JP2003335735A - Method for producing perfluoroisopropylanilines - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing perfluoroisopropylanilines useful as an intermediate. <P>SOLUTION: The method for producing the perfluoroisopropylanilines represented by formula (I) comprises reacting perfluoroisopropyl chloride or perfluoroisopropyl bromide with anilines in the presence of a reaction initiator. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an industrially advantageous method for producing perfluoroisopropylanilines which are useful as intermediates for agricultural chemicals or pharmaceuticals.

[0002]

2. Description of the Related Art As a method for producing perfluoroisopropylanilines, for example, JP-A-11-3022 is known.
The methods disclosed in Japanese Patent No. 33 and Japanese Patent Application Laid-Open No. 2001-122836 are known. Further, as a method of using perfluoroalkyl chloride, J. Fluorine Chemistry (J. Fluorine Chem
(Mistry), 111 , 107 (2001).

[0003]

However, Japanese Patent Laid-Open Nos. 11-302233 and 2001-1228.
In the method disclosed in Japanese Patent Publication No. 36-36, expensive perfluoroalkyl iodide is used as a raw material, and it cannot be said to be advantageous as an industrial production method. In addition, the Journal of Fluorine Chemistry (J. Fluorine Chem
(Istry), 111 , 107 (2001) does not describe branched perfluoroalkyl chlorides, and the solvent is limited to dimethyl sulfoxide.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted extensive studies to solve the above problems and provide an industrially advantageous method for producing perfluoroisopropylanilines. II) by reacting perfluoroisopropyl chloride or perfluoroisopropyl bromide with an aniline represented by the general formula (III) in the presence of a reaction initiator. The present invention has been completed by finding that fluoroisopropylanilines can be produced.

That is, the present invention has the general formula (II):

[Chemical 4] (Wherein X represents a chlorine atom or a bromine atom) and perfluoroisopropyl chloride or perfluoroisopropyl bromide represented by the general formula (III):

[Chemical 5] (In the formula, R ¹ , R ² , R ³ and R ⁴ may be the same or different, and are a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkyl group, a halo C ₁ -C ₆ alkyl group, C ₁ -C ₆ alkoxy groups or halo C ₁
~C shows a ₆ alkoxy group. ) The aniline represented by the formula (I) is reacted in the presence or absence of a reaction initiator.

[Chemical 6] (In the formula, R ¹ , R ² , R ³ and R ⁴ are the same as above.) The present invention relates to a method for producing perfluoroisopropylanilines.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The reaction of the present invention is illustrated below.

[Chemical 7] (In the formula, X, R ¹ , R ² , R ³ and R ⁴ are the same as described above.) That is, in the formula (II), perfluoroisopropyl chloride or perfluoroisopropyl bromide and the formula (III) By reacting with the aniline represented by the reaction in the presence of a reaction initiator and a base, or in the presence or absence of an inert solvent, the perfluoroisopropylaniline represented by the general formula (I) can be produced.

As the reaction initiator, a reducing agent or light irradiation can be used. Examples of the reducing agent include dithionite salts such as sodium dithionite and potassium dithionite, and zinc-sulfite water. It can be used, and the amount used is not particularly limited, but is in the range of 1/100 to 2 times, preferably 1/10 times the mol of the compound represented by the general formula (II) or (III). To 1.2 times the molar range. The light source used for light irradiation is not particularly limited as long as it has sufficient energy to start the reaction, and for example, a high pressure mercury lamp or the like can be used. The reducing agent or the light irradiation as the reaction initiator may be used alone or in combination of two or more.

As the base, an inorganic base or an organic base can be used. Examples of the inorganic base include alkali metal carbonates such as sodium hydrogen carbonate, sodium carbonate and potassium carbonate, alkali metals such as sodium hydroxide and potassium hydroxide. As the inorganic bases such as metal hydroxide and the organic bases, organic bases such as triethylamine and 4-dimethylaminopyridine can be used. The amount of the base used may be appropriately selected and used in the range of 0.5 times to 5 times the mol of the compound represented by the general formula (II) or (III). Any inert solvent may be used as long as it does not significantly inhibit the progress of the reaction, and examples thereof include ether solvents such as diethyl ether and t-butyl methyl ether, ester solvents such as ethyl acetate, halogen solvents such as dichloroethane, and water. Etc. can be used, and these inert solvents can be used alone or in combination of two or more kinds.

Although depending on the substituents of the raw materials and the conditions, use of an inert solvent such as a nonpolar solvent has good reaction selectivity and is often a more preferable condition. When a non-polar solvent is used, the extraction operation can be performed as it is in the reaction system or by adding an appropriate amount of the non-polar solvent, which is advantageous in terms of production cost. It is also possible to carry out the reaction in a two-phase system by combining water and a non-polar solvent as an inert solvent, and it is possible to appropriately select and use from the above-mentioned inert solvent, and to use a two-phase system of water and an inert solvent. Gives better results. It is also possible to use a phase transfer catalyst.

Examples of the phase transfer catalyst include quaternary ammonium salts such as tetrabutylammonium hydrogensulfate and tetrabutylammonium bromide, organic phosphorus salt compounds such as tetrabutylphosphonium bromide,
Alkyl polyether alkylamine compounds such as tris (methoxyethoxyethyl) amine can be used. A phase transfer catalyst is not necessary, but it may give better results in some cases. The amount of the phase transfer catalyst used is not particularly limited, but is not limited to the general formula (II) or (II
1/500 times by mol to 2 times the compound represented by I)
It is in the range of double mole, preferably 1/50 times mole to equimolar range. The reaction temperature may be 0 ° C. to the boiling point range of the solvent used under the conditions. It is advantageous for industrial production to carry out the heating at a temperature in the range of 0 ° C to 50 ° C.

The reaction time varies depending on the reaction conditions, but is usually several minutes to several tens hours, preferably about 30 minutes to 24 hours. In this reaction, after the completion of the reaction, the desired product can be produced by isolating the desired product from the reaction system by a conventional method and performing purification or the like if necessary. Since this reaction is an equimolar reaction, the compound represented by the general formula (II) or (III) may be used in an equimolar amount, but either one may be used in excess. The produced perfluoroalkylanilines can be stably stored in the presence of an inorganic alkali metal salt or an alkaline earth metal salt. As the inorganic alkali metal salt or alkaline earth metal salt, potassium carbonate, sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, calcium hydroxide or the like can be used. The effect is also effective, for example, when distilling and purifying crude perfluoroalkylanilines.

[0012]

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In displaying physical properties, ¹ H NMR (CDCl3 /
TMS) δ is the delta value of proton nuclear magnetic resonance observed in deuterated chloroform solvent using tetramethylsilane as a standard substance. Example 1. Preparation of 2-methyl-4-heptafluoroisopropylaniline. 2-toluidine 1.16 g (10.8 mmol), heptafluoroisopropyl chloride 4.0 g (20 mmol), sodium dithionite 2.2 g (13 mmol), sodium hydrogencarbonate 1.1 g (13 mmol) in a 100 ml autoclave. And 0.4 g (1.2 mmol) of tetrabutylammonium hydrogen sulfate were sequentially added to a mixed solution of 20 ml of water and 20 ml of t-butyl methyl ether, and the mixture was stirred at room temperature for 8 hours. After separating the organic layer, the aqueous layer was extracted with 20 ml of ethyl acetate, and the organic layers were combined and washed successively with 2N aqueous hydrochloric acid, 5% aqueous sodium carbonate solution and saturated brine. The organic layer was dried over magnesium sulfate, filtered, and the organic solvent was distilled off under reduced pressure to obtain the desired product. (Yield 25%) Physical property ¹ HNMR (CDCl3 / TMS) δ: 2.20 (d.3H), 3.86 (bs.2H), 6.71 (d. 1H), 7.25 (d.1H), 7.26 (s.1H) .

Example 2. Preparation of 2-methyl-4-heptafluoroisopropylaniline. The reaction was performed in the same manner as in Example 1 except that heptafluoroisopropyl chloride was replaced with heptafluoroisopropyl bromide. The target product was obtained by performing the same post-treatment as in Example 1. (Yield 3
2%)

Example 3 Preparation of 5-chloro-4-heptafluoroisopropyl-2-methylaniline. It was produced in the same manner as in Example 1.
(Yield 28%) Physical property ¹ HNMR (CDCl _{3 /} TMS) δ: 2.15 (s, 3H), 4.00 (bs, 2H),
6.75 (s.1H), 7.19 (s, 1H) Example 4 3-Fluoro-4-heptafluoroisopropyl-2-
Manufacture of methylaniline. It was produced in the same manner as in Example 1. (Yield 26%) Physical property ¹ HNMR (CDCl _{3 /} TMS) δ: 2.08 (d, 3H), 4.00 (bs, 2H),
6.52 (d, 1H), 7.20 (t, 1H) Example 5 Preparation of 2,5-dimethoxy-4-heptafluoroisopropylaniline. It was produced in the same manner as in Example 1. (Yield 35%) Physical property ¹ HNMR (CDCl _{3 /} TMS) δ: 3.74 (s.3H), 3.82 (s.3H), 4.
11 (bs.2H), 6.35 (s.1H), 6.91 (s1H), 7.18 (d.1H)

[0015]

Industrial Applicability According to the present invention, it is possible to provide an industrially advantageous method for producing perfluoroisopropylanilines which are useful as agricultural chemical intermediates.

Claims (2)

[Claims] 1. A compound represented by the general formula (II): (Wherein X represents a chlorine atom or a bromine atom) and perfluoroisopropyl chloride or perfluoroisopropyl bromide represented by the general formula (III): (In the formula, R ¹ , R ² , R ³ and R ⁴ may be the same or different, and are a hydrogen atom, a halogen atom, a C ₁ -C ₆ alkyl group, a halo C ₁ -C ₆ alkyl group, C ₁ -C ₆ alkoxy groups or halo C ₁
~C shows a ₆ alkoxy group. ) Is reacted with an aniline represented by the formula (I :) in the presence of a reaction initiator and a base: A method for producing perfluoroisopropylanilines represented by: 2. The reaction is carried out in the presence of a two-phase system of water and one or more solvents selected from ether solvents, ester solvents such as ethyl acetate, dichloroethane or halogen solvents as the inert solvent. The method for producing the perfluoroisopropylanilines according to claim 1.