JP2000247961A - 3-halo-2-isoxazoline and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound having no substituent and useful as a precursor, a physiologically active skeleton, a herbicide and an insecticide/ acaricide. SOLUTION: This compound is represented by the formula (X is chlorine, bromine or iodine) e.g. 3-chloro-2-isooxazoline. The compound of the formula is obtained by reacting a halonitrile of the formula: X-C≡N→O with ethylene wherein the halonitrile is obtained by reacting glyoxylic oxime with a halogenating agent such as N-chlorosuccinimide, t-butyl hypochlorite or N- bromosuccinimide in an ether solvent (e.g. tetrahydrofuran, dioxane or dimethoxyethane) in the presence of a base (e.g. potassium carbonate) and proper amount of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an unsubstituted 3-halo-2-isoxazoline.

[0002]

2. Description of the Related Art As a method for producing isoxazoline, a method via a corresponding nitrile oxide is generally known. For example, K. Halling: Liebigs A
nn. Chem. According to 1989 985-990, 5
3-Halo-2-isoxazolines having various substituents at positions have been synthesized. In addition, SU 1707016 (C
A 117 90268) includes the preparation of 5-substituted-halo-isoxazoles along with 5-phenyl-3-chloro-
The preparation of 2-isoxazolines has been described. However, the above literature does not describe 3-halo-2-isoxazoline having no substituent.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a 3-halo-2-isoxazoline having no substituent and a method for producing the same.

[0004]

According to the present invention, there are provided (a) a general formula (1)

[0005]

Embedded image

(Wherein X represents a chlorine atom, a bromine atom or an iodine atom), (b) the following formula:

[0007]

Embedded image

(Wherein, X represents the same meaning as described above)
Reacting halonitrile oxide represented by the following formula with ethylene and (c) adding a chlorinating agent, a brominating agent or an iodizing agent to 3-isooxazolidone. A process for producing said 3-halo-2-isoxazoline, characterized by reacting.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The production method of the compound of the present invention will be described below.

Production method 1 Nitrile oxide method

[0011]

Embedded image

(Wherein, X has the same meaning as described above.)

In this nitrile oxide method, dihaloformaldoxime is generally used to generate halonitrile oxide with a base and react with ethylene to obtain a product. The reaction method differs depending on the type of halogen. That is, in the case of chlornitrile oxide, it is desirable to carry out the reaction under pressure, and in the case of bromonitrile oxide, it is necessary to simultaneously add a base while blowing ethylene into the reaction system. In this case, when ethylene is blown in after the addition of the base, the dimer of bromonitrile oxide becomes the main product, and the yield of the target product decreases. The base used to generate nitrile oxide is desirably potassium bicarbonate, and the reaction solvent is tetrahydrofuran (TH
It is also necessary to use an ether type such as F), dioxane, dimethoxyethane, etc., and to have an appropriate amount of water.

Halonitrile oxide can be obtained by adding glyoxylic acid oxime to N-chlorosuccinimide (NCS), t-butyl hypochlorite, N-bromosuccinimide (NB
A halogenating agent such as S) is reacted in an ether-based solvent and is generated in the presence of a base, but is usually subjected to the next reaction without being taken out.

Production method 2 Method for halogenating 3-isoxazolidone

[0016]

Embedded image

(In the formula, X has the same meaning as described above.)

The reaction can be carried out without solvent by using phosphorus pentachloride or phosphorus oxychloride as a chlorinating agent for 3-isoxazolidone, or phosphorus tribromide as a brominating agent. When a solvent is used, a solvent that does not react with the halogenating agent, for example, an aromatic solvent such as toluene or chlorobenzene, or a halogenated hydrocarbon such as carbon tetrachloride is desirable.

In the present invention, after completion of the reaction, the desired product can be obtained by performing ordinary post-treatment. The structure of the compound of the present invention was determined from IR, NMR, MS and the like.

[0020]

Next, the present invention will be described more specifically with reference to examples.

Example 1 Preparation of 3-chloro-2-isoxazoline

[0022]

Embedded image

A solution prepared by dissolving 26.7 g of oxime glyoxylate in 300 ml of dimethoxyethane was added with NC at room temperature.
S80.1 g was added, and the mixture was heated under reflux for 20 minutes. Thereafter, the reaction mixture was cooled to room temperature and potassium hydrogen carbonate 120
g and 6 ml of water are added, the solution is transferred to a 1 l glass autoclave vessel, filled with ethylene,
Stirred for hours. The insolubles were filtered, the filtrate was poured into ice water, extracted with diethyl ether, and the organic layer was washed with water.
It was dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the remaining oil was distilled under reduced pressure to give 3-chloro-.
17.7 g of 2-isoxazoline were obtained. b. p. 76 ° C./27 mmHg, n _D ^24.3 : 1.462
8

Example 2 Preparation of 3-chloro-2-isoxazoline

[0025]

Embedded image

A mixture of 0.6 g of 3-isoxazolidone and 1.4 g of phosphorus pentachloride was stirred at 60 ° C. for 1 hour. afterwards,
The reaction mixture was cooled to room temperature and then poured into ice water,
After extraction with diethyl ether, the organic layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the remaining oil was distilled under reduced pressure to give 3-chloro-2.
0.3 g of isoxazoline was obtained. The product was identical to the product obtained by the method of Example 1.

Example 3 Preparation of 3-bromo-2-isoxazoline

[0028]

Embedded image

26.7 g of glyoxylic acid oxime was dissolved in 300 ml of dimethoxyethane, and 90 ml of water was added.
After adding 106.8 g of N-bromosuccinimide under cooling and stirring at room temperature for 20 minutes, 120 g of potassium hydrogen carbonate was added over 30 minutes while blowing ethylene gas at room temperature.
The solution was stirred at room temperature for 4 hours. The insolubles were filtered, the filtrate was poured into ice water and extracted with diethyl ether,
The organic layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the remaining oil was distilled under reduced pressure to obtain 13.4 g of 3-bromo-2-isoxazoline. b. p. 101 ° C./30 mmHg, n _D ^18.9 : 1.53
53

[0030]

According to the present invention, 3-unsubstituted
Halo-2-isoxazolines can be provided. The isoxazoline ring is an extremely important compound as a precursor because amino alcohols and hydroxy ketones are generated by hydrolysis upon reduction. It is also known as a physiological activity expression skeleton and has many examples. Furthermore, WO96 / 2
No. 6,206, WO 98/31681, and examples of use as herbicides and Japanese Patent Application Laid-Open No. 1-249790 are known as insecticides and acaricides.

Continued on the front page (72) Inventor Tetsushi Oguchi 345 Takada, Odawara-shi, Kanagawa Japan Soda Co., Ltd. Odawara Research Laboratories F term (reference) 4C056 AA01 AB01 AC01 AD01 AE02 AF04 FA01 FB03 FC01

Claims (3)

[Claims] 1. A compound of the general formula (1) (Wherein, X represents a chlorine atom, a bromine atom or an iodine atom.) 3-halo-2-isoxazoline. 2. The following formula: (Wherein, X represents the same meaning as described above), wherein ethylene is reacted with halonitrile oxide represented by the formula (1), wherein 3-halo-2-isoxazoline is produced. 3. A process for producing 3-halo-2-isoxazoline, which comprises reacting 3-isoxazolidone with a chlorinating agent, a brominating agent or an iodinating agent.