C1-C6 alkyl groups or halogen atoms.
- Aryl or heteroaryl groups may be substituted by one or more groups selected from halogen, R 3 , C1-C6 alkoxy, C1-C6 haloalkoxy, -S(O) m R 3 , cycloalkyl having from 3 to 7 ring carbon atoms, C2-C6 alkenyl or C2-C6 alkynyl, NO2 and
- R5 independently represent hydrogen, Cl-C6alkyl or C1-C6 haloalkyl.
- the reaction to prepare a compound of formula (I) from a compound of formula (II) is generally performed in a solvent such as aprotic solvents for example dimethylsulphoxide, N,N- dimethylformamide, N-methylpyrrolidone, sulpholane, or aromatic hydrocarbons such as toluene or xylene, or alcohols such as methanol or ethanol, or aliphatic hydrocarbons such as hexane or cyclohexane, optionally in the presence of water or an aqueous acid such as acetic acid, in the presence of air.
- Preferred solvents include dimethylsulphoxide, N,N-dimethylformamide, N-methylpyrrolidone and sulpholane (dimethylsulphoxide and N,N-dimethylformamide are more preferred).
- the reaction is performed without the need for base and hence the nitro compound of formula (II) is not present as the nitronate salt.
- the reaction temperature is generally from 20 to 120°C, preferably from 50 to 100°C.
- a preferred embodiment of the invention provides a process (A) for the preparation of a compound of formula (III):
- R 6 is halogen, R 3 , C1-C6 alkoxy, C1-C6 haloalkoxy, -S(O) m R 3 , cycloalkyl having from 3 to 7 ring carbon atoms, C2-C6 alkenyl or C2- C6 alkynyl, or -(CR R 5 ) q -S(O) p R 3 wherein p is 0,1 or 2 and q is 1 or 2; R 3 is C 1 -C6 alkyl or C 1 -C6 haloalkyl; and R 4 and R 5 independently represent hydrogen, Cl-C6alkyl or C1-C6 haloalkyl; and n is zero or an integer from one to three; which process comprises the direct oxidation of a nitro compound of formula (IV):
- reaction conditions which are suitable are the same as those used for the preparation of a compound of formula (I) from a compound of formula (II).
- the group -NO2 in the phenyl ring of formula (IV) is located at the 2- or 4- position relative to the nitroethyl group, most preferably at the 2- position of the phenyl ring.
- R ⁇ represents C1-C3 haloalkyl (most preferably trifluoromethyl).
- a most preferred compound of formula (IV) is 3-nitro-4-(l- nitroethyl)benzotrifluoride .
- a particular advantage of the invention is that the combined processes (A) and (B) may be performed in a single pot to convert a compound of formula (V) into a compound of formula (III) without the need to isolate and purify the intermediate compound of formula (IV).
- an acid generally an aqueous acid
- an acid which may be a mineral acid such as hydrochloric acid or sulphuric acid but is preferably a weak acid such as acetic acid, formic acid or oxalic acid (more preferably acetic acid) to give a neutral or acidic mixture (generally the pH of the mixture is from 3-5), prior to the in situ oxidation step (A).
- a solvent such as toluene may optionally be added at the same time as the acid is added.
- the above process (A), or the combined processes (A) and (B), can be combined with an additional process step (C), which comprises the reaction of a compound of formula (III) as defined above with a compound of formula (VI):
- R ⁇ , R? and n are as defined above and R a is C1-C6 alkyl.
- Example 3 The procedure of Example 1 was repeated but using N,N- dimethylformamide as solvent and heating at 60°C under air atmosphere for 8 hours at 60°C after which time the starting material was completely consumed, to give the title compound in 70% yield.
- Example 3 The procedure of Example 1 was repeated but using N,N- dimethylformamide as solvent and heating at 60°C under air atmosphere for 8 hours at 60°C after which time the starting material was completely consumed, to give the title compound in 70% yield.
- Example 1 was repeated but the mixture was heated under a nitrogen atmosphere. After 5 hours at 60°C the conversion of 3-nitro-4- (l-nitroethyl)be-nzotrifluoride was ⁇ 10% and did not increase further with a prolonged reaction time. This result illustrates that the presence of air is critical to the success of the oxidation.
Abstract
The invention relates to a process for preparing compounds of formula (I), wherein R?1 and R2¿ are as defined in the description.
Description
PROCESS
This invention relates to a process for preparing alkyl and aromatic ketones or aldehydes. More particularly the invention relates to a process for the preparation of aromatic ketone intermediates used in the manufacture of pesticides.
Pesticidal 4-benzoylisoxazoles, particularly 5- cyclopropylisoxazole herbicides and intermediate compounds in their synthesis, are described in the literature, for example in European Patent Publication Nos. 0418175, 0487353, 0527036, 0560482, 0609798 and 0682659.
Various methods for preparing these compounds are known. It is an object of the present invention to provide improved methods for the preparation of these compounds and the intermediate compounds thereto. A further object of the present invention is to provide a process which is efficient and simple to perform, and which does not require the use of a base or expensive reagents. Description of the Related Art
Aromatic ketones are important intermediates for a number of valuable compounds including pesticides, particularly the 4- benzoylisoxazole derivatives referred to above.
Conversion of primary or secondary nitro compounds into the corresponding carbonyl compounds can be achieved using the Nef reaction which is well known in the art. Nef reactions are classically performed by the conversion of a nitro compound into the nitronate salt using a base, followed by the key step which is acidification with an aqueous acid to yield the carbonyl compound. However these conditions frequently give poor yields when applied to the preparation of aromatic ketones.
The oxidative Nef reaction proceeds similarly with conversion of the nitro compound into the nitronate salt using a base, followed by an oxidation to give the carbonyl compound. Numerous oxidants have been employed in the oxidative Nef reaction, including excess hydrogen
peroxide, as described by Olah et.al., Synthesis 662 (1980), potassium permanganate (Reid et al. Tetrahedron Letters 32, 1093 (1990)), ammonium or sodium persulphate (Pagano et al., J.Org.Chem. 35, 295 (1970)), t-butyl hydroperoxide with vanadyl acetylacetonate (VO(AcAc)2) (Bartlett et al., Tetrahedron Letters 4, 331 (1977)), ozone
(J.Org.Chem. 39, 259 (1974)) and singlet oxygen in the presence of a base (J.Org.Chem. 43, 1271 (1978)). However these methods have the disadvantage of being uneconomic, potentially hazardous or give poor yields. In addition to the above, WO9855437 describes a catalysed Nef oxidation using hydrogen peroxide under basic conditions.
The oxidative Nef reaction has also been performed using molecular oxygen (air), however only in the presence of a base such as aqueous sodium hydroxide or potassium ethoxide (J.T.Thurston et al., J.Am.Chem.Soc. 57, 2163 (1935), or G.A.Russel, J.Am.Chem.Soc. 1595 (1954), or Y.Yano et al., J.Chem.Soc.Chem.Commun. 695
(1984)). In all of these examples the nitro compounds are first converted into the nitronate salt which is then oxidized with oxygen to give the carbonyl compound.
The reductive Nef reaction is less well known and a number of reagents have been found to convert nitro compounds into the corresponding aldehydes or ketones, such as ΗCI3, VCI2, CrCl2 or ascorbic acid, generally via oxime intermediates.
It has now been unexpectedly discovered that the direct oxidation of nitro compounds into ketones may be performed without the need to convert to the nitronate salts using basic medium. This procedure has not been previously reported.
Summary of the Invention
The present invention accordingly provides a process for the preparation of a compound of formula (I):
O
1
(I) wherein R"l and R^, which may be the same or different, each represent hydrogen, unsubstituted or substituted C1-C6 alkyl, unsubstituted or substituted C3-C7 cycloalkyl, unsubstituted or substituted 5-7 membered ring aryl, or unsubstituted or substituted 5-7 membered ring heteroaryl which contains one to four hetero atoms selected from O,N and S; or
R! and R^ together with the carbon atom to which they are attached represent unsubstituted or substituted C3-C7 cycloalkyl; which process comprises the direct oxidation of a nitro compound of formula
(II):
(II) wherein R! and R^ are as defined above. Alkyl groups may be straight or branched-chain, preferably C1-C3 alkyl. Preferably the aryl ring is selected from phenyl and naphthyl, and preferably the heteroaryl ring is selected from pyridyl, thienyl, furyl and pyrrolyl. The substituted alkyl group may have as substitutents one or more groups selected from substituted aryl, substituted heteroaryl, Cl- C6 alkoxy, halogen, nitro and -S(O)mR3 wherein R3 is C1-C6 alkyl or
C1-C6 haloalkyl. Cycloalkyl groups may be substituted by one or more C1-C6 alkyl groups or halogen atoms. Aryl or heteroaryl groups may be substituted by one or more groups selected from halogen, R3, C1-C6 alkoxy, C1-C6 haloalkoxy, -S(O)mR3, cycloalkyl having from 3 to 7 ring carbon atoms, C2-C6 alkenyl or C2-C6 alkynyl, NO2 and
-(CR4R5)q-S(O)pR3 wherein p is 0,1 or 2 and q is 1 or 2; and R4 and
R5 independently represent hydrogen, Cl-C6alkyl or C1-C6 haloalkyl.
The reaction to prepare a compound of formula (I) from a compound of formula (II) is generally performed in a solvent such as aprotic solvents for example dimethylsulphoxide, N,N- dimethylformamide, N-methylpyrrolidone, sulpholane, or aromatic hydrocarbons such as toluene or xylene, or alcohols such as methanol or ethanol, or aliphatic hydrocarbons such as hexane or cyclohexane, optionally in the presence of water or an aqueous acid such as acetic acid, in the presence of air. Preferred solvents include dimethylsulphoxide, N,N-dimethylformamide, N-methylpyrrolidone and sulpholane (dimethylsulphoxide and N,N-dimethylformamide are more preferred).
The reaction is performed without the need for base and hence the nitro compound of formula (II) is not present as the nitronate salt. The reaction temperature is generally from 20 to 120°C, preferably from 50 to 100°C.
A preferred embodiment of the invention provides a process (A) for the preparation of a compound of formula (III):
R6 is halogen, R3, C1-C6 alkoxy, C1-C6 haloalkoxy, -S(O)mR3, cycloalkyl having from 3 to 7 ring carbon atoms, C2-C6 alkenyl or C2- C6 alkynyl, or -(CR R5)q-S(O)pR3 wherein p is 0,1 or 2 and q is 1 or 2; R3 is C 1 -C6 alkyl or C 1 -C6 haloalkyl; and R4 and R5 independently represent hydrogen, Cl-C6alkyl or C1-C6 haloalkyl; and n is zero or an integer from one to three; which process comprises the direct oxidation of a nitro compound of formula (IV):
(IV) wherein R^ and n are as defined above.
The reaction conditions which are suitable are the same as those used for the preparation of a compound of formula (I) from a compound of formula (II).
Preferably the group -NO2 in the phenyl ring of formula (IV) is located at the 2- or 4- position relative to the nitroethyl group, most preferably at the 2- position of the phenyl ring. Preferably R^ represents C1-C3 haloalkyl (most preferably trifluoromethyl).
A most preferred compound of formula (IV) is 3-nitro-4-(l- nitroethyl)benzotrifluoride .
According to a further feature of the present invention the above process (A) can be combined with an additional process step (B), which comprises the reaction of a compound of formula (V):
(V) wherein R° and n are as defined above, and X represents halogen preferably chlorine or fluorine; with nitroethane and a base in a solvent to give a compound of formula (IV) as defined above. The base used is generally an alkali metal hydroxide such as potassium hydroxide, and the solvent is generally an aprotic solvent such as dimethylsulphoxide. A most preferred compound of formula (V) is 4-chloro-3-
nitrobenzotrifluoride. Preferably the group -NO2 in the phenyl ring of formula (V) is located at the 2- or 4- position relative to the group X, most preferably at the 2- position of the phenyl ring.
A particular advantage of the invention is that the combined processes (A) and (B) may be performed in a single pot to convert a compound of formula (V) into a compound of formula (III) without the need to isolate and purify the intermediate compound of formula (IV). When the above single pot procedure is employed, the reaction mixture from the first process (B) which contains the compound of formula (IV) is treated with an acid (generally an aqueous acid) which may be a mineral acid such as hydrochloric acid or sulphuric acid but is preferably a weak acid such as acetic acid, formic acid or oxalic acid (more preferably acetic acid) to give a neutral or acidic mixture (generally the pH of the mixture is from 3-5), prior to the in situ oxidation step (A). A solvent such as toluene may optionally be added at the same time as the acid is added.
Compounds of formula (IV) and (V) are known or may be prepared by known methods.
According to a further feature of the present invention the above process (A), or the combined processes (A) and (B), can be combined with an additional process step (C), which comprises the reaction of a compound of formula (III) as defined above with a compound of formula (VI):
R7SH (VI) wherein R represents C1-C6 alkyl (preferably methyl), to give a compound of formula (VII):
(VII)
wherein R°, R7 and n are as defined above. The reaction of a compound of formula (III) with a compound of formula (VI) is generally performed in the presence of a base and solvent, and is generally known, and may be performed without isolation of the compounds of formula (IV) or (III).
The above compounds of formula (VII) may be used for the preparation of herbicidally active 4-benzoylisoxazole derivatives, for example according to the following reaction scheme :-
The following non-limiting examples illustrate the invention. Example 1
Preparation of 2-nitro-4-trifluoromethylacetophenone from 3- nitro-4-(l-nitroethyl)benzotrifluoride
A solution of 3-nitro-4-(l-nitroethyl)benzotrifluoride (0.25 g) in dimethylsulphoxide (5 ml) was vigorously stirred and heated to 60°C under an air atmosphere. After 5 hours at 60°C the starting material was completely consumed and an 80% yield of 2-nitro-4-trifluoromethyl- acetophenone was obtained.
Example 2
Preparation of 2-nitro-4-trifluoromethylacetophenone from 3- nitro-4-(l-nitrσethyl)benzotrifluoride
The procedure of Example 1 was repeated but using N,N- dimethylformamide as solvent and heating at 60°C under air atmosphere for 8 hours at 60°C after which time the starting material was completely consumed, to give the title compound in 70% yield. Example 3
Preparation of 2-nitro-4-trifluoromethylacetophenone from 4- chloro-3-nitrobenzotrifluoride via 3-nitro-4-(l- nitroethyI)benzotrifluoride by a single pot method
Potassium hydroxide (2.027 g) and nitroethane (1.442 g) were added to dimethylsulphoxide (28 ml) with vigorous stirring. The mixture was then cooled to 15°C and 4-chloro-3-nitrobenzotrifluoride (3.144 g) added over 45 minutes maintaining between 15 and 20°C, and allowed to warm to 20-25°C over 3 hours, after which time analysis indicated >99% consumption of 4-chloro-3- nitrobenzotrifluoride.Toluene (40 ml) was then added and the reaction mixture cooled to 10°C, then aqueous acetic acid (3.4N ; 11.3 g) was added dropwise under vigorous stirring to bring the mixture to pH3-5 and transform the nitronate into the nitro compound. The reaction mixture was then heated to 60°C for 5 hours under an air atmosphere, after which time the 3-nitro-4-(l-nitroethyl)benzotrifluoride was completely consumed. The aqueous layer was extracted with toluene and the combined organic layer washed with water, dried (MgSO4) and evaporated to afford 3.155g of a red oil which was 80% pure by Η
NMR. Quantitative GC analysis indicated 75% purity for 2-nitro-4- trifluoromethylacetophenone (yield=74 %); Η NMR (CDC13) δ 8.30 (s, 1H) ; 7.92 (dd, 1H) ; 7.52 (d, 1H) ; 2.51 (s, 3H).
The above procedure was repeated but the mixture was heated to 70°C for 4 hours under an air atmosphere, after which time the 3-nitro-
4-(l-nitroethyl)benzotrifluoride was completely consumed, to afford 2- nitro-4-trifluoromethylacetophenone (3.18 g) as a red oil (yield=65 %).
The above procedure was repeated but the mixture was heated to 50°C for 9 hours under an air atmosphere, after which time the 3-nitro- 4-(l-nitroethyl)benzotrifluoride was completely consumed, to afford 2- nitro-4-trifluoromethylacetophenone (3.248 g) as an orange oil (yield=78 %).
Reference Example 1
Preparation of 3-nitro-4-(l-nitroethyl)benzotrifluoride from 4- chloro-3-nitrobenzotrifluoride
Potassium hydroxide (3.924 g) and nitroethane (3.12 g) were added to dimethylsulphoxide (60 ml) with vigorous stirring. The mixture was then cooled to 15°C and 4-chloro-3-nitrobenzotrifluoride (4.664 g) added over 45 minutes maintaining between 15 and 20°C, and allowed to warm to 20-25°C over 3 hours, when GC analysis indicated > 99% consumption of 4-chloro-3-nitrobenzotrifluoride. Aqueous hydrochloric acid (IN ; 34 g) was added dropwise maintaining below
25°C with vigorous stirring to transform the nitronate into the nitro compound. After extraction with ethyl acetate the organic solution was dried (MgSO4) and concentrated to afford 3-nitro-4-(l- nitroethyl)benzotrifluoride (5.4 g) as a red oil (yield=90%). Comparative Example 1 :
Example 1 was repeated but the mixture was heated under a nitrogen atmosphere. After 5 hours at 60°C the conversion of 3-nitro-4- (l-nitroethyl)be-nzotrifluoride was < 10% and did not increase further with a prolonged reaction time. This result illustrates that the presence of air is critical to the success of the oxidation.
Claims
1. A process for the preparation of a compound of formula (I):
O
I
R1^^R2
(I) wherein R and R^, which may be the same or different, each represent hydrogen, unsubstituted or substituted C1-C6 alkyl, unsubstituted or substituted C3-C7 cycloalkyl, unsubstituted or substituted 5-7 membered ring aryl, or unsubstituted or substituted 5-7 membered ring heteroaryl which contains one to four hetero atoms selected from O,N and S; or
R! and R2 together with the carbon atom to which they are attached represent unsubstituted or substituted C3-C7 cycloalkyl; which process comprises the direct oxidation of a nitro compound of formula
(II):
H NO2 V Rl-^R
(II) wherein R and R^ are as defined above.
2. A process according to claim 1 wherein the reaction is performed in an aprotic solvent in the presence of air.
3. A process according to claim 1 or 2 in which the solvent is selected from dimethylsulphoxide, N,N-dimethylformamide, N-methylpyrrolidone and sulpholane.
4. A process according to claim 1 , 2 or 3 in which a compound of formula (III): 
(in) wherein:
R6 is halogen, R3, C1-C6 alkoxy, C1-C6 haloalkoxy, -S(O)mR3, cycloalkyl having from 3 to 7 ring carbon atoms, C2-C6 alkenyl or C2- C6 alkynyl, or -(CR4R5)q-S(O)pR3 wherein p is 0,1 or 2 and q is 1 or 2;
R3 is C1-C6 alkyl or C1-C6 haloalkyl; and R4 and R5 independently represent hydrogen, C1-C6 alkyl or C1-C6 haloalkyl; and n is zero or an integer from one to three; is prepared from a nitro compound of formula (IV):
(IV) wherein R" and n are as defined above.
5. A process according to claim 4 in which the compound of formula (IV) is prepared by the reaction of a compound of formula (V):
(V) wherein R° and n are as defined in claim 4, and X represents halogen preferably chlorine or fluorine; with nitroethane and a base.
6. A process according to claim 4 or 5, in which further comprises the reaction of a compound of formula (III) with a compound of formula (VI):
R7SH (VI) wherein R7 represents C1-C6 alkyl, to prepare a compound of formula (VII):
(VII) wherein R^ and n are as defined in claim 4.
7. A process according to any one of claims 2 to 6 in which the -NO2 group in the phenyl ring of formula (IV) is located at the 2- position relative to the nitroethyl group.
8. A process according to any one of claims 2 to 7 in which R? represents trifluoromethyl.
9. A process according to any one of claims 2 -8 in which R7 represents methyl.
10. A process according to any one of the preceding claims which further comprises converting a compound of formula (I) into a pesticidal 4-benzoylisoxazole compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU56750/00A AU5675000A (en) | 1999-05-13 | 2000-05-11 | Process |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9911181A GB9911181D0 (en) | 1999-05-13 | 1999-05-13 | Process |
| GB9911181.7 | 1999-05-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO2000069800A2 true WO2000069800A2 (en) | 2000-11-23 |
| WO2000069800A3 WO2000069800A3 (en) | 2001-03-29 |
Family
ID=10853437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2000/004594 WO2000069800A2 (en) | 1999-05-13 | 2000-05-11 | Process for preparing ketones or aldehydes |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU5675000A (en) |
| GB (1) | GB9911181D0 (en) |
| WO (1) | WO2000069800A2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE859009C (en) * | 1944-02-26 | 1952-12-11 | Basf Ag | Process for the production of ketones |
| EP0527036A1 (en) * | 1991-08-05 | 1993-02-10 | Rhone-Poulenc Agriculture Ltd. | 4-Benzoylisoxazole derivatives and their use as herbicides |
| WO1997028122A2 (en) * | 1996-02-01 | 1997-08-07 | Rhone-Poulenc Agrochimie | Process for preparing diketone compounds |
| WO1998055437A1 (en) * | 1997-06-03 | 1998-12-10 | Eastman Chemical Company | Catalyst for oxidative nef reaction using basic hydrogen peroxide |
| WO1998055446A1 (en) * | 1997-06-03 | 1998-12-10 | Eastman Chemical Company | Process for the preparation of thioether-substituted aromatic ketones |
-
1999
- 1999-05-13 GB GB9911181A patent/GB9911181D0/en not_active Ceased
-
2000
- 2000-05-11 WO PCT/EP2000/004594 patent/WO2000069800A2/en active Application Filing
- 2000-05-11 AU AU56750/00A patent/AU5675000A/en not_active Abandoned
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE859009C (en) * | 1944-02-26 | 1952-12-11 | Basf Ag | Process for the production of ketones |
| EP0527036A1 (en) * | 1991-08-05 | 1993-02-10 | Rhone-Poulenc Agriculture Ltd. | 4-Benzoylisoxazole derivatives and their use as herbicides |
| WO1997028122A2 (en) * | 1996-02-01 | 1997-08-07 | Rhone-Poulenc Agrochimie | Process for preparing diketone compounds |
| WO1998055437A1 (en) * | 1997-06-03 | 1998-12-10 | Eastman Chemical Company | Catalyst for oxidative nef reaction using basic hydrogen peroxide |
| WO1998055446A1 (en) * | 1997-06-03 | 1998-12-10 | Eastman Chemical Company | Process for the preparation of thioether-substituted aromatic ketones |
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Also Published As
| Publication number | Publication date |
|---|---|
| WO2000069800A3 (en) | 2001-03-29 |
| GB9911181D0 (en) | 1999-07-14 |
| AU5675000A (en) | 2000-12-05 |
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