JPH05286906A - Carbonic acid ester derivative and its production - Google Patents

Abstract

PURPOSE:To obtain new (2-chloro-4-fluorophenyl)ethyl carbonate, useful as an intermediate for agricultural chemical, simply, in excellent handleability, industrially and advantageously. CONSTITUTION:(2-Chloro-4-fluorophenyl)ethyl carbonate of formula I. The carbonic acid ester of formula I is obtained by reacting 2-chloro-4-fluorophenol with ethyl chlorocarbonate. The compound of formula I can be isolated by a simple operation of separating a reaction solution as an oily substance into an oil layer and a water layer. The carbonic ester derivative of formula I as an intermediate, for example, is converted through a compound of formula II to an agricultural chemical of formula III.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a compound of formula [I] which is useful as an intermediate for agricultural chemicals.

[Chemical 3] And a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a method of reacting 2-chloro-4-fluorophenol with halocarbonic acid methyl ester to obtain (2-chloro-4-fluorophenyl) methyl carbonate similar to the compound of the present invention is known. (EP-0,06
1,741 and JP-A-2-42042), it was also known to use the compound as a reaction raw material of 5-amino-2-chloro-4-fluorophenol. However, (2-chloro-4-fluorophenyl) methyl carbonate is a crystal having a melting point of 69 to 71 ° C., and is separated from the reaction mixture by filtration, washing with water or extraction with a solvent, concentration, and drying. Since it requires complicated operations, 5-
The reaction raw material of amino-2-chloro-4-fluorophenol was not industrially sufficiently satisfactory in terms of operability.

[0003]

From the above, the present inventors can produce 5-amino-2 by a simple method.
As a result of extensive studies on carbonic acid ester which can be industrially advantageously used as a reaction raw material of -chloro-4-fluorophenol, chlorocarbonic acid ethyl ester was used in place of halocarbonic acid methyl ester in the conventional method. Gives a novel ester carbonate derivative having a very low melting point, which under normal conditions can be isolated as an oily substance by the simple operation of separating the oily layer from the reaction solution, and 5-amino-2- They have found that they can be used as raw materials for chloro-4-fluorophenol in the same manner as conventional compounds, and have completed the present invention.

[0004]

That is, the present invention relates to the formula [I]

[Chemical 4] And a method for producing the same.

The present invention will be described in detail below. The carbonic acid ester derivative which is the compound of the present invention is 2-chloro-4.
-Synthesized from fluorophenol and ethyl chlorocarbonate, in the reaction, ethyl chlorocarbonate is used in 1 to 3 equivalents, preferably 1 to 2 equivalents, relative to 2-chloro-4-fluorophenol.

In this reaction, a base is usually used. As the base, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as potassium carbonate and sodium carbonate, triethylamine and pyridine are used. , N, N-diethylaniline, and other organic amines, and these bases can also be used as a mixture. The amount of these bases used is 1 equivalent to 3 times equivalent, preferably 1 to 2 times equivalent to 2-chloro-4-fluorophenol.

It is also effective to use a catalyst in the above reaction. Quaternary ammonium salts such as tetrabutylammonium bromide and benzyltriethylammonium chloride, crown ethers such as 18-crown-6 and cetyltributylphosphosnium bromide. It is also possible to use a phase transfer catalyst such as a phosphosnium salt typified by or tris (3,6-dioxaheptyl) amine (TDA-1).

This reaction is usually carried out in a water solvent. It is also possible to use an organic solvent. Reaction temperature is 0-100
℃, preferably 0 to 50 ℃. Change the pH of the reaction mixture to pH 5
It is desirable to carry out the reaction while controlling the pH to -12, preferably pH 7 to 10.

[0009]

INDUSTRIAL APPLICABILITY According to the present invention, the carbonic acid ester derivative [I] can be obtained easily and with good operability and industrially advantageously. Further, the carbonate derivative [I] obtained in the present invention is used as an intermediate, for example, in JP-A-58-3.
It can lead to the pesticide described in No. 8256.

[0010]

[Chemical 5] (Agricultural chemicals described in JP-A-58-38256)

[0011]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples. Example 1 Synthesis of (2-chloro-4-fluorophenyl) ethyl carbonate A 4-neck flask was charged with 132 g of 2-chloro-4-fluorophenol and 370 g of water, and a small amount of 37.0% sodium hydroxide aqueous solution was added to adjust the pH to 7.0. Adjusted to. After cooling this in a water bath, 102.6 g of ethyl chlorocarbonate and 102.2 g of 37.0% sodium hydroxide were added over 1 hour at a reaction temperature of 30.
It was poured in parallel so as not to exceed ℃. After the reaction solution was stirred at room temperature for 2 hours, liquid separation operation was performed, the oil layer was separated, and 195 g of (2-chloro-4-fluorophenyl) ethyl carbonate was obtained.
Got (Yield 99%) Melting point 28-30 ° C Boiling point 98-100 ° C (1.7mmHg) δ (CDCl ₃ ) 1.40 (3H, t, J = 7.3Hz) 4.34 (2H, q, J = 7.3Hz) 7.00 (1H , M) 7.22 (2H, m) FD-MS M ⁺ 218

Claims (2)

[Claims] 1. Formula 1 Carbonate derivative shown by. 2. A compound of the formula ## STR2 ## characterized in that 2-chloro-4-fluorophenol is reacted with ethyl chlorocarbonate. A method for producing a carbonic acid ester derivative represented by.