JPS5929572B2 - New manufacturing method for carboxylic acid derivatives - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves synthesizing carboxylic acid fluoride using hexafluoro-1,2-epoxypropane (also referred to as hexafluoropropylene oxide, hereinafter abbreviated as HFPO), and then adding alcohol to this reaction product. , relates to a novel method for producing carboxylic acid derivatives, which consists of reacting a nucleophile such as an amine.

Conventionally known methods for synthesizing carboxylic acid fluorides include a method in which the corresponding carboxylic acid chloride is substituted with fluorine (A, G, Pyttman et al., J.

Org, Chem, Vol. 3l, p. 2316), but it cannot be synthesized in one step from a carboxylic acid. HFPO has recently been used as a monomer for ion exchange resins, and its reactivity has also attracted attention.

The present inventor has discovered that when HFPO is reacted with carboxylic acids in the presence of a tertiary amine, carboxylic acid fluoride can be obtained in high yield under extremely mild conditions, and that nucleophilic reagents such as alcohols and amines can be added to the reaction mixture. They discovered that carboxylic acid derivatives such as esters and amides can be easily produced by adding . The method of the present invention includes:
After reacting carboxylic acid and HFPO in the presence of a tertiary amine, the general formula RX...
...(I) (wherein R represents a residue of an aliphatic compound, alicyclic compound or aromatic compound, and X represents a hydroxyl group or a mercapto group) or the general formula R'・・・・・・・・・・・・・・・・・・・・・
'') (wherein R' represents hydrogen or a residue of an aliphatic compound, alicyclic compound, or aromatic compound, and R'' represents a residue of an aliphatic compound, an alicyclic compound, or an aromatic compound) This is a novel method for producing carboxylic acid derivatives, which is characterized by reacting a compound represented by

HFPO used in the present invention is produced by oxidizing hexafluoropropylene (HFP, CF3CF=CF2) with hydrogen peroxide or the like in aqueous alcohol-potassium hydroxide.

Since HFPO is a gas (boiling point -27.4°C) at room temperature, the usual method for adding gas or liquid HFPO to the reaction system is adopted. H
The addition ratio of FPO is approximately 1 equivalent relative to the carboxylic acid as a raw material.

The starting carboxylic acid used in the method of the present invention may be an aliphatic or aromatic carboxylic acid or an alicyclic carboxylic acid.

The aliphatic carboxylic acid may be an unsubstituted or substituted carboxylic acid. Examples include acetic acid, propionic acid, butyric acid, and carboxylic acids whose hydrogen groups are substituted with alkyl groups, aryl groups, nitro groups, substituted amino groups, or alkoxyl groups. Divalent or polyvalent carboxylic acids such as tedipic acid are also selected. Aromatic carboxylic acids include benzoic acid, naphthoic acid,
Unsubstituted monocarboxylic acids such as anthracenecarboxylic acid or substituted monocarboxylic acids with substituents such as alkyl groups, aryl groups, nito-substituted amino groups or alkoxyl groups such as toluic acid, diphenylcarboxylic acid, nitrobenzoic acid or methoxy Examples include benzoic acid.

In addition, if necessary, polyvalent carboxylic acids such as phthalic acid and trimesic acid may also be selected. The tertiary amine used in the process of the invention is usually selected from trialkylamines or mixed tertiary amines of alkyl and aryl groups.

Specifically, the trialkylamines include trimethylamine, triethylamine, tripropylamine,
Mixed alkyl tertiary amine or N・N-N'・N7-
Tetramethylethylenediamine [(CH3)2-N-C
H2-CH2-N(CH3)2], and hybrid tertiary amines of alkyl and aryl groups, such as N-
Examples include N-dimethylaniline and N-N-diethylaniline. The amount of tertiary amine added is preferably at least the equivalent of HFPO. Examples of the compound represented by formula (1) above include alcohols, phenols, thiols, and thiophenols.

More specifically, the alcohols include aliphatic alcohols such as methanol, ethanol, propanol, and octanol, alicyclic alcohols such as cyclohexanol, or these alcohols and alkyl groups;
Substituted alcohols substituted with aryl groups, nitro groups, etc.; Examples of phenols include unsubstituted phenols such as phenol and naphthol, and phenols with substituents such as alkyl groups, aryl groups, and nitro groups, such as cresol, xylenol, and nitro groups. Phenol, hydroxybiphenyl; Thiols include aliphatic thiols (so-called alkylmercaptans) such as methylthiol, ethylthiol, and propylthiol, or substituted thiols substituted with alkyl groups, aryl groups, nitro groups, etc.; thiophenols Examples include unsubstituted thiophenols such as thiophenol and thionaphthol, and thiophenols having substituents such as alkyl groups, aryl groups, and nitro groups, such as thiocresol, mercaptobiphenyl, and nitrothiophenol. The compound represented by (11) in the above general formula specifically represents primary or secondary amines.

For example, aliphatic primary amines such as ethylamine, propylamine, butylamine; aromatic primary amines such as aniline, naphthylamine; aliphatic secondary amines such as diethylamine, dipropylamine, ethyl-butylamine; methylaniline, Aromatic secondary amines such as ethylnaphthylamine; and other primary or secondary amines listed above, in which the hydrogens of the alkyl and aryl groups are replaced by other substituents, such as alkyl, aryl or nitro groups. Mention may be made of substituted primary or secondary amines. The compound represented by the above general formula (1) or () is used in an approximately equivalent amount to the starting carboxylic acid.

In the method of the present invention, acetonitrile (
Inert, aprotic polar solvents such as CH3CN), sulfolane, and dioxane are preferred. The reaction temperature is usually selected from room temperature to 80°C, but room temperature is generally sufficient. The reaction pressure may be normal pressure or elevated pressure.

To carry out the method of the present invention, the carboxylic acid and the tertiary amine are usually first dissolved in a solvent, and after cooling, a predetermined amount of HFPO is added, and then the contents are stirred at room temperature to 80°C.
Reconstitute and stir for about 10 to 90 minutes to react.

Next, a compound represented by the general formula (1) or () is added to the reaction mixture, and the mixture is reacted at room temperature to 80°C for several minutes to several hours. After the reaction is completed, the desired carboxylic acid derivative is separated by a commonly used post-treatment method. Post-treatment methods include, for example, diluting the reaction mixture containing the carboxylic acid derivative with water to precipitate the product, filtering and drying, and separating the precipitated product; Examples include a method of extraction with a suitable solvent or a method of distilling the reaction mixture under reduced pressure. If further purification is required, recrystallization or redistillation may be performed.

In this way, carboxylic acid derivatives such as carboxylic esters, carboxylic thioesters, or carboxylic amides can be obtained in high yields. As described above, according to the method of the present invention, carboxylic acid derivatives can be prepared under very mild conditions.
That is, it can be obtained in good yield at room temperature and around normal pressure. Furthermore, it is particularly effective when producing carboxylic acid fluorides, esters, thioesters, or amides using thermally unstable carboxylic acids and/or alcohols, thioalcohols, or amines. That is clear. Hereinafter, the present invention will be explained in detail with reference to Examples. Example 1 Propionic acid 1,48
7 (20mm01), triethylamine 3.037 (3
A mixture of 0mm01) and 20ml of acetonitrile as a solvent was placed in a pressure-resistant container and cooled to -75°C in a dry ice-acetone bath to cool and liquefy HFPO3. O57
(18.4 sig MmOl) was added.

Thereafter, the bath was removed and the mixture was allowed to stand for about 10 minutes until it reached room temperature, and then stirred at room temperature for 30 minutes to react. Then,
Aniline 1.867 (20 mm01) was added dropwise and stirred again at room temperature for 30 minutes to react. After the reaction is complete, the contents are reduced to 1
The precipitated solid was filtered and dried. Crude propionic acid anilide 1.407 (M.P3lO
57°C). On the other hand, the aqueous layer was extracted with ether, washed with water, dried over magnesium sulfate, and the ether was distilled off under reduced pressure.
03°C) 1,217 was obtained. When the two products are combined, the yield of crude propionic acid anilide is 95%.
When the crude propionic acid anilide was recrystallized from carbon tetrachloride, M. P. Pure propionic acid anilide with lO6-7°C was obtained (literature value M.P.lO5-6°C). The infrared spectrum of the purified product confirmed that it was propionic acid anilide. Example 2 Same as Example 1 except that propionic acid, isobutyric acid, or benzoic acid was used as the raw material carboxylic acid, phenol, aniline, or thiophenol was used as the nucleophile, and the reaction time after addition of the nucleophile was changed. The reaction was carried out in the same manner.

Claims (1)

[Claims] 1. In the presence of a tertiary amine, a carboxylic acid and hexafluoro-1,2-epoxypropane are reacted, and then a compound of the general formula RX (wherein R is an aliphatic compound, an alicyclic compound or an aromatic compound) is reacted with a carboxylic acid and hexafluoro-1,2-epoxypropane. X represents a hydroxyl group or a mercapto group) or a general formula ▲ Numerical formula, chemical formula, table, etc. (R″ represents a residue of an aliphatic compound, alicyclic compound, or aromatic compound)
1. A novel method for producing carboxylic acid derivatives, which comprises reacting with a compound represented by: