JPS6078943A - Production of alpha-fluoroacrylic acid ester - Google Patents

Abstract

PURPOSE:To produce the titled substance useful as a raw material of a polymer having excellent weather resistance, etc., resistant to cracking, and useful as a raw material of paint, etc., by reacting alpha-fluoro-beta-halogenopropionic acid ester with a basic substance. CONSTITUTION:The objective compound is produced by reacting an alpha-fluoro-beta- halogenopropionic acid ester with a basic substance, e.g. an alkali metal or alkaline earth metal hydroxide, ammonia, a primary - tertiary amine, etc., if necessary in a solvent such as benzene, dioxane, etc. usually at 20-100 deg.C. The above ester used as a raw material can be synthesized e.g. by (1) reacting trifluoroethylene with formaldehyde and chlorosulfonic acid, (2) reacting the product successively with potassium halide (halogen is Cl, Br or I) and water, and (3) subjecting the resultant alpha-fluoro-beta-halogenopropionic acid to the dehydrative condensation with an alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing α-fluoroacrylic acid ester.

α-Fluoroacrylic acid ester can be polymerized by a normal polymerization method, and its η polymer has a higher thermal softening temperature and thermal decomposition temperature than methacrylic acid entel polymer, and has excellent weather resistance. It has the advantage of not being prone to cracking, making it suitable for use as insoles, paint raw materials, optical fiber sheath materials, semiconductor resist materials, etc.

The purpose of the present invention is to provide a new method for producing α-fluoroacrylic acid ester, and to produce α-fluoroacrylic acid ester using I! ! In building.

It is characterized by reacting α-fluoro-β-halogenopropionic acid ester with a basic substance.

Bromine or iodine.

In the present invention, the basic substance refers to a substance that has the function of eliminating hydrogen at the α position and halogen at the β position of the α-fluoro-β-halogenopropionic acid ester, which is the raw material for the production method of the present invention. Examples of these include hydroxides of alkali metals and alkaline earth metals, ammonia, and primary to tertiary amines. Among these, the alkali metal hydroxide is usually used by preliminarily dissolving 50% by weight or less in water or a lower alcohol such as methanol.

The a-fluoro-β-halogenofropionic acid ester, which is the raw material of the present invention, is obtained by reacting one, for example, trifluoroethylene, formaldehyde, and chlorsulfuric acid, and has the formula: Cl5O30CI(!CF)ICF, 0803
A compound represented by C71 was obtained. This compound was then reacted with /) potassium halogenide (where hepgen is chlorine, bromine or iodine) and water in order to obtain α-fluoro-β-
It is synthesized by converting it into octahegenopropionic acid, and dehydrating and condensing this α'-fluoroβ-octahegenopropionic acid with alcohol in a conventional manner.

can do. Any alcohol can be used as long as the remainder of the alcohol excluding the 10H group does not react with the basic substance referred to in the present invention, including lower alcohols such as methanol, ethanol, propatool, and their halogens. compounds are preferably used.

Although a solvent may or may not be used when carrying out the present invention, examples of solvents that can be used include aromatic hydrocarbons such as benzene and toluene, ethers such as dioxane and tetrahydrofuran, methyl isobutyl ketone, etc. Examples include ketones, esters such as ethyl acetate, and halogenated hydrocarbons such as chloroform.

The reaction temperature when carrying out the present invention is usually 20 to 100°C.
It is. If the reaction temperature is lower than the above, the reaction rate will be low;
When the temperature is high, the α-fluoroacrylic acid ester formed is likely to undergo mold combination during the reaction.

Next, examples of the present invention will be shown.

Example 1 Methanol solution 16 containing 5% by weight of potassium hydroxide in methyl α-fluoro-β-iodopropionate 30f
01/ was added dropwise while stirring. After reacting for 5 hours at a reaction temperature of 40°C, the resulting reaction mixture was purified to obtain methyl α-fluoroacrylate (boiling point: 45°C/180 lIn).
Hg) 5.41 was obtained.

Example 2 "Instead of the methanol solution of potassium hydroxide in Example 1,
The reaction was carried out in the same manner as in Example 1 except that triethylamine tp was used, and 8.8 g of methyl α-fluoroacrylate was used.
I got it.

that's all

Claims (1)

[Scope of Claims] 1. A method for producing a-fluoroacrylic acid ester, which comprises reacting α-fluoro-β-octahegutupropionic acid ester and a basic substance. 2. The four methods for preparing α-fluoroacrylic acid esters according to claim 1, wherein the basic substance is an alkali metal hydroxide, an alkali metal hydroxide, ammonia or an amine.