JPH06256250A - Production of monocarboxylic acid - Google Patents

Abstract

PURPOSE:To obtain in high yield at low cost a monocarboxylic acid useful as e.g. an interinediate for organic synthesis, raw material for medicines or pesticides, by heating a halocompound in the presence of water using an acid- type zeolite catalyst. CONSTITUTION:A compound of formula I or II (R<1> and R<2> are each H, halogen, 1-6C alkyl, 6-10C aryl, 5-12C alicyclic hydrocarbon, etc.; X is halogen) is heated at 150-350 deg.C in the presence of water using an acid-type zeolite catalyst to obtain the monocarboxylic acid of formula III. It is preferable that the molar ratio water the compound is 0.01-100 and the contact time for the catalyst and the compound 0.1-1000sec. With no use of conc. sulfuric acid, no problem such as corrosion occurs; besides, because of no formation of by-products such as sulfonated products, the aimed compound can be obtained without the need for troublesome purification processes and waste liquor treatment. The compound of the formula I is e.g. 1,1,1-trichloroethane, while the compound of the formula II is e.g. vinylidene chloride.

Description

Detailed Description of the Invention

[0002]

FIELD OF THE INVENTION The present invention relates to a method for producing a monocarboxylic acid. Monocarboxylic acid is widely used as a raw material for medicines, agricultural chemicals, organic synthetic intermediates, etc.
It is a useful compound.

[0003]

_2. Description of the Related Art Conventionally,> C = CX ₂ group or --CX ₃ group.
As a method for producing a corresponding monocarboxylic acid by hydrolyzing a compound having a group (X is a halogen atom),
A hydrolysis method using concentrated sulfuric acid is known (PB Report No. 63606). However, in this method, a large amount of highly corrosive concentrated sulfuric acid must be used, and carbides and sulfonates are by-produced, and separation and purification processes from by-products are required, and a large amount is required for waste liquid treatment. However, there are various industrial problems such as not only the above-mentioned alkali but also a complicated waste liquid treatment process.

[0004]

2. Description of the Related Art A method for producing monochloroacetic acid by hydrolyzing trichloroethylene with water using tungstosilicic acid as a catalyst has been disclosed (U
SSRSU 194802), this method is industrially disadvantageous in that a sufficient reaction rate cannot be obtained and a huge volume of reactor is required.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have found that> C =
In a method for producing a corresponding monocarboxylic acid by hydrolyzing a compound having a CX ₂ group or a -CX ₃ group, concentrated sulfuric acid is not used, and therefore there is no problem such as corrosion, and by-products such as sulfonates. Therefore, the present invention has been completed as a result of earnest research on a method for producing a monocarboxylic acid which is industrially advantageous with a sufficient reaction rate without requiring a complicated purification step and waste liquid treatment. It was

[0006]

Means for Solving the Problems The present invention uses an acid-type zeolite as a catalyst, and in the presence of water, a compound represented by the formula (1) or (2) (hereinafter, referred to as raw material compound) A method for producing a monocarboxylic acid represented by the formula (3), which comprises heating.

[0007]

[Chemical 4]

[0008]

[Chemical 5]

[0009]

[Chemical 6]

R ¹ or R ² in the compounds represented by the formulas (1), (2) and (3) is as described above, and preferably an atom such as hydrogen, fluorine, chlorine, bromine or iodine, or carbon. Examples thereof include halogenated or non-halogenated alkyl groups and phenyl groups of the formulas 1 to 2, and particularly preferably hydrogen, chlorine, fluorine and the like. In addition, R ¹ or R ² in the above formulas is not a trihalomethyl group or a group having the same.

X in the compounds of the formulas (1) and (2) is preferably chlorine and bromine, particularly preferably chlorine.

Preferred specific examples of the compound represented by the formula (1) include 1,1,1-trichloroethane, 1,1,
1-tribromoethane, 1,1,1,2-tetrachloroethane, 1,1,1-trichloro-2-fluoroethane, 1,1,1-trichloro-2-bromoethane, pentachloroethane, 1,1,1 , 2-tetrachloro-2-
C2 halogenated saturated hydrocarbons such as fluoroethane, 1,1,1-trichloropropane, 1,1,1-tribromopropane, 1,1,1,2-tetrachloropropane, 1,1,1- Trichloro-3-fluoropropane, 1,1,1,3-tetrachloropropane, 1,1,
1-trichloroisopropane, 1,1,1-trichloro-2-phenylethane, 1,1,1-trichloro-2-
Examples thereof include cyclohexylethane, and particularly preferably, a halogenated saturated hydrocarbon having 2 carbon atoms.

Preferred specific examples of the compound represented by the formula (2) include vinylidene chloride, vinylidene bromide, trichloroethylene, tribromoethylene, 1,1-dichloro-2-fluoroethylene and 1,1-dichloro-2-. C2-halogenated unsaturated hydrocarbons such as bromoethylene, tetrachloroethylene, 1,1,2-trichloro-2-fluoroethylene, 1,1-dichloropropene, 1,1
-Dibromopropene, 1,1,2-trichloropropene, 1,1,2-trifluoropropene, 1,1,3-
Trichloropropene, 1,1-dichloroisopropene,
1,1-dichloro-2-phenylethylene, 1,1-dichloro-2-cyclohexylethylene and the like can be mentioned, with particular preference given to halogenated unsaturated hydrocarbons having 2 carbon atoms.

The compound represented by the above formula (1) or formula (2), which is a starting material, may be used alone or in a mixture of both. In the present invention, when the compound represented by the formula (1) is used as a starting material, the corresponding monocarboxylic acid, the corresponding unsaturated compound represented by the formula (2), and a by-product hydrogen halide are produced. However, the compound represented by the formula (2) which is the corresponding unsaturated compound can be used as a raw material of the monocarboxylic acid of the present invention. Further, when the compound represented by the formula (2) is used as a starting material, the corresponding monocarboxylic acid and a by-product hydrogen halide are produced.

In the present invention, preferred examples of the desired monocarboxylic acid represented by the formula (3) include acetic acid, monochloroacetic acid, monofluoroacetic acid, monobromoacetic acid, dichloroacetic acid, difluoroacetic acid and chlorofluoroacetic acid. Acetic acid or its halides, propionic acid, 2
-Chloropropionic acid, 2-fluoropropionic acid, 3
-Chloropropionic acid, isobutyric acid, phenylacetic acid, etc. are mentioned, and acetic acid or its halide is particularly preferable.

The acid-type zeolite used as a catalyst in the present invention has hydrogen ions in the zeolite. As preferable acid type zeolite, for example, mordenite type, pentasil type such as ZSM-5 or ZSM-11, ferrierite type, faujasite type, L
Type, β type, offretite-erionite type zeolite and the like, more preferably, mordenite type, ZSM
Acid-type zeolites having SiO ₂ / Al ₂ O ₃ = 10 or more such as pentasil-type and ferrierite-type zeolites such as -5 or ZSM-11 are particularly preferable, and mordenite-type acid-type zeolites are particularly preferable.

The shape of the acid-type zeolite is not particularly limited and can be arbitrarily selected depending on the reaction type, and may be powder, granules as a molded body, spherical, tubular, tubular or the like. And if necessary, at the time of molding,
Binders such as silica sol, alumina sol and clay may be added. It can also be used as a mixture with an inert filler such as glass beads.

When the raw material compound is heated in the presence of water, the feed ratio of the raw material compound and water is preferably water / raw material compound (molar ratio) of 0.01 to 100, and more preferably 0.1 to 100. It is 10. If this value is less than 0.01,
There is a possibility that the conversion rate of the raw material compound may decrease, and if it exceeds 100, it is not economically advantageous.

The reaction in the present invention proceeds by heating. The reaction temperature varies depending on the type of raw material compound, the type of catalyst, and other reaction conditions, but is 150 ° C to 350 ° C.
Is preferable, and more preferably 200 ° C to 300 ° C.
Is. If it is lower than 150 ° C, it cannot be said that a sufficient conversion rate of the raw material compound can be obtained, and if it exceeds 350 ° C, the selectivity of the target monocarboxylic acids is lowered, and byproducts such as carbon monoxide and carbon dioxide are generated. May increase.

The above reaction may be carried out in the presence of an inert gas such as nitrogen and a diluting gas such as carbon dioxide and hydrogen chloride.
The diluent gas is preferably 0 to 20 times the mol of the raw material compound, and if it is too much, it is not economical.

Contact time between raw material compound and catalyst [W / F
(Sec)] is preferably 0.1 to 1000 sec,
More preferably, it is 0.5 to 500 sec. 0.1s
If it is less than ec, it cannot be said that a sufficient conversion rate of the raw material compound is obtained, and if it exceeds 1000 sec, the effect commensurate with the increase in the amount of the catalyst may not be expected. However, W (cc): Volume of catalyst layer F (cc / sec): When using raw material compounds and diluent gas, total supply amount of gas including this

This reaction can be carried out by any of reaction methods such as a continuous method and a batch method, and is usually carried out by a gas phase reaction, but a liquid phase reaction or a state where a gas phase and a liquid phase coexist. You may go in. Further, any of a fixed bed, a fluidized bed and a moving bed may be used, but the fixed bed is industrially preferable.

In the present invention, the conversion rate and the selectivity are values defined by the following formulas (amount represents mole). Conversion rate (%) = 100− (amount of unreacted raw material compound / amount of feed raw material compound) × 100 Selectivity (%) = {amount of monocarboxylic acid produced / (amount of feed raw material compound−amount of unreacted raw material compound)} × 100

The reaction pressure is 0.1 to 30 from the viewpoint of safety.
kg / cm ² (absolute pressure) is preferable, and 1 is more preferable.
10 kg / cm ² (absolute pressure).

The monocarboxylic acid obtained in this reaction can be easily separated and recovered by any of various methods such as liquid-liquid separation, solvent extraction, distillation and adsorption separation, or a combination thereof. , The unreacted raw material components are
By-products, such as hydrogen halide, carbon monoxide, carbon dioxide, etc., can be easily purified and recycled by partial condensation if necessary.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 A reaction tube (manufactured by Pyrex; 30 mmφ × 500 m) was used by using an ordinary fixed bed flow reactor.
(mL) acid type mordenite type zeolite HSZ-
650HOA (trade name, manufactured by Tosoh Co., Ltd., which is obtained by compressing and molding powder and then forming 10 to 14 mesh) 50 cc
At a reaction temperature of 200 ° C., trichloroethylene: water: nitrogen = 1: 2: 0.5 (molar ratio), and W / F
(Contact time) It was supplied for 21 seconds and the reaction was carried out for 4 hours.

After the reaction, the reaction products and the unreacted raw materials that flowed out were analyzed by gas chromatography, and as a result, the conversion rate of trichloroethylene was 18.6% and the selectivity of mochloroacetic acid was 99.9%. . In addition, hydrogen chloride was confirmed as a by-product. The conversion rate and selectivity of trichlorethylene were calculated based on the following formula (the amount represents mol). Conversion rate (%) = 100- (unreacted trichloroethylene amount / supplied trichloroethylene amount) × 100 Selectivity (%) = {monochloroacetic acid production amount / (supplied trichloroethylene amount-unreacted trichloroethylene amount)} × 1
00

(Example 2) The reaction was carried out for 4 hours under the same reaction apparatus and reaction conditions as in Example 1 except that the reaction temperature was 250 ° C. As a result, the conversion of trichlorethylene was 82.9% and the selectivity of monochloroacetic acid was 95.7.
%Met. Hydrogen chloride, carbon monoxide and carbon dioxide were confirmed as by-products.

Example 3 A reaction was carried out for 4 hours under the same reaction apparatus and reaction conditions as in Example 1 except that 1,1,1,2-tetrachloroethane was used instead of trichloroethylene. As a result, the conversion of 1,1,1,2-tetrachloroethane was 27.9% and the selectivity of monochloroacetic acid was 99.9%. The leaked 1,1,
The molar composition ratio of the mixture of 1,2-tetrachloroethane and trichloroethylene was 1,1,1,2-tetrachloroethane: trichloroethylene = 4: 96.

The conversion rate and selectivity of 1,1,1,2-tetrachloroethane were calculated by the following formulas (amount represents mole). Conversion rate (%) = 100-{(amount of unreacted tetrachloroethane + amount of trichloroethylene in reaction product mixture) / amount of supplied tetrachloroethane} × 100 Selectivity (%) = [amount of produced monochloroacetic acid / {amount of supplied tetrachloroethane- (Amount of unreacted tetrachloroethane + amount of trichlorethylene in the reaction product mixture)}] × 100

[0032]

According to the present invention, a --CX ₃ group or> C
In the method for producing a corresponding monocarboxylic acid from a compound having a ═CX ₂ group, there is no problem such as corrosion and separation,
The purification process is easy, there is no problem in waste liquid treatment, and the monocarboxylic acid can be produced at high yield and at low cost.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number in the agency FI technical display location // C07B 61/00 300 (72) Inventor Teruo Yoshida 1 Funami-cho, Minato-ku, Nagoya-shi, Aichi 1 Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute

Claims (1)

[Claims] 1. A monocarboxylic acid represented by the formula (3), which comprises heating the compound represented by the formula (1) or (2) in the presence of water using an acid-type zeolite as a catalyst. Manufacturing method. [Chemical 1] [Chemical 2] [Chemical 3] [0001]