JP3363509B2 - Method for producing 5-tetradecenoic acid ester - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a 5-tetradecenoic acid ester which is a sex pheromone such as Coleoptera insects Anomala rufocuprea.

[0002]

2. Description of the Related Art Coleopteran insects such as the soybean beetle are also called soybean beetles.
It was known as an important pest for field crops. In 1985 Tamaki et al. Identified and reported the sex pheromone as methyl cis-5-tetradecenoate (formula I) [Appl. En
t. Zool. 20 (3) 359 (1985)]. _{CH 3 (CH 2) 7 CH} = CH (CH 2) 3 COOCH 3 ··· (I)

At present, a technique of utilizing this sex pheromone for predicting the occurrence has been put into practical use. As a method of producing this sex pheromone, in the above-mentioned Tamaki et al.
A method for oxidatively cleaving bromine from bromopentanoic acid and Wittig condensation is described. In addition, JP-A-4
No. 178350 describes a method in which 1-decyne is converted to a metal acetylide, which is reacted with 4-bromobutyric acid, which is then methyl esterified, and then the triple bond is reduced.

[0004]

However, the former method has the drawback that the materials are expensive and the yield is low. Also, in the latter case, 4-bromobutyric acid is not always inexpensive, and there is a drawback in that materials such as hexamethylphosphoric triamide used for alkylation and diazomethane used for esterification that require careful handling are used. there were.

Therefore, an object of the present invention is to provide a method for producing 5-tetradecenoic acid ester which can inexpensively supply a sex pheromone in a practically usable amount.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventor has found that by using a material which is easy to handle and inexpensive, and a reaction step with a high yield,
A method for producing a tetradecenoic acid ester has been conceived.

In order to achieve the above object, the method for producing 5-tetradecenoic acid ester according to claim 1 has the general formula CH ₃ (C
H ₂ ) ₇ CH═CH (CH ₂ ) ₃ M (wherein M represents an alkali metal or a MgX group, and X of the MgX group represents a halogen atom), and YCOOR
(Wherein Y is a halogen atom and R is an alkyl group) is reacted with a haloformate ester.

To achieve the above object, the invention of claim 2 is
In the method for producing 5-tetradecenoic acid ester according to claim 1, the 5-tetradecenoic acid ester is cis-5-tetradecenoic acid ester.

In the production method according to the present invention, the reaction proceeds according to the following formula (II).

[Chemical 1] That is, the present invention provides the general formula CH ₃ (CH ₂ ) ₇ CH
= CH (CH ₂ ) ₃ M (where M is an alkali metal or M
A cross-coupling between an organometallic compound represented by a gX group, where X of the MgX group represents a halogen atom) and YCOOR (wherein Y is a halogen atom and R is an alkyl group).

Organometallic compound CH as the starting material of the present invention₃
(CH₂)₇CH = CH (CH₂) ₃M is, for example,
Knowledge 1-halo-4-tridecene:       CH₃(CH₂)₇CH = CH (CH₂)₃Z ... (III) Can be easily derived from (where Z is a halogen element)
Bare). Specifically, it is present in ether with nitrogen gas.
Below, if you react with thinly sliced lithium pieces, organic lithium
Mu compound:       CH₃(CH₂)₇CH = CH (CH₂)₃Li ... (IV) Is obtained. In addition, anhydrous tetrahydrofuran or
If reacted with metallic magnesium in water ether,
Linhar compound:         CH₃(CH₂)₇CH = CH (CH₂)₃MgX ... (V) Is obtained.

On the other hand, the haloformic acid ester [YC
Representative examples of OOR (wherein Y is a halogen atom and R is an alkyl group) include methyl chloroformate or ethyl chloroformate, and in the case of the sex pheromone of the Japanese beetle, methyl chloroformate may be reacted.

The reaction is carried out by dropping an organometallic compound into a haloformic acid ester dissolved in various solvents.

The reaction temperature is -78 ° C to 60 ° C, preferably -30 ° C to 15 ° C.

The solvent used is preferably tetrahydrofuran, diethyl ether or the like. The amount to add is C
_{H 3 (CH 2) 7 CH} = CH (CH 2) 1 mole per 300~1500g of ₃ M. Hexamethylphosphoric triamide (HMPA) and dimethylimidazoline (DM
A hydrophilic solvent such as I) may be used in combination, but in this case, DMI having low toxicity is preferable.

The molar ratio of the reaction product is preferably such that the haloformic acid ester is in a slight excess with respect to the organometallic compound, and usually 1.1 to 1.3 times mol of the haloformic acid ester is used with respect to the organometallic compound. .

After completion of the reaction, saturated aqueous ammonium chloride solution and hydrochloric acid are added to separate the layers. The organic layer thus obtained can be concentrated and the 5-tetradecenoic acid ester can be obtained by a usual separation operation such as distillation or column chromatography.

[0017]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples.

Example 1 60 ml of dry anhydrous ether was placed in a synthetic flask by the lithium method of methyl cis-5-tetradecenoate (sex pheromone of the Japanese beetle), and 1.4 g of metal lithium pieces (thin slices) were placed under a nitrogen atmosphere.
And cool to 0 ° C. in an ice bath. Then, 24.8 g (0.095 mol) of 1-bromo-cis-4-tridecene
Is dissolved in 50 ml of anhydrous ether and slowly added dropwise. When the mixture was stirred at 0 ° C. for 1 hour after the dropping, lithium pieces were consumed and a large amount of white precipitate was generated. After leaving it for 1 hour, the supernatant was extracted into a dropping funnel.

Next, while dissolving 10.4 g (0.11 mol) of methyl chloroformate in 80 ml of anhydrous ether, the above organometallic solution was added dropwise at -20 ° C over 1 hour.
After the completion of dropping, the mixture was stirred as it was until it reached room temperature. Then, 60 ml of a saturated aqueous solution of ammonium chloride was added dropwise at 0 ° C., and then 21 ml of 10% hydrochloric acid was added. The organic layer was taken out, washed with a 5% sodium hydrogen carbonate solution, and ether was removed under reduced pressure. When the residue was distilled under reduced pressure, cis-5
-13.9 g of methyl tetradecenoate (purity 93%, yield 61%) were obtained. IR, ¹ H-NMR, ¹³ C-N
It was confirmed by MR, GC-MS (gas chromatography / mass spectrometry) that this compound was methyl cis-5-tetradecenoate. FIG. 1 is an IR spectrum diagram of the obtained compound, FIG. 2 is a GC-MS diagram, and Table 1
The chemical shifts confirmed by ¹ H-NMR and ¹³ C-NMR of the obtained compound are shown below.

[0020]

[Table 1]

Example 2 Synthesis of methyl cis-5-tetradecenoate (sex pheromone of the Japanese beetle) by the Grignard method Under a nitrogen atmosphere, anhydrous tetrahydrofuran 30 was added to a flask.
ml and 2.5 g (0.103 mol) of magnesium metal, 0.1 g of iodine pieces were added, and 1-chloro-cis-4 was added.
A solution of 21.6 g (0.1 mol) of tridecene dissolved in 40 ml of anhydrous tetrahydrofuran was added dropwise from 40 ° C,
It was made to react. After completion of dropping, the mixture was stirred at 67 ° C. for 3 hours to prepare a Grignard reagent.

Next, in another flask, 80 ml of anhydrous tetrahydrofuran and 10.4 g (0.11 g) of methyl chloroformate were added.
The above-mentioned Grignard reagent was added dropwise from −30 ° C. into the solution. After completion of the dropping, with vigorous stirring,
The stirring was continued gradually until room temperature. Then, the mixture was cooled to 0 ° C., 60 ml of a saturated aqueous ammonium chloride solution was added dropwise, and 19 ml of 10% hydrochloric acid was added. Take out the organic layer,
It was washed with a 5% sodium hydrogen carbonate solution, and tetrahydrofuran was removed under reduced pressure. When the residue was distilled under reduced pressure, 13.9 g of methyl cis-5-tetradecenoate (purity 95%,
Yield 70% was obtained (bp.145-148 ° C / 2)
mmHg). IR, ¹ H-NMR, ¹³ C-NMR, GC
-MS confirmed that the compound was methyl cis-5-tetradecenoate.

[0023]

As is apparent from the above, according to the present invention, 5-tetradecenoic acid ester can be produced by a high yield reaction step using a material which is easy to handle and inexpensive. It is possible to inexpensively supply a sex pheromone in a practically usable amount.

[Brief description of drawings]

FIG. 1 is an IR spectrum diagram of a compound obtained according to the present invention.

FIG. 2 is a graph showing GC-of the compound obtained according to the present invention.
FIG.

Continuation of front page (56) Reference JP-A-6-239705 (JP, A) JP-A-6-116204 (JP, A) JP-A-4-178350 (JP, A) JP-A-4-74154 (JP , A) JP-A-2-243606 (JP, A) JP-A-63-198637 (JP, A) JP-A-61-134348 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB) Name) C07C 69/533 C07C 67/343 C07C 67/36

Claims (2)

(57) [Claims] 1. The general formula CH ₃ (CH ₂ ) ₇ CH═CH
(CH ₂ ) ₃ M (wherein M represents an alkali metal or a MgX group, and X of the MgX group represents a halogen atom) is added to YCOOR (wherein Y is a halogen atom and R is an alkyl group). ) The haloformic acid ester represented by the formula (5) is reacted to produce a 5-tetradecenoic acid ester. 2. The 5-tetradecenoic acid ester is cis-
The method according to claim 1, which is a 5-tetradecenoic acid ester.