The present invention relates to a novel process for preparing 2,5-bisaryl-Δ1-pyrrolines.
Δ1-Pyrrolines, processes for their preparation and their use as pesticides are already described in WO 00/21958, WO 99/59968, WO 99/59967 and WO 98/22438. However, in terms of yield, practice of the reaction, the number of byproducts, the kind of work-up, the amount of waste produced and the energy requirements, these processes are unsatisfactory. Accordingly, there is a constant need for novel processes which overcome one or more of the disadvantages mentioned.
It has now been found that 2,5-bisaryl-Δ1-pyrrolines of the formula (I)
in which
in which
Ar1 and Ar2 are as defined above
with an acid, if appropriate in the presence of a diluent.
It is extremely surprising that 2,5-bisaryl-Δ1-pyrrolines of the formula (I) can be prepared by the process according to the invention in a smooth reaction without interfering side reactions, in high yields and with high purity.
The process according to the invention is characterized by the following further advantage. Owing to the course of the reaction, the pyrrolines formed are obtained as only one double bond isomer with respect to the double bond in the pyrroline ring. The double bond in the ring is always located between the nitrogen atom and the carbon atom to which Ar1 is attached. A possible shift of the C═C double bond has not been observed under the conditions of the process according to the invention.
Using tert-butyl 3-(2-bromobenzoyl)-2-oxo-5-[4-(trifluoromethoxy)phenyl]-1-pyrrolidinecarboxylate as starting material and sulfuric acid, the course of the process according to the invention can be illustrated by the formula scheme below.
The formula (II) provides a general definition of the amides required as starting materials for carrying out the process according to the invention.
Preferred substituents or ranges in the formulae of starting materials of the formula (II) shown above and below are illustrated below.
Particularly preferred starting materials for the process according to the invention are the compounds of the formula (II-a)
in which
Very particular preference is given to starting materials of the formula (II-a) in which
Especially preferred are starting materials of the formula (II-a) in which
Starting materials for the process according to the invention which are likewise emphasized are the compounds of the formula (II-b)
in which
Starting materials for the process according to the invention which are likewise emphasized are the compounds of the formula (II-c)
in which
Preference is given to compounds of the formulae (II-b) and (II-c), in which Ar2, R1, R2 and R3 have the meanings given above as being preferred for these radicals.
Particular preference is given to compounds of the formulae (II-b) and (II-c) in which Ar2, R1, R2 and R3 have the meanings given above as being particularly preferred for these radicals.
Very particular preference is given to the compounds of the formulae (II-b) and (II-c) in which Ar2, R1, R2 and R3 have the meanings given above as being very particularly preferred for these radicals.
Starting materials for the process according to the invention which are likewise emphasized are the compounds of the formula (II-d)
in which
Ar1, R4, R5 and m are as defined above.
Starting materials for the process according to the invention which are likewise emphasized are the compounds of the formula (II-e)
in which
Ar1, R4, R5 and m are as defined above.
Preference is given to compounds of the formulae (II-d) and (II-e), in which R1, R2, R3 and Ar2 have the meanings given above as being preferred for these radicals.
Particular preference is given to the compounds of the formulae (II-d) and (II-e), in which R1, R2, R3 and Ar2 have the meanings given above as being particularly preferred for these radicals.
Very particular preference is given to the compounds of the formulae (II-d) and (II-e) in which R1, R2, R3 and Ar2 have the meanings given above as being very particularly preferred for these radicals.
Particularly preferred starting materials for the process according to the invention are the compounds of the formula (II-f)
in which
Very particular preference is given to starting materials of the formula (II-f) in which
Especially preferred are starting materials of the formula (II-f) in which
Particularly preferred starting materials for the process according to the invention are the compounds of the formula (II-g)
in which
Very particular preference is given to starting materials of the formula (II-g) in which
Especially preferred are starting materials of the formula (II-g) in which
In the definitions mentioned above, oxyalkylene and thioalkylene represent —O-alkyl- and —S-alkyl-, respectively, where the bond for example to Ar2 is via the oxygen and sulfur atom, respectively, and further substituents may be attached to the alkyl radical, such as, for example, A in —X—A. Alkylenoxy and alkylenethio represent -alkyl-O— and -alkyl-S—, respectively, where the bond for example to Ar2 is in each case via the alkyl radical and further substituents may be attached to the oxygen and sulfur atom, respectively, such as, for example, A in —X—A. Oxyalkylenoxy represents —O-alkyl-O—.
In the present description, heterocyclyl denotes a cyclic hydrocarbon in which one or more carbons are replaced by one or more heteroatoms. Preferred heteroatoms are O, S, N, P, in particular O, S and N.
Preferred, particularly preferred or very particularly preferred are compounds which carry the substituents mentioned under preferred, particularly preferred or very particularly preferred.
Saturated or unsaturated hydrocarbon radicals, such as alkyl or alkenyl, can in each case be straight-chain or branched as far as this is possible, including in combination with heteroatoms, such as, for example, in alkoxy.
Optionally substituted radicals can be mono- or polysubstituted, where in the case of polysubstitution the substituents can be identical or different. The plurality of radicals having the same indices, such as, for example, m radicals R5 for m >1, can be identical or different.
Halogen-substituted radicals, such as, for example, haloalkyl, are mono- or polyhalogenated. In the case of polyhalogenation, the halogen atoms can be identical or different. Halogen denotes fluorine, chlorine, bromine or iodine, in particular fluorine or chlorine.
However, the abovementioned general or preferred radical definitions or illustrations can also be combined with one another as desired, i.e. including combinations between the respective ranges and preferred ranges. They apply both to the end products and, correspondingly, to precursors and intermediates.
The aroylpyrrolidinones of the formula (II) required as starting materials for carrying out the process according to the invention are novel. They can be prepared by
The formula (III) provides a general definition of the lactams required as starting materials for carrying out the process (a) according to the invention. In this formula, Ar2 preferably, particularly preferably or very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals.
Lactams of the formula (III) are known. They can be prepared, for example, by
The formula (IV) provides a general definition of the compounds required as starting materials for carrying out the process (a) according to the invention. In this formula, Ar1 preferably, particularly preferably or very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals. G preferably represents chlorine, methoxycarbonyl, ethoxycarbonyl, i-propoxycarbonyl, t-butoxycarbonyl or —N(OCH3)CH3.
Compounds of the formula (IV) are known and/or can be prepared by known processes (cf. J. Prakt. Chem. 2000, 342, 340).
The formula (V) provides a general definition of the pyrrolidinones required as starting materials for carrying out the process (b) according to the invention. In this formula, Ar2 preferably, particularly preferably or very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals.
Pyrrolidinones of the formula (V) are known. They can be prepared, for example, by
The formula (VI) provides a general definition of the ketocarboxylic acids required as starting materials for carrying out the process (c) according to the invention. In this formula, Ar2 preferably, particularly preferably and very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals.
Ketocarboxylic acids of the formula (VI) are known. They can be prepared, for example, by
The formula (VII) provides a general definition of the hemi-aminals required as starting materials for carrying out the processes (d) and (e) according to the invention. In this formula, R9 preferably represents C1-C6-alkyl or C1-C4-alkylcarbonyl. R9 particularly preferably represents C1-C4-alkyl, methylcarbonyl or t-butylcarbonyl. R9 very particularly preferably represents methyl, ethyl, i-propyl, t-butyl or methylcarbonyl.
Hemi-aminals of the formula (VII) are known and/or can be prepared by the known processes (cf. Tetrahedron 1975, 31, 1437; Heterocycles 1983, 20, 985).
The formula (VIII) provides a general definition of the aromatic compounds required as starting materials for carrying out the processes (d) and (f) according to the invention. In this formula, Ar2 preferably, particularly preferably and very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals.
Aromatic compounds of the formula (VIII) are known.
The formula (IX) provides a general definition of the metalloaromatic compounds required as starting materials for carrying out the process (e) according to the invention. In this formula, Ar2 preferably, particularly preferably and very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals. M preferably represents MgI, MgCl, MgBr, Li or ZnCl. M particularly preferably represents MgI, MgCl, MgBr or Li. M very particularly preferably represents MgCl, MgBr or Li.
Metalloaromatic compounds of the formula (IX) are known and/or can be prepared by known methods (for example lithiation or Grignard reaction) from the corresponding aromatic compounds or halogenated aromatic compounds.
The formula (X) provides a general definition of the carbonyl compounds required as starting materials for carrying out the process (h) according to the invention. In this formula, Ar2 preferably, particularly preferably and very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals.
Carbonyl compounds of the formula (X) are known. They can be prepared, for example, by
The formula (XI) provides a general definition of the acetophenones required as starting materials for carrying out the process (i) according to the invention. In this formula, Ar2 preferably, particularly preferably and very particularly preferably has those meanings which have already been mentioned in connection with the description of the starting materials of the formula (II) as being preferred, particularly preferred, etc., for these radicals.
Acetophenones of the formula (XI) are known.
The process according to the invention is carried out in the presence of an acid. Suitable acids for carrying out the process according to the invention are all customary protic acids or strong organic acids (such as, for example, sulfonic acids) or halocarboxylic acids which can be used for such reaction. Preference is given to using hydrochloric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoroacetic acid or trichloroacetic acid.
Particular preference is given to using hydrochloric acid, sulfuric acid p-toluenesulfonic acid or trifluoroacetic acid, very particularly preferably sulfuric acid. If appropriate, the acid used can be employed in a mixture with water. If appropriate, the process according to the invention can be carried out in the presence of a diluent. Suitable diluents for carrying out the process according to the invention are organic acids. Preference is given to using propionic acid, acetic acid or formic acid. Particular preference is given to using acetic acid.
When carrying out the process according to the invention, very particular preference is given to using any mixture of sulfuric acid (as acid) and acetic acid (as diluent) and, if appropriate, water. Particularly suitable is a mixture of concentrated sulfuric acid, water and acetic acid in a ratio of 1:1:2 (volume/volume/volume=v/v/v) or 1:1:3 (v/v/v). However, it is also possible to adjust and employ other mixing ratios.
When carrying out the process according to the invention, the reaction temperatures can be varied within a relatively wide range. In general, the process is carried out at temperatures between 20° C. and 200° C., preferably at temperatures between 60° C. and 150° C.
Expediently, the course of the reaction is monitored by thin-layer chromatography. Depending on the nature of the compound of the formula (II) employed, the reaction time is between 0.5 h and 6 h.
When carrying out the process according to the invention, in general an excess of acid (between 1 mol and 50 mol) is employed per mole of aroylpyrrolidinone of the formula (II). However, it is also possible to choose other ratios of the reaction components. Work-up is carried out by customary methods. In general, the reaction mixture is made alkaline with sodium hydroxide, the product is extracted and the organic phase is washed, dried and concentrated under reduced pressure. The crude product is then freed of any residues that may still be present using customary methods (for example chromatography or recrystallization).
Some of the 2,5-bisaryl-Δ1-pyrrolines of the formula (I), which can be prepared by the process according to the invention are known. Also known is their use for controlling pests. They are particularly suitable for controlling insects, arachnids and nematodes encountered in agriculture, in forests, in the protection of stored products and materials and in the hygiene sector (see WO 00/21958, WO 99/59968, WO 99/59967 and WO 98/22438).
If the starting materials used are compounds of the formula (II-b), novel insecticidally active Δ1-pyrrolines of the formula (I-b)
in which
If the starting materials used are compounds of the formula (II-c), novel insectidally active Δ1-pyrrolines of the formula (I-c)
in which
If the starting materials used are compounds of the formula (II-d), novel insecticidally active Δ1-pyrrolines of the formula (I-d)
in which
If the starting materials used are compounds of the formula (II-e), novel insecticidally active Δ1-pyrrolines of the formula (I-e)
in which
If the starting materials used are compounds of the formula (II-f), novel insecticidally active Δ1-pyrrolines of the formula (I-f)
in which
Preferably obtained are compounds of the formula (I-f) in which
Particularly preferably obtained are compounds of the formula (I-f) in which
If the starting materials used are compounds of the formula (II-g), novel insecticidally active Δ1-pyrrolines of the formula (I-g)
in which
Preferably obtained are compounds of the formula (I-g) in which
Particularly preferably obtained are compounds of the formula (I-g) in which
Novel Δ1-pyrrolines of the formulae mula (I-b), mula (I-c), mula (I-d), (I-e), (I-f) and (I-g) which can be obtained, for example, by the process according to the invention are also claimed according to the invention.
The practice of the process according to the invention is illustrated by the examples below.
2.1 g (4 mmol) of tert-butyl 3-(2-bromobenzoyl)-2-oxo-5-[4-(trifluoromethoxy)phenyl]-1-pyrrolidinecarboxylate (II-1) are boiled at reflux in 15 ml of glacial acetic acid and 5 ml of concentrated sulfuric acid and 5 ml of water for 3.5 h. After cooling, the reaction mixture is made alkaline using dilute sodium hydroxide solution, the product is extracted with dichloromethane and the organic phase is concentrated under reduced pressure. The residue is chromatographed on silica gel (mobile phase: dichloromethane).
This gives 0.95 g (61.8% of theory) of 5-(2-bromophenyl)-2-[4-(trifluoro-methoxy)phenyl]-3,4-dihydro-2H-pyrrole as an oil.
HPLC: log P (pH 2.3)=3.61.
Analogously to example 1, it is possible to obtain the compounds listed in the table below.
At −50° C., 12 ml (11.6 mmol) of a 1 molar solution of lithium bis(trimethylsilyl)amide in tetrahydrofuran are added dropwise to a solution of 2.0 g (5.8 mmol) of tert-butyl 2-oxo-5-[4-(trifluoromethoxy)phenyl]-1-pyrrolidinecarboxylate (III-1) in 30 ml of tetrahydrofuran and 1.15 g (6.5 mmol) of hexamethylphosphoric triamide. After 10 min of stirring at −50° C., 1.4 g (6.4 mmol) of 2-bromobenzoyl chloride (dissolved in 5 ml of tetrahydrofuran) are then added, and the reaction mixture is allowed to warm to room temperature over a period of 16 h. The mixture is poured into water, acidifed with dilute hydrochloric acid and extracted with dichloromethane. The organic phase is separated off and concentrated under reduced pressure. The residue is triturated with pentane/ethyl acetate and filtered off with suction.
This gives 2.3 g (75.1% of theory) of 3-(2-bromobenzoyl)-2-oxo-5-[4-(trifluoro-methoxy)phenyl]-1-pyrrolidinecarboxylate.
m.p.: 113° C.
HPLC: log P (pH 7.5)=3.35.
In general, compounds of the formula (II) are directly reacted further, without purification.
Analogously to example (II-1), it is possible to obtain the compounds listed in the table below.
13.6 g (55 mmol) of 5-[4-(trifluoromethoxy)phenyl]-2-pyrrolidinone (V-1) in 60 ml of dimethylformamide are, with addition of 0.4 g of dimethylaminopyridine, stirred with 27.6 g (0.13 mol) of di-tert-butyl dicarbonate at 20° C. for 16 h. Most of the solvent is then removed, and the residue is partitioned between water and dichloromethane. The organic phase is again washed with water and concentrated under reduced pressure. The residue is triturated with pentane and filtered off with suction.
This gives 13.7 g (72.1% of theory) of tert-butyl 2-oxo-5-[4-(trifluoromethoxy)phenyl]-1-pyrrolidinecarboxylate.
m.p.: 120° C.
HPLC: log P (pH 2.3)=3.28.
Analogously to example (III-1), it is possible to obtain the compounds listed in the table below. Purification is either as described in the example or by recrystallization or by chromatography.
With 70 ml of liquid ammonia and 2 g of Raney nickel, 19.0 g (72 mmol) of 3-(4-trifluoromethoxybenzoyl)propionic acid in 170 ml of ethanol are, under a hydrogen pressure of 150 bar, heated at 150° C. for 3 h. After cooling, the catalyst is filtered off, the solvent is removed under reduced pressure and the residue is triturated with pentane.
This gives 14.4 g (81.7% of theory) of 5-[4-(trifluoromethoxy)phenyl]-2-pyrrolidinone of melting point 105-106° C.
HPLC: logP (pH 2.3)=2.00.
Hydrogen fluoride (2500 ml) is initially charged at 0° C. A solution of 5-ethoxy-2-pyrrolidinone (264 g, 2.04 mol) and 4-[(trifluoromethyl)thio]-1,1′-biphenyl (260 g, 1.02 mol) in dichloromethane (400 ml) is added dropwise. The reaction mixture is then stirred at room temperature, and the hydrogen fluoride is finally removed under reduced pressure. The residue is taken up in dichloromethane and washed with saturated aqueous sodium bicarbonate solution. The organic phase is dried over magnesium sulfate, filtered and concentrated. The crude products of two batches are combined and initially stirred with toluene. The crude product is then purified by silica gel chromatography (mobile phase: ethyl acetate/ethanol 7:3 v/v).
This gives off 5-{4′-[(trifluoromethyl)thio]-1,1′-biphenyl-4-yl}-2-pyrrolidinone “para” isomer: 173.2 g (25% of theory)
5-Ethoxy-2-pyrrolidinone (11.5 g, 0.1 mol) is initially charged at 0° C. in a mixture of glacial acetic acid (89 ml) and concentrated sulfuric acid (10 ml). 1-Tert-butyl-3-ethoxybenzene (19.61 g, 0.11 mol) is added, and the reaction mixture is then stirred at 0° C. for 2 h and at room temperature for 48 h. The reaction mixture is poured onto ice and repeatedly extracted with ethyl acetate. The combined organic phases are washed with aqueous saturated sodium bicarbonate solution, dried over magnesium sulfate, filtered and concentrated.
This gives 23.62 g (75% of theory) of 5-(4-tert-butyl-2-ethoxyphenyl)-2-pyrrolidinone.
HPLC: log P (pH 2.3)=2.84 (83% purity)
Analogously to one of examples (V-1) to (V-3), it is possible to obtain the compounds listed in the table below. Purification is either as described in the example or by recrystallization or by chromatography.
The logP values given in the tables and preparation examples above are determined in accordance with EEC directive 79/831 Annex V.A8 by HPLC (High Performance Liquid Chromatography) on a reverse-phase column (C 18). Temperature: 43° C.
In the acidic range, the determination is carried out at pH 2.3 using the mobile phases 0.1% aqueous phosphoric acid and acetonitrile; linear gradient from 10% acetonitrile to 90% acetonitrile. (In the tables, the measurement values obtained are marked a).)
In the neutral range, the determination is carried out at pH 7.5 using the mobile phases 0.01 molar aqueous phosphate buffer solution and acetonitrile; linear gradient from 10% acetonitrile to 90% acetonitrile. (In the tables, the measurement values obtained are marked b).)
Calibration is carried out using unbranched alkan-2-ones (having 3 to 16 carbon atoms) with known logP values (determination of the logP values by the retention times using linear interpolation between two successive alkanones).
The lambda max values were determined in the maxima of the chromatographic signals using the UV spectra from 200 nm to 400 nm.
Number | Date | Country | Kind |
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101 17 675 | Apr 2001 | DE | national |
101 33 929 | Jul 2001 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP02/03855 | 4/8/2002 | WO | 00 | 3/8/2004 |
Publishing Document | Publishing Date | Country | Kind |
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WO02/081442 | 10/17/2002 | WO | A |
Number | Name | Date | Kind |
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6274613 | Plant et al. | Aug 2001 | B1 |
6399771 | Plant et al. | Jun 2002 | B1 |
6489490 | Plant et al. | Dec 2002 | B1 |
6599924 | Plant et al. | Jul 2003 | B1 |
6632833 | Plant et al. | Oct 2003 | B1 |
20020151571 | Plant et al. | Oct 2002 | A1 |
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2332522 | Nov 1999 | CA |
WO 9822438 | May 1998 | WO |
9959968 | Nov 1999 | WO |
WO 9959967 | Nov 1999 | WO |
0050380 | Aug 2000 | WO |
Number | Date | Country | |
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20040147764 A1 | Jul 2004 | US |