JPH0813758B2 - Method for producing trifluoromethyl-substituted ethylene derivative - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel method for producing a trifluoromethyl-substituted ethylene derivative, and more particularly to an aldehyde and 1,1,1-trichloro-2,2,2- The present invention relates to a method for producing a trifluoromethyl-substituted ethylene derivative by reacting with trifluoroethane.

Conventional techniques and problems So far, as a method for producing a trifluoromethyl-substituted ethylene derivative by reacting an aldehyde with 1,1,1-trichloro-2,2,2-trifluoroethane, for example, zinc is stoichiometrically Method of using more than amount [Tetrahedron Lett., 27 , 3
655 (1986)] is known. However, in this method, the yield is not always high, and since a heavy metal is required in a stoichiometric amount or more, a serious problem in terms of pollution is included.
There are problems in carrying out on an industrial scale, and the yield is not always satisfactory.

OBJECT OF THE INVENTION The object of the present invention is a method for producing a trifluoromethyl-substituted ethylene derivative represented by the above-mentioned general formula (II) which is industrially advantageous in a high yield by a safe and simple operation without the above-mentioned problems. To provide.

SUMMARY OF THE INVENTION [Wherein R represents hydrogen or a chain or cyclic alkyl, alkenyl, alkynyl group, aralkyl group, aryl group or heterocyclic group, which may be the same or different, and may be a carbon chain or a carbon atom containing a hetero atom. The chain may form a ring. Further, these may have a substituent. ] The aldehyde represented by the formula 1,1,1-trichloro-2,2,2 in the presence of a lead compound, a metal having a greater ionization tendency than lead and an acid anhydride or an acid halide in a polar solvent.
A general formula characterized by reacting with trifluoroethane [Wherein R is as defined above. ] It relates to a method for producing a trifluoromethyl-substituted ethylene derivative represented by

The trifluoromethyl-substituted ethylene derivative represented by the general formula (II) obtained in the present invention is an important compound as an intermediate for synthesizing drugs, agricultural chemicals and the like. For example, it is derived from a chrysanthemic acid derivative having a trifluoromethyl group, which is a raw material of a synthetic pyrethroid insecticide having excellent weather resistance and insecticidal activity.

In the present invention, R is hydrogen or a chain or cyclic alkyl, alkenyl, alkynyl group or aralkyl group,
It represents an aryl group or a heterocyclic group, which may be the same or different and may form a ring with a carbon chain or a carbon chain containing a hetero atom. Furthermore, these may have a substituent.

Preferred chain alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t
-Butyl, amyl, isoamyl, hexyl, octyl,
Examples thereof include C _{1 to} C ₂₀ linear or branched alkyl groups such as decyl and dodecyl.

Cyclopropyl is a preferable cyclic alkyl group,
Cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, alicyclic group, and a 1-methylcyclopropyl of C ₃ -C _16, such as a cyclodecyl, 2,2-dimethyl-cyclopropyl, 3-methyl-cyclobutyl, 1-methylcyclopentyl, 3- Ethylcyclopentyl, 3-t-butylcyclopentyl, 4-isopropylcyclohexyl, 4-t
And a C ₃ -C ₁₆ alicyclic group having at least one C ₁ -C ₂₀ side chain of a -butylcyclohexyl group.

Preferred chain alkenyl and alkynyl groups are vinyl, ethynyl, 1-propenyl, 2-methyl-1-propenyl, propynyl, 3-butenyl, butynyl, pentenyl, pentadienyl, pentynyl, hexenyl, hexynyl, heptenyl, heptynyl, octenyl, C ₂ -C such as octynyl, 9-decenyl, prenyl, geranyl
There may be mentioned ₂₀ straight-chain or branched unsaturated hydrocarbon radicals.

Preferred cyclic alkenyl groups include cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclooctadienyl and the like.
It can be mentioned alicyclic unsaturated hydrocarbon radical of C ₃ -C _16.

Specific examples of preferable aralkyl groups include benzyl, phenethyl, phenylbutyl, diphenylmethyl, triphenylmethyl, naphthylmethyl, naphthylethyl and the like.

The preferred aryl group is a phenyl group or a polynuclear aromatic hydrocarbon group, and specific examples of the polynuclear aromatic hydrocarbon group include α-naphthyl, β-naphthyl, anthranyl and pyrenyl groups.

Preferred heterocyclic groups include cyclic groups containing oxygen, nitrogen, sulfur atoms and the like, and specific examples thereof include tetrahydrofuryl, furyl, tetrahydropyranyl, pyranyl, pyrrolyl, piperidinyl, pyridyl, oxazolyl, morpholinyl, tetrahydro. Examples thereof include thienyl, thienyl, thiadiazolyl, triazolyl, thiazolyl, triazolyl and tetrazolyl groups.

In the case of forming a ring with carbon chain containing a carbon chain or heteroatom [- (CH ₂₎ k _-], a (k is 2 to 13) -CH ₂
-In place of the group, a hetero atom such as oxygen, nitrogen, or sulfur may enter.

As the substituents of the above R, a hydroxyl group, a protected hydroxyl group, an acyloxy group, a halogen, a C _{1 to} C ₅ straight chain or branched alkyl group, and a C _{2 to} C ₆ straight chain or branched unsaturated hydrocarbon group. Groups, aralkyl groups, amino groups, amino groups substituted with C _{1 to} C ₅ linear or branched alkyl groups, protected amino groups, nitro groups, protected thiol groups, carboxyl groups, protected carboxyl groups A group, a sulfonic acid group, a protected sulfonic acid group, and a cyano group, the number of the substituents is 1 to 5, and these may be the same or different. Examples of the hydroxyl-protecting group include lower alkyl groups such as methyl, ethyl, propyl, isopropyl and butyl groups, or greene (Theodora W. Greene)
Author of "Protective Groups in Organic Synthesis" (AW
The protective group for the hydroxyl group described in Chapter 2 of eiley-Interscience Publication, 1981) can be mentioned. Specific examples of the acyloxy group include formyloxy, acetyloxy, propionyloxy, valeryloxy, benzoyloxy, toluoyloxy and furoyloxy groups. As halogen, fluorine, chlorine, bromine,
Iodine can be mentioned. Examples of the C _{1 to} C ₅ linear or branched alkyl group include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, amyl and isoamyl groups. Examples of the C _{2 to} C ₆ linear or branched unsaturated hydrocarbon group include vinyl, ethynyl, propenyl, butenyl, and hexenyl groups, and examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, phenylbutyl, and diphenylmethyl groups. Etc. can be mentioned.
Examples of the C _{1 to} C ₅ linear or branched alkyl group substituted with an amino group include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, amyl, isoamyl groups and the like. Examples of the amino-protecting group include the amino-protecting groups described in Chapter 7 of the same book. Examples of the protective group for the thiol group include C _{1 to} C ₅ alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, amyl and isoamyl groups, phenyl, benzyl and phenethyl groups. Examples of the carboxyl-protecting group include the carboxyl-protecting groups described in Chapter 5 of the same book. Examples of the protective group for the sulfonic acid group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, amyl and isoamyl groups, and aralkyl groups such as phenyl, benzyl and phenethyl groups.

Further, specific examples of the above-mentioned substituents substituted with these groups include general formulas [In the formula, R 'is hydrogen or the above-mentioned carboxylic acid-protecting group].

In the present invention, 1,1,1-trichloro-2,2,2-trifluoroethane may be used in an equivalent amount with respect to the aldehyde represented by the general formula (I), but it is preferable to use it in a slight excess. Is obtained, and the preferred range of use is 1 to 4 equivalents relative to 1 equivalent of the aldehyde represented by the general formula (I).

Next, the solvent used in the present invention is preferably a polar solvent, for example, alcohols, ethers, nitriles, amides and the like, specifically, methanol, tetrahydrofuran, dioxane, acetonitrile, dimethylformamide, N-methyl-2-pyrrolidone. , 1,3-dimethyl-2
-Imidazolidinone, dimethyl sulfoxide and the like, which may be used alone or as a mixture. Water may be contained as needed. Particularly preferred is dimethylformamide, and its use amount is not particularly limited, but is preferably at least an amount in which the raw material is completely dissolved. However, even if it is less than that, there is no problem because the reaction proceeds, but it may be difficult to carry out the operation, or there may be problems such as a decrease in yield.

The lead compound used in the present invention may have a lead valence of 0, 2, or 4, and these compounds may be in the form of a hydrate. As the lead compound used, conventionally known compounds can be widely used. For example, lead halides such as lead fluoride, lead chloride, lead bromide, lead iodide, etc., lead nitrate, lead sulfate, lead perchlorate, lead borate, lead carbonate, lead acid phosphates, etc., lead acetate. Examples thereof include fatty acid lead such as lead oxalate and lead stearate. These lead compounds can be used alone or in combination of two or more. Particularly preferred are lead halides such as lead fluoride, lead chloride, lead bromide and lead iodide. The amount of these lead compounds used is preferably 0.001 to 0.5 equivalents per 1 equivalent of the aldehyde of the general formula (I) usually used as a starting material,
If it is less than 1 equivalent, the effect is small, and if it is more than 0.5 equivalent, the effect remains the same but it is not economical.

The metal having a greater ionization tendency than lead used in the present invention includes any one of aluminum, iron, nickel, tin, cobalt and magnesium, or a mixture thereof, with aluminum being particularly preferred.
The shape of these metals used is not particularly limited, and various shapes such as powder, plate, foil, lump or needle can be used. The amount used is preferably in the range of 0.7 to 6 equivalents relative to 1 equivalent of the aldehyde of the general formula (I). If the amount is less than 0.7 equivalents, the reaction will proceed slowly or the reaction will stop, resulting in 6 equivalents or more. Is not economical, and side reactions occur to lower the yield.

Further, as the acid anhydride or acid halide used in the present invention, for example, an acid anhydride of C _{1 to} C ₁₂ monocarboxylic acid or an acid halide thereof can be used, but particularly preferred are acetic anhydride, propionic anhydride, Examples of the acid include lactic acid anhydride, and the amount thereof is the aldehyde 1 of the general formula (I).
It is preferably in the range of 1 to 4 equivalents with respect to the equivalent.

In the present method, the presence of the above solvent and catalyst system is essential, and even if any of them is lacking, the object of the present invention cannot be achieved.

The reaction temperature in the present invention is preferably in the range of about 0 to 100 ° C, preferably 0 to 40 ° C, although the preferable range varies depending on the starting materials, the amount of the acid anhydride or acid halide used, the solvent and the like.
Will be held in.

[Examples] The present invention will be described more specifically below with reference to Examples.

Example 1 In a round bottom flask, 18 mg (0.05 mmol) of lead bromide and 270 mg (10 mmol) of finely cut aluminum foil were placed, and 10 ml of dimethylformamide, benzaldehyde (1) 53
0 mg (5 mmol), CF ₃ CCl ₃ (2) 1.41 g (7.5 mmol) and acetic anhydride 1.02 g (10 mmol) were added, and 0 to 5
The reaction was carried out by stirring at 0 ° C for 2 hours. After completion of the reaction, 10 ml of water was added to the reaction solution and extracted with ethyl acetate. The extract was washed with saturated aqueous sodium hydrogen carbonate and saturated brine, dried over anhydrous magnesium sulfate, and concentrated to give a yellow oil (1.0 g). This product was purified using a silica gel column to obtain 930 mg (yield 90%) of colorless liquid compound (3). The by-product of the compound (4) was 1% or less.

Compound (3): ¹ H-NMR (CDCl ₃ ) δ 7.15 to 7.85 (m, 6H,
-CH = C, Ph). Examples 2-8 The reaction was performed under the same conditions as in the method of Example 1 except that shown in Table 1, and the products shown in Table 1 were obtained in high yield and high selectivity.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C07C 43/225 B 7419-4H 69/743 // C07B 61/00 300

Claims (2)

[Claims] 1. A general formula [Wherein R represents hydrogen or a chain or cyclic alkyl, alkenyl, alkynyl group, aralkyl group, aryl group or heterocyclic group, which may be the same or different, and may be a carbon chain or a carbon atom containing a hetero atom. The chain may form a ring. Further, these may have a substituent. ] The aldehyde represented by the formula 1,1,1-trichloro-2,2,2 in the presence of a lead compound, a metal having a greater ionization tendency than lead and an acid anhydride or an acid halide in a polar solvent.
A general formula characterized by reacting with trifluoroethane [Wherein R is as defined above. ] The manufacturing method of the trifluoromethyl substituted ethylene derivative represented by these. 2. The method according to claim 1, wherein the metal having a higher ionization tendency than lead is any one of aluminum, iron, nickel, tin, cobalt, magnesium, or a mixture thereof.