JPS61229839A - Halogenoketone compound and production thereof - Google Patents

Abstract

NEW MATERIAL:A halogenoketone compound expressed by the formula (X represents Cl, Br). EXAMPLE:1,4-Dichloro-3,3,4-trimethyl-2-pentanone. USE:Useful as an intermediate for synthesis of an acid component of pyrethroid based insecticidal and acaricidal compounds such as fenpropathrin. PREPARATION:3,3,4-Trimethyl-4-chloro-2-pentanone is reacted with a chlorinating agent or brominating agent to obtain the compound expressed by the formula. As for the chlorinating agent or brominating agent, chlorine, sulfuryl chloride, phosphorus pentabromide, etc. are used, and the molar amount thereof to be used is usually 0.7-1.5mol based on 1mol above-mentioned starting raw material. The reaction temperature is within O-60 deg.C range. The starting raw material, 3,3,4-trimethyl-4-chloro-2-pentanone, is a novel compound, and is synthesized by reacting 2,3-dimethyl-2-butene with acetyl chloride in the presense of a Lewis acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula (1) [wherein, X represents a chlorine atom or a bromine atom]. ] The halogenoketone compound (hereinafter referred to as the compound of the present invention) and its production method include 8゜8.4-) dimethyl-4-chloro/I/-2-pentanone as a chlorinating agent or a brominating agent. Regarding the method for producing the compound of the present invention by reaction: The present inventors have conducted various studies on methods for synthesizing the acid component of pyrethroid insecticidal and insecticidal compounds, such as fenprobasrin represented by the formula. As a result, it was discovered that the compound of the present invention represented by the above formula (I) can serve as an important synthetic intermediate thereof, and that the compound has a compound of 8.8°4-trimethyl-4-chloro/L/ −
We have discovered that the present invention can be produced industrially by reacting 2-pentanone with a chlorinating agent or a brominating agent. O is an extremely useful intermediate because it can easily be treated to form a compound represented by formula (5), which is the acid component of the pyrethroid insecticidal and acaricidal compound. Describing the method for producing the invention compound O In the production method of the present invention, examples of the chlorinating agent or brominating agent used include chlorine, bromine, sulfuryl chloride, phosphorus pentabromide, N-glomsuccinimide, and the like. The amount used is 8.8゜4-trimethy/l/-4-chlor/'I/
It is usually 0.7 to 1.5 times the mole per mole of 2-pentanone.0 Examples of solvents that can be used include water, methanol, acetic acid, dichloroethane, chloroform, etc. ◇Reaction temperature is usually 0°C ~60°C), and the reaction time may vary depending on the type of solvent chlorinating agent or brominating agent used and the reaction temperature, but is usually 1 to 24 hours. It is also possible to add a dehydrohalogenating agent such as hydrogen chloride or hydrogen bromide in a catalytic amount to the reaction system, amines, lime carbonate, or potassium chlorate. 8, 8.4-) Rimethi A/-
4-chloro-2-pentanone is a new compound; 2.
8-dimethyA/-2-butene in the presence of a Lewis acid,
It can be obtained efficiently by reacting with acetyl chloride.

In this reaction, the Lewis acids used include metal chlorides such as ferric chloride, zinc chloride, aluminum chloride, stannic chloride, and antimony trichloride, and the amount used is 2, 8-dimethy, A/-2-butene per moμ
The reaction temperature ranges from -50°C to IJe/L/, although it can vary depending on the amount of Lewis acid used.
-80°C, usually -20°C to 10°C is preferred from the viewpoint 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 generally the reaction proceeds very quickly, so it is within 10 hours, preferably within 2 hours.

In addition, the amount of acetyl chloride used is usually in the range of 1.0 to 1.5 mol per 1 mol of 2,8-dimethyl-2-guten. , for example, an inert solvent such as dichloroethane or dichloroethane may be used as the reaction solvent. Next, the present invention will be explained in more detail with reference to Examples and Reference Examples.

Example 1 8.8.4-trimethyA/-4-chloro/L'-2-pentanone8. Dissolve Of in 80JTI of dichloromethane, add 2 drops of synchrohexylamide, and then add 10J of sulfur chloride. Of was added dropwise at 0°C. After the dropwise addition, the reaction solution was stirred at 20°C for 24 hours, and the reaction solution was poured into ice water and extracted with dichloromethane/methane. The dichloroethane layer was washed with water, dried over magnesium sulfate, and the concentrated residue was purified by silica gel column chromatography. Attached to 6
．． 12 1,4-dichloro-8,8,4-trimethyl-
Refractive index 1.4778 (25.5℃) NMR data (
δ value, CDCJ, ) 1.37 (s, 6H), 1.62 (a, 6H), 4.5
5(s, 2H) Example 2 8.8.4-) Rimethyl 1L/-4-chloro/L'-2-pentanone 2.2t was dissolved in methano-fiy 15 mJ and bromine 2.50F at 20°C. (1,2 times Mo/S/) was added dropwise and stirred for 1 hour. The reaction solution was poured into ice water and extracted twice with dichloromethane. Ziclo IL/) 1 Tan m
was dried with anhydrous magnesium sulfate and concentrated to obtain the desired 1-bromo-4-chloro/L/-8,8,4-)rimethyl/I/-
2-pentanone (in the general formula (1) above, substituent X
A halogenoketone compound (8.11 in which is a bromine atom) was obtained (yield: 96 g6).

Refractive index 1.5000 (21.5℃) NMR (δ value,
CDCJ, ) 1.87 (a, 6H), 1.59 (s, 6H), 4.8
0(s, 2H) Reference Example 1 2.8-dimethy/I/-2-butene 20. Of(0,
After dissolving 288 f/I/) in 50 mA of dichloroethane, 20.5 f of acetyl chloride (0,261
-e/Iz) and then cooled to 0°C while stirring under water cooling.
Then, zinc chloride 82F (0,0285 mol'v) was added little by little.At this time, an increase in the internal temperature was observed, but the temperature of the reaction solution was kept below 6°C. After stirring for an additional 80 minutes at 0 to 6°C, the reaction solution was poured into ice water and the separated 0 dichloromethane layer was washed with water, dried over magnesium sulfate, concentrated (~80°C/70 mHf), and a pale residue was obtained. Yellow oil/l/29. Yield of 75%).

This compound was confirmed to be rimethino v-4-chloro/I/-2-pentanone from its NMR spectrum μ. It is preferable that only the low boiling fraction be distilled off at 156 smHr.

NMR data (δ value, CDCjs) 1.80 (s,
6H), 1.60 (m, 6H), 2.28 (s, 8H)
Reference example 2 1.4-diku'CIIV-8,L4-)rimethi/L/-
2-Pentanone 2.72% Tetotsuhydrofone 10mh
The o solution was added dropwise to a solution consisting of 6 of sodium hydroxide, 50 mj of water, and 86 ml of tetrahydrofuran at 4 G°C. After the dropwise addition, the solution was further stirred at 25°C for 12 hours.
The reaction solution was poured into ice water, extracted with ether to remove the neutral part, the aqueous solution was acidified with hydrochloric acid, extracted twice with ether, washed the ether layer with brine, and dried over magnesium sulfate. The ether was distilled off to obtain 1.60V of white crystals (yield: 82.2%).

has a melting point of 119.8°C and has a melting point of 119.8°C.
90 (Matsui, Kitahara et al., l A
gr, Biol, ehem, vol. 81, 11
48 (1967)).

Claims (2)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, X represents a chlorine atom or a bromine atom. ] A halogenoketone compound represented by (2) General formula characterized by reacting 8,8,4-trimethyl-4-chloro-2-pentanone with a chlorinating agent or a brominating agent ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, X represents a chlorine atom or a bromine atom. ] A method for producing a halogenoketone compound.