JPS62114962A - Tetrahydrophthalimide derivative and production thereof - Google Patents

Abstract

NEW MATERIAL:2-(5-Bromo-4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2-H- isoindole-1,3-dione. USE:Intermediate for the production of a herbicide (tetrahydrophthalimide derivative). PREPARATION:The objective compound can be produced by reacting 5-bromo-4- chloro-2-fluoroaniline with 3,4,5,6-tetrahydrophthalic anhydride in a solvent such as acetic acid, propionic acid, butyric acid, etc., at a temperature between 100 deg.C and the boiling point of the solvent for 2-10hr.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 2-(5-bromo-4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-
This invention relates to isoindole-1,8-dione (hereinafter referred to as the compound of the present invention) and its production method.

The compound of the present invention has a herbicidal effect, and has the general formula CI)C, in which R represents a hydrogen atom, an alkyl group, or a fe-nyl group. ] This compound is useful as an intermediate in the production of the tetrahydrophthalimide derivative shown below.

The present inventors investigated a method for producing a compound represented by the general formula CI) having herbicidal activity, and found that the compound of the present invention, 2-(5-bromo-4-chloro-2-fluorophenyl)-4as- 6m7-tetrahydro-2H-isoindole-1°8-dione is important as an intermediate for the compound represented by the above general formula CI), and the compound of the present invention contains 5-bromo-4-chloro-2-fluoroaniline. The inventors have discovered that it can be advantageously produced by reacting with 3,4.5,6-tetrahydrophthalic anhydride, leading to the present invention.

The method for producing the compound of the present invention will be explained below.

In the production method of the present invention, the amount of reagents used for the reaction is 5
-1.0 to 1.1 equivalents of 8°4.5,6-tetrahydrophthalic anhydride per equivalent of -bromo-4-chloro-2-fluoroaniline. As the solvent used in the reaction, for example, acetic acid, propionic acid, butyric acid, etc. are used.

In the present invention, the reaction temperature and reaction time are usually in the range of 100 DEG C. to the boiling point of the solvent and in the range of 2 to 10 hours, respectively, to sufficiently achieve the purpose.

After the reaction is complete, water is added to the reaction solution, and the precipitated crystals are
Alternatively, the desired 2-(5-bromo-4 -chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione can be obtained.

By reacting the compound of the present invention obtained by the production method of the present invention with an acetylene derivative, a compound having a herbicidal effect represented by the general formula (1) can be obtained.

Note that 5-bromo-4-chloro-2-fluoroaniline, which is a raw material for the compound of the present invention, can be obtained by the following manufacturing method.

! 1, 1 equivalent of 2-chloro-4-fluoroaniline.
After diazotization by acting with 0 to 2.0 equivalents of a diazotizing agent, acting with 1.0 to 2.0 equivalents of a brominating agent such as cuprous bromide in an aqueous solution such as hydrobromic acid. 1-bromo-2-chloro-4-fluorobenzene is obtained by bromination. In the above reaction, the reaction temperature and reaction time are usually in the range of -5 to 5°C for diazotization and 0.5 to 5°C, respectively.
The purpose can be sufficiently achieved within the range of 3 hours, and the bromination is usually carried out at a temperature of 20 to 70°C and a time of 1 to 5 hours, respectively.

In the next step, 1-bromo-2-chloro-4- obtained above
1-Bromo-2-chloro-4-fluoro-5- is produced by reacting 1 equivalent of fluorobenzene with 1 equivalent or more of sulfuric acid, preferably concentrated sulfuric acid, and 1.0 to 1.2 equivalents of nitric acid, preferably fuming nitric acid. Nitrobenzene is obtained.

In the above reaction, the reaction temperature and reaction time are usually in the range of -10 to 20°C and in the range of 1 to 10 hours, respectively, to sufficiently achieve the purpose.

Furthermore, for each 1-bromo-2-chloro-4-fluoro-5-nitrobenzene obtained above, 8 to
5-Bromo-4-chloro-2-fluoroaniline is obtained by reacting with 80 equivalents, preferably 5 to 20 equivalents of a reducing agent such as iron powder. The reaction temperature is usually 60-1
The temperature is 20°C, and the reaction time is usually 1 to 20 hours, which is sufficient to achieve the purpose.

This reaction is carried out, for example, in an aqueous acetic acid solution, if necessary, in the presence of an auxiliary solvent such as ethyl acetate.

In addition, 2-chloro-4-fluoroaniline, which is a raw material compound, is described in Finger et al., J. Am.

It can be produced by the production method described in Chem, Soc, 81.94 (1959).

The present invention will be explained in more detail with reference to Examples and Reference Examples below.

Example 5 - Bromo-4-chloro-2-fluoroaniline 5,4
f, 3.71 ml of 3,4.5,6-tetrahydrophthalic anhydride were suspended in 70 ml of acetic acid and heated under reflux for 5 hours. After the reaction mixture was cooled, water was added and extracted with ethyl acetate. The extract was washed with water, dried, and concentrated to give 2-(5-
Bromo-4-chloro-2-fluorophenyl)-4,5
,6,7-tetrahydro-2H-isoindole-1,
8-geo:15,Of was obtained. m, p.

140.2°C Reference Example 1 2-chloro-4-fluoroaniline 58f was dissolved in concentrated sulfuric acid 12
Dissolve in a mixture of 0y and 160 ml of water and heat to -5℃~
A solution of sodium nitrite 281 in 100 ml of water was added at 0''C and stirred for 20 minutes at the same temperature.

Excess nitrous acid in the reaction solution was removed by adding sulfuric acid to the reaction solution until the coloring of the potassium iodide starch paper disappeared. % hydrobromic acid aqueous solution (500 ml) at room temperature, and the mixture was stirred at 80-40°C for 80 minutes. This reaction mixture was extracted with ether, and the ether layer was washed with water, dried, concentrated, distilled, and 1-bromo-2-chloro-
4-fluorobenzene 76f was obtained. b, p, 62.0
~62.8°C/12 Hg Reference Example 2 219 1-bromo-2-chloro-4-fluorobenzene obtained above was dissolved in 1240 ml of concentrated sulfur. This was cooled to 0°C to 10°C, and fuming nitric acid (d=1.5
2) Heat a mixture of 3,2f and concentrated sulfuric acid 5yxt to 0°C.
It was gradually added dropwise at 5°C and stirred at the same temperature for 80 minutes. The reaction mixture was poured into ice water and extracted with ether. The extract was washed with water, dried, and concentrated to give 1-bromo-2-chloro-4-
14.31 fluoro-5-nitrobenzene was obtained. m,
p, 65.0-65.5°C Reference Example 8

Claims (2)

[Claims] (1) 2-(5-bromo-4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-isoindole-1,8-dione (2) 2-(5-bromo-4-chloro-2- Method for producing (fluorophenyl)-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione.