JPH06714B2 - Halogenoketone compound and process for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has the general formula (I) [In the formula, X represents a chlorine atom or a bromine atom. ] The halogenoketone compound represented by (hereinafter, referred to as the compound of the present invention) and its production method include reacting 3,3,4-trimethyl-4-chloro-2-pentanone with a chlorinating agent or a brominating agent. The present invention relates to a method for producing the compound.

We have, for example, the formula In, such as fenpropasulin, pyrethroid insecticide, as a result of various studies on the synthesis method of the acid component of the acaricidal compound, the compound of the present invention represented by the formula (I) can be an important synthetic intermediate thereof It was also found that the compound can be produced extremely advantageously industrially by reacting 3,3,4-trimethyl-4-chloro-2-pentanone with a chlorinating agent or a brominating agent. Came to.

The compound of the present invention, as shown below, can be easily led to a compound represented by the formula (II), which is an acid component of the pyrethroid insecticide and acaricidal compound by treating with alkali hydroxide, It is a useful intermediate.

The production method of the compound of the present invention will be described below.

Examples of the chlorinating agent or brominating agent used in the production method of the present invention include chlorine, bromine, sulfuryl chloride, phosphorus pentabromide, N-promsuccinimide, and the amount thereof is 3,3. The amount is usually 0.7 to 1.5 times the mole of 1,4-trimethyl-4-chloro-2-pentanone.

Examples of the solvent that can be used include water, methanol, acetic acid, dichloromethane, chloroform and the like. The reaction temperature is usually from 0 ° C to 60 ° C, and the reaction time is usually from 1 to 24 hours, although it may vary depending on the type of the solvent chlorinating agent or brominating agent used and the reaction temperature. In order to carry out the reaction more smoothly, a catalytic amount of hydrogen chloride or hydrogen bromide may be added to the reaction system, or a dehydrohalogenating agent such as amines, lime carbonate or potassium chlorate may be added. it can.

In addition, 3,3,4-trimethyl-4-chloro-2-pentanone, which is a raw material of the above-mentioned production method, is a novel compound, and 2,3-dimethyl-2-butene is mixed with acetyl chloride in the presence of Lewis acid. It can be efficiently obtained by reacting.

In the reaction, examples of the Lewis acid used include ferric chloride, zinc chloride, aluminum chloride, stannic chloride, metal chlorides such as antimony trichloride, and the amount thereof is 2,3-dimethyl- 0.002 to 1 mol of 2-butene
It is in the range of 1 mol to 1 mol. The reaction temperature may vary depending on the amount of Lewis acid used, but is -50 ° C to 30 ° C,
Usually, the range of −20 ° C. to 10 ° C. is preferable in terms of yield.

The reaction time in this reaction may vary depending on the type and amount of Lewis acid used and the reaction temperature, but is generally 10 hours or less, and more preferably 2 hours or less because the reaction generally proceeds extremely quickly.

The amount of acetyl chloride used is usually in the range of 1.0 to 1.5 mol per 1 mol of 2,3-dimethyl-2-butene.

In order to carry out the reaction more smoothly, an inert solvent such as dichloromethane or dichloroethane can be used as the reaction solvent.

Next, the present invention will be described in more detail with reference to Examples and Reference Examples.

Example 1 8.0 g 3,3,4-trimethyl-4-chloro-2-pentanone
Was dissolved in 30 ml of dichloromethane, 2 drops of dicyclohexylamine was added thereto, and then sulfuryl chloride 1 was added.
0.0 g was added dropwise at 0 ° C. After the dropping, the mixture was stirred at 20 ° C. for 24 hours, poured into ice water, and extracted with dichloromethane. The dichloromethane layer was washed with water, dried over magnesium sulfate, and concentrated. The concentrated residue was subjected to silica gel column chromatography to give 6.1 g of 1,4-dichloro-
3,3,4-Trimethyl-2-pentanone (a compound in which the substituent X in the formula (I) is a chlorine atom) was obtained as a pale yellow oil.

Refractive index 1.4773 (25.5 ° C) NMR data (δ value, CDCl ₃ ) 1.37 (s, 6H), 1.62 (s, 6H), 4.55 (s, 2H) Example 2 3,3,4-trimethyl-4-chloro -2-pentanone 2.2g
Was dissolved in 15 ml of methanol, 2.50 g (1.2 times mol) of bromine was added dropwise at 20 ° C., and the mixture was stirred for 1 hour. The reaction solution was poured into ice water and extracted twice with dichloromethane. The dichloromethane layer was dried over anhydrous magnesium sulfate and then concentrated to obtain the desired 1-
3.1 g of bromo-4-chloro-3,3,4-trimethyl-2-pentanone (a halogenoketone compound in which the substituent X in the general formula (I) is a bromine atom) was obtained (yield 96%).

Refractive index 1.5000 (21.5 ° C.) NMR (δ value, CDCl ₃ ) 1.37 (s, 6H), 1.59 (s, 6H), 4.30 (s, 2H) Reference example 1 2,3-Dimethyl-2-butene 20.0 (0.238 mol) was dissolved in 50 ml of dichloroethane and acetyl chloride was added to it.
20.5 g (0.261 mol) was added, and 3.2 g (0.0235 mol) of zinc chloride was added little by little at 0 ° C while stirring under ice cooling.
At this time, an increase in internal temperature was observed, but the temperature of the reaction solution was adjusted to 5
The temperature was kept below ℃. After stirring at 0 to 5 ° C for 30 minutes, the reaction solution was poured into ice water and separated. The dichloroethane layer was washed with water, dried over magnesium sulfate, and then concentrated (~ 80 ° C
/ 70 mmHg) to obtain 29.0 g of a pale yellow oil as a residue (yield 75%).

From its NMR spectrum, this was confirmed to be the desired 3,3,4-trimethyl-4-chloro-2-pentanone.

Although this compound has a boiling point of 105 to 110 ° C / 55 mmHg, it tends to cause a partial dehydrochlorination reaction during the distillation operation to lower the yield, so a low boiling fraction is distilled off during distillation. It is preferable to keep it only.

NMR data (δ value, CDCl ₃ ) 1.30 (s, 6H), 1.60 (s, 6H), 2.28 (s, 3H) Reference Example 2 1,4-dichloro-3,3,4-trimethyl-2-pentanone
A solution of 2.7 g of 10 ml of tetrahydrofuran was added dropwise at 40 ° C. to a solution of 6.0 g of sodium hydroxide, 50 ml of water and 35 ml of tetrahydrofuran. After the dropping, the mixture was further stirred at 25 ° C. for 12 hours, poured into ice water, extracted with ether to remove the neutral part, the aqueous solution was acidified with hydrochloric acid, and extracted twice with ether. The ether layer was washed with brine and dried over magnesium sulfate, and the ether was distilled off to obtain 1.60 g of white crystals (yield 82.2%).

It has a melting point of 119.8 ° C and was synthesized from ethyl diazoacetate and 2,3-dimethyl-2-butene 2,2,3,3-
Consistent with tetramethylcyclopropane-1-carboxylic acid. (Matsui, Kitahara et al., Agr. Biol. Chem. 31, 1143 (196
7)).

Claims (2)

[Claims] 1. A general formula [In the formula, X represents a chlorine atom or a bromine atom. ] The halogenoketone compound shown by these. 2. 3,3,4-Trimethyl-4-chloro-2
-General formula characterized by reacting pentanone with a chlorinating or brominating agent [In the formula, X represents a chlorine atom or a bromine atom. ] The manufacturing method of the halogenoketone compound shown by these.