JP2018158950A - Method for producing 2-chloroacetoacetamide - Google Patents

Abstract

A method for producing 2-chloroacetoacetamide in high yield is provided. In an ethanol solvent, acetoacetamide and trichloroisocyanuric acid (provided that trichloroisocyanuric acid is 0.30 to 0.38 mol times with respect to acetoacetamide) are preferably reacted with ethanol. The method for producing 2-chloroacetoacetamide, characterized in that the amount is 3 to 10 times by weight with respect to acetoacetamide. [Selection figure] None

Description

  The present invention relates to a method for producing 2-chloroacetoacetamide.

  It is known that 2-haloacetoacetamide can be produced by reacting acetoacetamide with various halogenating agents (Patent Document 1). In this reaction, it is also known that 2-haloacetoacetamide further reacts with a halogenating agent to produce 2,2-dihaloacetamide.

JP 2017-19744 A

  This invention makes it a subject to provide the manufacturing method which can obtain 2-chloroacetoacetamide with a high yield from acetoacetamide as a raw material.

  As a result of intensive investigations on the halogenation reaction on acetoacetamide and the types of halogenating agents and solvents and other reaction conditions, 2-chloroacetoacetamide was obtained in a high yield in the production method described below. I found out that

That is, the present invention is as follows.
[1] It is characterized by reacting acetoacetamide with trichloroisocyanuric acid (provided that trichloroisocyanuric acid is 0.30 to 0.38 mol times with respect to acetoacetamide) in an ethanol solvent, Method for producing 2-chloroacetoacetamide [hereinafter referred to as this production method].
[2] The method for producing 2-chloroacetoacetamide according to [1], wherein the amount of ethanol is 3 to 10 times by weight with respect to acetoacetamide.

  According to the present invention, 2-chloroacetoacetamide can be produced in high yield.

  Hereinafter, this production method will be described in detail.

The acetoacetamide and trichloroisocyanuric acid used in the present invention are known products, and can be produced according to known production methods, or commercially available products can also be used.
A commercial item can be used for the solvent etc. which are used by this invention.

The ratio of acetoacetamide and trichloroisocyanuric acid is 1/3 mole of theoretical amount of trichloroisocyanuric acid with respect to 1 mole of acetoacetamide, but is usually 0 from the viewpoint of reaction conversion and impurity suppression. Used in a proportion of 30 to 0.38 mol.
Ethanol used as a solvent is usually used in a ratio of 3 to 10 times by weight with respect to acetoacetamide.

For the reaction, a method of adding trichloroisocyanuric acid to a mixture of acetoacetamide and ethanol is usually used. Can be adjusted. Since trichloroisocyanuric acid is solid at room temperature, it is carried out by adding granular parts or adding an ethanol solvent slurry.
The reaction temperature is usually in the range of -5 to 60 ° C, preferably in the range of 0 to 30 ° C. The temperature at which trichloroisocyanuric acid is added to the reaction system and the temperature at which aging is performed after all the trichloroisocyanuric acid has been added may be changed.
By sampling from the reaction system, the residual amount of acetoacetamide and the amount of 2-chloroacetoacetamide produced can be analyzed by gas chromatography or the like. Moreover, the reaction end point can be determined by confirming the disappearance of trichloroisocyanuric acid by the iodine-starch reaction. The aging time is usually 0.5 to 5 hours.
After completion of the reaction, the insoluble matter (mainly isocyanuric acid) in the reaction mixture is filtered off as necessary, and then the filtrate is concentrated or a nonpolar solvent is added to the filtrate to give crude 2-chloroacetoacetamide. Crystals can be obtained. The obtained crude crystals can be washed and dried, and further subjected to recrystallization or the like to obtain purified 2-chloroacetoacetamide.

  Next, in this production method, inorganic salts may be appropriately added in order to stabilize the stirring state of the reaction mass and the pH in the reaction system. Examples of inorganic salts include sodium hydrogen sulfate and ammonium chloride.

  Hereinafter, although an example etc. explain the present invention, the present invention is not limited only to these examples.

  In the following examples, unless otherwise specified, analysis of the reaction product was performed using gas chromatography (hereinafter referred to as GC). The analysis conditions are as follows.

[Gas chromatography (GC) measurement conditions]
・ Measuring equipment: GC-2010 manufactured by Shimadzu Corporation
Column: DB-1 30m long, 250μm inside diameter, 1.00μm thick (manufactured by Agilent Technologies)
-Column temperature: Increased from 80 ° C to 300 ° C at 10 ° C / min and then held at 300 ° C for 15 min. · Helium gas flow rate: 1.0 mL / min
・ Retention time (rt) Acetoacetamide (7.3 min), 2-chloroacetoacetamide (8.7 min), 2,2-dichloroacetoacetamide (10.6 min)

Example 1
To a mixture of 0.5 g (about 4.9 mmol) of acetoacetamide and 2.5 g of ethanol, 0.4 g of trichloroisocyanuric acid (0.34 mol times with respect to acetoacetamide) was added at 0 ° C. Stir for hours. After sampling from the reaction mass and diluting with acetonitrile, the production ratio was analyzed by GC. The results are shown in Table 1.

[Table 1]

(Example 2)
To a mixture of 0.5 g of acetoacetamide (about 4.9 mmol) and 2.5 g of ethanol, 0.4 g of trichloroisocyanuric acid (0.34 mol times with respect to acetoacetamide) was added at 30 ° C. Stir for hours. After sampling from the reaction mass and diluting with acetonitrile, the production ratio was analyzed by GC. They were 79% 2-chloroacetoacetamide, 10% acetoacetamide, and 11% 2,2-dichloroacetoacetamide.

(Example 3)
To a mixture of 0.5 g (about 4.8 mmol) of acetoacetamide, 0.09 g of ammonium chloride and 2.5 g of ethanol, 0.4 g of trichloroisocyanuric acid (0.34 mol times with respect to acetoacetamide) was added at 0 ° C. The mixture was stirred at the same temperature for 1.5 hours. After sampling from the reaction mass and diluting with acetonitrile, the production ratio was analyzed by GC. 2-chloroacetoacetamide 85%, acetoacetamide 7%, 2,2-dichloroacetoacetamide 8%.

Example 4
To a mixture of 2.5 g of acetoacetamide and 24.3 g of ethanol, 1.9 g of trichloroisocyanuric acid was added at 0 ° C. and stirred at the same temperature for 1 hour. The GC analysis was performed after sampling from the reaction mass and diluting with acetonitrile. 2-chloroacetoacetamide 81%, acetoacetamide 9%, and 2,2-dichloroacetoacetamide 10%.

(Example 5)
To a mixture of 50.0 g of acetoacetamide and 243 g of ethanol, 38.3 g of trichloroisocyanuric acid was added in portions at 0 ° C. over 1 hour. When the GC analysis was performed after sampling from the reaction mass immediately after the divided addition and diluting with acetonitrile, 84.7% of 2-chloroacetoacetamide, 5.5% of acetoacetamide, and 2,2-dichloroacetoacetic acid The amide was 9.8%. Insoluble matters were removed from the reaction mixture by filtration to obtain a solution containing 55.3 g of 2-chloroacetamide.
By concentrating the obtained solution, 60.1 g (content 83.6 wt%) of crude crystals of 2-chloroacetoacetamide was obtained. The crude crystals were recrystallized using a mixed solvent of 37.7 g of ethanol and 12.5 g of heptane to obtain 40.1 g (content 100.0 wt%) of 2-chloroacetoacetamide crystals.

  By the production method of the present invention, 2-chloroacetoacetamide can be produced in high yield.

Claims (2)

  2-chloroacetate, characterized by reacting acetoacetamide with trichloroisocyanuric acid (however, trichloroisocyanuric acid is 0.30 to 0.38 mole times with respect to acetoacetamide) in an ethanol solvent. A method for producing acetic acid amide.   The method for producing 2-chloroacetoacetamide according to claim 1, wherein the amount of ethanol is 3 to 10 times by weight with respect to acetoacetamide.