JPS58177924A - Preparation of cis-alkenyl chloride - Google Patents

Abstract

PURPOSE:To prepare the titled substance which is a synthetic intermediate for sex pheromone useful for the control of vermin, in high yield, by reacting alpha- bromo-omega-chloroalkane with a Grignard reagent derived from easily available cis- 3-alkenyl chloride. CONSTITUTION:The objective compound of formula III is prepared by reacting (A) a Grignard reagent derived from cis-3-alkenyl chloride of formula I (R is 1- 8C alkyl) with (B) alpha-bromo-omega-chloroalkane of formula II in the presence of (C) preferably lithium copper dichloride, etc. as a catalyst. The amount of the compound of formula II is preferably 0.9-1.1mol per 1mol of the compound of formula I . The grignard reagent of the compound of formula I can be prepared by reacting the compound of formula I with metallic magnesium in anhydrous tetrahydrofuran at 40-66 deg.C in a conventional manner.

Description

Detailed Description of the Invention The present invention is based on the general formula % (%) (in the formula, R represents an alkyl group having 1 to 8 carbon atoms, and n
is an integer from 4 to 8).

In recent years, pesticides such as insecticides have become a social problem due to their toxic effects on those who handle them.

In order to deal with this problem, biological pest control methods are being researched, and one of these methods is to chemically synthesize sex pheromones released by female pests, and use this to control promiscuous pests by disrupting communication. Proposed. This method of control is particularly effective against insect pests, and is attracting attention and consideration in countries around the world, but such sex pheromone substances have already been registered as pesticides in the United States and have reached the stage of practical application. There are some things.

The sexual ferrocontaining substance of the linolemoku moth is different for each insect pest, but it is a linear hydrocarbon with an acetyloxy group, formyl group, or hydroxyl group at the end, and has one or two double bonds in the molecule. Most of them are structural.

Conventionally, methods for synthesizing the above-mentioned sex pheromone substances include (a) a method using the Witt 1g reaction published in Tetrahedron Vol. 33, page 1845 (1977, 1); There is a method of coupling acetylide and alkyl iodide to increase the number of carbon atoms, but in the case of method (a), the purity of the pheromone substance produced by the reaction is poor;
Its purification is difficult, and in the case of method (b), it is necessary to use liquid ammonia as a solvent, and a pressure-resistant device is required for low-temperature reaction (-40°C to -20°C). Both methods are economically and industrially disadvantageous.

Therefore, cis-alkenyl chloride is considered to be a very useful intermediate for synthesizing sex pheromone substances that are applied as pheromone pesticides to pest control. That is, from this intermediate, various sex pheromone substances can be systematically synthesized as shown in the reaction formula below.

(1) Acetylation reaction Potassium acetate 8°u=cHcH・0′″−(°S・0″,,aRC
)T=CHOH,C! H, (C)(,)nOCCH.

1 (Summer) The pest groups corresponding to the specific types of R and n in the above product (1) are listed below.

(1) Rn pest name 26 Wp
stern Pin+! 1Photo bOrprGr
app berry rr+r+th2 8 Chaba maki, Chanokokakumon hemaki, Apple kokakumon hemaki 3 5 Suν Hime νnkui 4 6 Chanokokakumon hemaki, Apple kokakumon hemaki (2) Hydrolysis reaction RCH=CHCH, CH, (CM,) nOOCH.

(1 (1) (3) Oxidation reaction RCH=C) (CH, CM, (CM,) nOH (1) (*) Rn In this way, the pest basic invention is an extremely important intermediate for the synthesis of sex pheromone substances. provides an advantageous synthesis of cis-alkenyl chlorides of the general formula
H=C*O)? ,C! A Grignard reagent of cis-3-alkenyl chloride represented by H, C1 (R in the formula is an alkyl group having a carbon shoji number of 1 to 8) and a Grignard reagent of the general formula B r (C
General formula RCT(-0)(C)(,OH
,(C)! , )nC] (R and n are as above)
This invention relates to a method for producing a less-alkenyl chloride shown in the following.

To explain this, the method of the present invention is characterized by the use of easily available su-3-alkenyl chloride as the main raw material. Examples of the cis-3-alkenyl chloride include cis-3-hexenyl chloride and cis-3-hebutenyl chloride.

Examples include cis-3-octenyl chloride,
These are synthesized as follows. That is, a tetrahydrofuran solution of methylmagnesium clot is prepared in a conventional manner, an alkyl acetylene is added dropwise to the solution while stirring, and the resulting alkyl acetylene magnesium chloride is reacted with ethylene oxide, followed by a hydrolysis reaction to obtain 3- Alkyne-1-ol is produced. By hydrogenating this product using a Lindlar catalyst and then chlorinating it with a chlorinating agent such as thionyl chloride, cis-3-alkenyl chloride can be obtained in high yield. This is shown as a reaction formula.

RC"F:OH+ CH3MgC]-→RC=CM〆C] As the other reaction material, α-bromo-ω-chloroalkane, l-bromo-4-chloro-butane, l-
Examples include bromo-5-ri[sigma]lopentane, l-proso-6-chlorohexitine, and 1-bromo-4-10rooctane. These are mixed with concentrated hydrochloric acid in the presence of the corresponding α,ω-alkanediol heptane or toluene solvent, stirred under reflux, and then branched vacuum distillation of the organic layer is performed to obtain l-chloro-ω-alkanol. It will be done. Next, this l-chloro-ω-alkanol and red phosphorus are mixed, and bromine is added dropwise to the reaction system at a reaction humidity of 20"C or less, followed by stirring at 60°C and the reaction solution is distilled under reduced pressure to obtain a high yield. α-Furomoω-chloroalkane can be obtained at a certain rate.In particular, in the case of ]-bromo-4-chloro-butane, tetraheptadurofuran and zinc chloride are mixed, and hydrochloric acid gas is blown into the mixture under reflux and stirring. After that, red phosphorus is added, bromine is added dropwise, and the reaction solution is distilled under reduced pressure to easily obtain it.

The Grignard reagent of cis-3-alkenyl chloride is obtained as a tetrahydrofuran solution of cis-3-alkenylmagnesium chloride by reacting cis-3-alkenyl chloride with metallic magnesium at 40 to 66° C. in an ordinary method in anhydrous tetrahydrofuran.

By reacting the Grignard reagent of cis-3-alkenyl chloride prepared in this manner with α-bromo-ω-chloroalkane, V-salkenyl chloride is produced.
The desired cis-alkenyl chloride can be obtained in high yield by dropping the Grignard reagent into a tetrahydrofuran solution of ω-chloroalkane at an anti-gS temperature of 0 to 40°C (see reaction below).

ROT(=CHCH, CJT, MgC1+ Br (
CM,)nC1-→RCH=CI(OH,C)I, (
CM,)nC1+gBrC1 In the above reaction, the reaction molar ratio is preferably 0.9 to 1.1 mol of α-bromo-ω-chloroalkane per 1 mol of Grignard reagent of cis-3-alkenyl chloride; It is desirable to use LiCuC1° (9 thiium dichloride) or Li, CuCl2 (lithium tetrachloride fA) as a catalyst to promote the cross-coupling reaction.

The above lithium dichloride can be prepared by adding lithium chloride and cuprous chloride in a ratio of 1:1 (molar ratio) to tetrahydrochloride and mixing. 0.001 to 0 per mol of reagent, preferably 0.003 per mol
It is preferable to use 0.02 mol.

The reaction solution obtained by the cross-coupling reaction as described above is hydrolyzed with a hydrochloric acid-ammonium chloride aqueous solution, the organic phase is taken out, concentrated, and distilled to obtain the target less alkenyl chloride. obtained in high yield.

This cross-coupling reaction occurs between a Grignard reagent and an alkane compound having a carbon-bromine bond or a carbon-iodine bond.

It does not occur between Grignard reagents and alkane compounds with carbon-chlorine bonds.

In the method of the present invention, α-bromo-ω-
Due to the selective use of chloroalkanes, α.

Compared to the coupling reaction of ka-υ bromoalkane and Grignard reagent (see the reaction formula below), the reaction selectivity and yield are better.

3 ROH=OHCH, OH, Mgρ1 + 2
Br (fUF(m) nRrRCH=CHCH,OH
, (ClH,)nBr +ROH=CHOH,0)-1
, (O)T, )nO)(,OH,Cl-1=o)I
R (by-product) Next, specific examples will be given.

Example 1 A reactor having an internal volume of 1 mm was charged with 24P (1 mole) of magnesium metal, 360P of anhydrous tetrahydrofuran, and 1 piece of iodine, and cis-3 was added to the mixture at an internal temperature of 40°C.
118.57' (1 mol) of -hexyl-1-chloride was added dropwise over 2 hours. After the addition was completed, the mixture was stirred at 60° C. for another hour to complete the reaction, and then cooled to 20° C., and the reaction solution (Grinard reagent) was charged into a dropping funnel.

l-Bromo-6-chloro-
Hexane 1995 mm (1 mol) and L 1 * Cu C
], a in tetrahydrofuran solution (LiC143
0 Misaki and CuCl*676"l dissolved in tetrahydrofuran 2001) were charged, and the Grignard reagent was added dropwise thereto at an internal temperature of 10 to 15°C. After the addition was completed, the mixture was stirred at 40°C for 1 hour. The reaction was completed.

The reaction solution was poured into a hydrochloric acid-ammonium chloride aqueous solution for hydrolysis, and the organic phase was branched and concentrated and distilled under reduced pressure.
1P (yield 85%) was obtained.

The thus obtained cis-9-dodecene-1-chloride 172j', glacial acetic acid 255P and potassium acetate 298i! - was charged into a reactor having an internal volume of IJ, and the mixture was reacted at reflux temperature (164°C) for 9 hours with stirring. After the reaction was completed, the mixture was cooled to below 100°C, 300°C of water was added, and the organic phase was branched and distilled under reduced pressure to obtain 170°C of cis-9-dobutynylacetate (90% yield). .

This is the sex pheromone of the grape berry moth.

Examples 2 to 4 Cis-3-alkenyl chloride and α-bromo-ω-chloroalkane as shown in Table 1 were reacted according to the previous example to give cis-3-alkenyl chloride with the respective yields shown in Table 1. Alkenyl chloride and cis-alkenyl acetate were obtained.

Claims (1)

[Scope of Claims] 1. General formula HCH (HCH, OR, R in the Clc formula)
is an alkyl group having 1 to 8 carbon atoms)
- Grignard reagent of alkenyl chloride and the general formula Br (O)T, )nClc (where n is an integer from 4 to 8)
A method for producing a cis-alkenyl chloride represented by the general formula % (where R and n are as described above), characterized by reacting an α-bromo-ω-chloroalkane represented by the formula %)! , the reaction is carried out by LiCuC1, and/or L1□C
'u The method according to claim 1, characterized in that it is carried out in tetrahydrofuran in the presence of C1a.