JPH0133096B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a fluorine-containing dicarboxylic acid and its derivatives, and more particularly to a method for producing a dicarboxylic acid having a perfluoroalkyl group and its esters and salts, as well as diols derived therefrom.

The fluorine-containing dicarboxylic acid is produced by reacting a malonic acid diester with an alkyl having a perfluoroalkyl group and a substitutable group (e.g., halogen) (see, for example, U.S. Pat. Nos. 3,578,701 and 3,639,438). ).

As a result of repeated research to develop a simpler method for producing fluorine-containing dicarboxylic acids and their derivatives, the present inventors have discovered that fluorine-containing dicarboxylic acids and their derivatives can be produced by reacting perfluoroalkyl iodide with fluorine-containing unsaturated dicarboxylic acid esters. A basic dicarboxylic acid ester is obtained,
It was discovered that fluorine-containing dicarboxylic acid can be produced by hydrolyzing it, and the present invention was completed.

That is, the gist of the present invention is as follows: Formula: RfI [] [In the formula, Rf represents a perfluoroalkyl group having 2 to 21 carbon atoms. ] A compound represented by the formula: [In the formula, R ₁ and R ₂ each represent an alkyl group having 1 to 5 carbon atoms, and m represents 0, 1 or 2. ] by reacting the compound represented by the formula: [In the formula, R ₁ , R ₂ , Rf and m have the same meanings as above. ]
The present invention relates to a method for producing a fluorine-containing dicarboxylic acid derivative, which is characterized in that a compound represented by the following formula is obtained. This compound [ ] can be obtained by subjecting its ester moiety to appropriate chemical transformations such as hydrolysis, transesterification, metal salt or ammonium saltation, etc. Formula: [In the formula, Rf and m have the same meanings as above. M ₁ and
M ₂ each represents an alkali metal, ammonium, hydrogen or an alkyl group having 1 to 5 carbon atoms. ]
It can be converted to the compound shown below. Furthermore, compound [ ] is reduced to form the formula: [In the formula, Rf and m have the same meanings as above. ] A fluorine-containing diol represented by can be obtained. The reaction between compound [] and compound [] may be performed by reacting them themselves, or may be carried out in the presence of a solvent. As a solvent, methyl ethyl ketone,
Preferred examples include butyl acetate, tetrahydrofuran, diethyl ether, and the like.

The reaction proceeds in the presence of a radical initiator, such as an azo initiator such as azobisisobutyronitrile or azobisvaleronitrile, or a peroxide such as benzoyl peroxide or t-butylperoxyisobutyrate. It will be done.

The reaction temperature is preferably 10 to 150°C, particularly 30 to 1000°C.

There are no particular restrictions on the reaction pressure, and normal pressure is usually employed.

Hydrolysis, transesterification, metal salting, etc. of the compound [] may be carried out according to conventional methods, and free carboxylic acids, various esters and salts can be obtained.

Reduction of compound [] or [] will yield the corresponding diol.

As the reducing agent, for example, lithium aluminum hydride, sodium borohydride, lithium borohydride, hydrogen and platinum oxide, hydrogen and palladium, sodium and alcohol, etc. are preferably used.

The reaction is usually carried out in a solvent such as diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, N-methylmorpholine, methanol, etc.
It is carried out at a temperature of ~100°C, preferably at the reflux temperature of the solvent.

The reaction pressure is usually normal pressure, but when hydrogen is used as the reducing agent, a pressure of from normal pressure to 150 atmospheres is used.

The amount of the reducing agent to be used is the stoichiometric amount or 10 times the stoichiometric amount. For example, when lithium aluminum hydride is used, at least 1 mol should be added per 1 mol of the raw material compound.

When the diol [ ] obtained in this way is oxidized, an iodine-free carboxylic acid is obtained. Oxidation may be carried out by a conventional method using potassium dichromate or potassium permanganate.

The fluorine-containing dicarboxylic acid and fluorine-containing diol obtained by the present invention can be made into polyurethane by reacting with an isocyanate having at least two isocyanate groups in one molecule. Moreover, any of them can be used as a monomer for producing polyester. Furthermore, these fluorine-containing dicarboxylic acids and diols can be added as modifiers to ordinary polyurethane, polyester, nylon, etc., and used to impart water and oil repellency.

Next, the present invention will be specifically explained by showing examples and application examples.

Example 1 0.1 ml of allylmalonic acid diethyl ester, 0.13 ml of (CF ₃ ) ₂ CFI and 5 g of azobisisobutyronitrile were placed in a four-necked flask equipped with a stirrer, thermometer, reflux condenser and dropping funnel. After charging and replacing the air in the flask with nitrogen, stir
The temperature was raised to 70°C, and the reaction was carried out at the same temperature for 3 hours. The excess (CF ₃ ) ₂ CFI was then heated at 100 °C under reduced pressure.
was removed. 41 g of pale yellow liquid (CF ₃ ) ₂ CFCH ₂ CHICH ₂ CH ₂ (COOC ₂ H ₅ ) ₂ was obtained as a residue.

Application example 1 7.5 g of lithium aluminum hydride was placed in two flasks equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel. After purging the inner space of the flask with nitrogen, 500 ml of diethyl ether was added from the dropping funnel. . Then, the ester obtained in Example 1
A solution of 200 ml of 0.1 ml diethyl ether was added from the dropping funnel over 2 hours, and the mixture was heated under reflux for an additional 15 minutes. After cooling, add 150 ml of dilute hydrochloric acid, separate the organic phase from the aqueous phase, and distill from the organic phase to obtain (CF ₃ ) ₂ CF.
21 g of (CF ₂ ) ₃ CH(CH ₂ OH) ₂ was obtained. Boiling point 144℃/
20mmHg. NMR, δ (ppm) = 2.5 (broad), 1.65 ~
1.80 (broad), 3.77 (doublet), 4.15 (broad).

Example 2 (CF ₃ ) ₂ A pale yellow viscous liquid was prepared in the same manner as in Example 1 except that C ₆ F ₁₇ I was used instead of CFI.
_{C6F13CH2CHICH2CH ( COOC2H5} ) _{2 was obtained .}

Application Example 2 The same procedure as in Application Example 1 was repeated except that the ester obtained in Example 2 was used to obtain C ₆ F ₁₃ (CH ₂ ) ₃ CH (CH ₂ OH) ₂ . Boiling point 163℃/
20mmHg. Melting point: 41℃.

Example 3 (CF ₃ ) ₂ A pale yellow viscous liquid was prepared in the same manner as in Example 1 except that C ₈ F ₁₇ I was used instead of CFI.
_{C8F17CH2CHICH2CH ( COOC2H5} ) _{2 was obtained .}

Application Example 3 The same procedure as in Application Example 1 was repeated except that the ester obtained in Example 3 was used to obtain C ₈ F ₁₇ (CH ₂ ) ₃ CH(CH ₂ OH) ₂ . Boiling point 190℃/
20mmHg. Melting point: 81℃. NMR, δ (ppm) = 2.5
(broad), 1.65-1.80 (broad), 3.77 (doublet),
4.15 (broad).

Application example 4 C ₈ F ₁₇ in 1 mol of tolylene diisocyanate
0.1 mol of (CH ₂ ) ₃ CH(CH ₂ OH) ₂ was added, and the mixture was reacted with stirring at room temperature until the mixture became homogeneous. Next, 0.9 mol of hexanediol was added, stirred and mixed, and then casted on a glass plate and reacted at room temperature for 24 hours. The reaction product was a tough film. The contact angles of water and n-hexane on this film were measured and found to be 126° and 72°, respectively.

Claims (1)

[Claims] 1. A compound represented by the formula: RfI and the formula: By reacting the compound shown by the formula: A method for producing a fluorine-containing dicarboxylic _acid derivative _, which is characterized by obtaining a compound represented by The group m represents 0, 1 or 2. ].