JPS6064959A - Production of tetrahydrophthalimide derivative - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a herbicidally active compound easily in high yield and purity, by chlorinating N-2'-fluoro-5'-isopropoxyphenyl-3,4,5,6-tetrahydrophthalimide as a raw material. CONSTITUTION:N-2'-Fluoro-5'-isopropoxyphenyl-3,4,5,6-tetrahydrophthali mide as a raw material is chlorinated with sulfuryl chloride or Cl2 in a solvent in the presence of a dehydrohalogenating agent, e.g. dicyclohexylamine, at 10-100 deg.C for 1-10hr to afford N-2'-fluoro-5'-isopropoxyphenyl-3,4,5,6-tetrahydrophthalimide. The above-mentioned raw material is obtained by reacting 2-fluoro-5- aminoacetanilide with NaNO3, hydrolyzing the resultant compound, and reacting the hydrolysis product with 3,4,5,6-tetrahydrophthalic anhydride, and finally with an isopropyl halide of the formula (X is Cl or Br, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing N-2'-fluoro-5'-isopropoxyphenyl-8,4,5,6-titrahydrophthalimide (hereinafter referred to as an imide compound).

The above-mentioned imide compound is known as a compound having herbicidal activity (Japanese Unexamined Patent Publication No. 168365/1983).

As a method for producing the imide compound, the method described in the above publication in which 4-chloro-2-fluoro-5-isopropoxyaniline and 8,4,5,6-titrahydrophthalic anhydride are reacted has been used so far. It has been known.

However, in this method, the raw material 4-chloro-2-
In terms of the number of steps and operations required to obtain fluoro-5-isopropoxyaniline, this method cannot necessarily be said to be a sufficient method for industrial production.

As a result of repeated studies on a method for producing the imide compound industrially more advantageously, the present inventors discovered that N-2'-fluoro-5'-isopropoxyphenyl-3,4,5,6
- It has been found that the target imide compound can be obtained in a high yield and in high purity by chlorinating titrofuclimide, leading to the present invention.

That is, the present invention provides a method for producing the above imide compound by chlorinating N-2'-fluoro-5'-isopropoxyphenyl-8,4,5,6-titrahydrophthalimide.

The method of the present invention will be explained below.

The process of the invention typically involves N-2'-fluoro-5'
-isopropoxyphenyl-8,4,5,6-titrahydrophthalimide and 1 to 7 equivalents of sulfuryl chloride or chlorine in a solvent in the presence of 0.0001 to 1 equivalent of a dehydrohalogenating agent. , 1~ at 10°~100°C
This is carried out by reacting for 10 hours.

In the above reaction, solvents that can be used include aliphatic hydrocarbons such as hexane, heptane, ligroin, petroleum ether, chloroform, carbon tetrachloride, digloroethane,
Halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorethylene, and tetrachlorethylene; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, and ethylene glycol dimethyl ether; esters such as ethyl acetate and butyl acetate; and nitrides such as nitrobenzene. , tertiary amines such as pyridine, triethylamine, tributylamine, N
, acid amides such as N-dimethylformamide, sulfur compounds such as dimethyl sulfoxide and sulfolane, or mixtures thereof.

Examples of the dehydrohalogenating agent include organic bases such as pyridine, triethylamine, N,N-diethylaniline, and dicyclohexylamine, and inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

If necessary, the desired imide compound can be obtained by purification by operations such as chromatography and recrystallization.

Note that the raw material compound for the above method can be efficiently produced, for example, by the following method.

That is, 2-fluoro-5-aminoacetanilide and 1 to 2 equivalents of sodium nitrite were heated at 0 °C in a solvent such as sulfuric acid, hydrochloric acid, water, or a mixture thereof.
C. for 5 minutes to 5 hours to give its diazonium salt, which is hydrolyzed in dilute sulfuric acid at 90 DEG -180 DEG C. to give 3-amino-4-fluorophenol. Then the compound and 1
~1.5 equivalents of 8.4.5.6-titrahydrophthalic anhydride, a fatty acid such as acetic acid, an acid amide such as N,N-dimethylformamide.

Sulfur compounds such as dimethyl sulfoxide and sulfolane,
100 to 120 in water or a mixed solvent of these
By reacting at ℃ for 1 to 10 hours, N-2'-
Fluoro-5'-hydroxyphenyl-8,4,5,6
- Obtain titrahydrophthalimide.

Next, the compound and 1 to 2 equivalents thereof of the general formula [wherein, X represents a chlorine atom, a bromine atom, or an iodine atom] are prepared. ] Isopropyl halide represented by: aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as benzene, toluene, xylene, halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, oxane, tetrahydrofuran, ethylene glycol dimethyl ether, etc. ether,
Acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, ketones such as cyclohexanone, esters such as ethyl acid, butyl acetate, nitrites such as nitrobenzene, acetonitrile, isobutyronitrile, nitrile, pyridine, triethylamine, N, N-diethyl Aniline, tertiary amines such as tributylamine, N,
An acid amide such as N-dimethylformamide, a sulfur compound such as dimethyl sulfoxide or sulfolane, 1 to 2 equivalents of an organic base such as pyridine, triethylamine, N,N-diethylaniline, etc. in water, etc., or a mixed solvent thereof,
Sodium hydroxide, potassium hydroxide, sodium carbonate,
N-2'-fluoro-5'-isopropoxyphenyl-8,4 is reacted at 50 to 150 °C for 0.5 to 10 hours in the presence of a dehydrohalogenating agent such as an inorganic base such as potassium carbonate. , 5,6-titrahydrophthalimide can be obtained.

Moreover, the above-mentioned 3-amino-4-fluorophenol can also be produced by the method described in US Pat. No. 4,006,185.

The present invention will be explained in more detail below using production examples and study examples.

Preparation Example I R-2'-Fluoro-5'-isopropoxyphene 4,5,6,7-titrahydrophthalimide 2y and dicyclohexylamine 0.01yrttetrachlorethylene 207! Dissolved in.

To this, sulfuryl chloride ly was added to tetrachlorethylene 5
rn1. The solution was heated to 80″C for 2 hours.
dripped. After the addition was completed, the mixture was further stirred at 80°C for 2 hours, and then extracted with ethyl acetate. After concentrating the extract, the resulting crystals were filtered to give 1.85f of N-2'-fluoro-41-chloro-5'-isopropoxyphenyl-
8,4,5,6-titrahydrophthalimide m, p
, 81-82°C Production Example 2 N-2'-fluoro-5'-isopropoxyphenyl-
1 g of 4,5,fz7-titrahydrophthalimide and 0.011 g of dicyclohexylamine to 207 g of tetrachlorethylene! It was dissolved in

Then, 17! of chlorine was added to this solution at room temperature. was blown into the mixture, and the mixture was further stirred at room temperature for 2 hours.

The reaction solution was extracted with methylene chloride, and the extract was added to the base bar,
Purified by silica gel chromatography (eluting with n-hexane/ethyl acetate), 0.9y of N-2'-fluoro-4'-chloro-5'-isopropoxyphenyl-3,
4,5,6-titrahydrophthalimide was obtained.

In.
It was stirred under water cooling. Next, a solution of 8.4 fFt sodium nitrite dissolved in 20°C of water was added dropwise to this at 5°C or below.

After the dropwise addition was completed, stirring was continued for 5 minutes at 5° C. or lower. The generated diazonium solution was dissolved in boiling dilute sulfuric acid (daughter sulfuric acid 80%
mJ and 60 g of water). Thereafter, after continuing to heat under reflux for 5 minutes, the reaction solution was cooled, and then 30%
A sodium hydroxide bath solution was added to adjust the reaction solution to pl=14. After extracting the reaction solution with ethyl rnate, the extract was concentrated, and the precipitated crystals were obtained.
-Fluorophenol was obtained.

”, p-137 to 189°C Reference example 2 3-amino-4-fluorophenol 2f and 4.5.6
．． tizF 7-titrahydrofucle aqueous anhydride 2.4f
The mixture was heated to reflux for 1 hour and then extracted with ethyl acetate. Crystals precipitated after condensation of the extract
3.31 N-2'
-Fluoro-5'-hydroxyphenyl-8,4,5,
6-titrahydrophthalimide was obtained.

m, p, 164.6"C Reference example 3 N-2'-fluoro-51-hydroxyphenyl-8,
10 g of 4,5,6-titrahydrophthalimide, 7y of isopropyl iodide, and 5.2 g of anhydrous potassium carbonate were dissolved in 100111 acetonitrile, and heated under reflux for 2.5 hours. After cooling, the reaction solution was extracted with ethyl acetate. After concentrating the extract, the precipitated t-cocrystals were poured into 9 d of N-2'-
Fluoro-5'-isopropoxyphenyl-3°4.5
．． 6-titrahydrophthalimide was obtained.

n+, p, 62.8°C

Claims (1)

[Claims] N-2'-fluoro-5'-isopropoxyphenyl-
N-2'-fluoro-4'-chloro-51-isopropoxyphenyl characterized by chlorinating 3,4,5,6-titrahydrophthalimide: 3.4.5.6-titrahydrophthalimide Manufacturing method.