JPH1087554A - Process for producing amidocarboxylic acid or alkoxycarboxylic acid and salts thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compound, hardly causing irritation to skin, excellent in foaming properties and useful for detergents, etc., by oxidizing an alcohol having amide group, etc., with a chlorine-based oxidizing agent in the presence of nitroxide radicals and an alkali(ne earth) metal halide. SOLUTION: An alcohol having amide group and/or an alkoxy group or an alkenyloxy group is oxidized with a chlorine-based oxidizing agent such as sodium hypochlorite or chlorine in the presence of nitroxide radicals (preferably 2,2,6,6-tetramethyl-piperidine-1-oxyl, etc.) and an alkali(ne earth) metal halide to afford an amido- and/or an alkoxy- or an alkenyloxy-carboxylic acid (salt) useful as a surfactant for shampoos, body shampoos, detergents for tablewear and vegetables, detergents for fashionable wears, soaps, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to amides and / or amides.
Also, the present invention relates to a novel method for producing an alkoxy- or alkenyl-oxycarboxylic acid or a salt thereof.

[0002]

2. Description of the Related Art Among the surfactants, anionic surfactants are widely used as components of detergents generally used in the industrial field and at home. This anionic surfactant has various structures, but recently, an anionic surfactant having good water solubility, good detergency and good foaming, and mild on the skin and hair has been desired. Among the studies corresponding to these, there are amide ether carboxylic acids, alkoxy ether carboxylic acids, alkenyl ether carboxylic acids and the like as such anionic surfactants.

[0003] There are various methods for producing a corresponding carboxylic acid by oxidizing an alcohol, for example, an alcohol having an amide group, an alkoxy group, or an alkenyloxy group or an alcohol having an ether group, as shown below. Are known. JP-A-62-198649 (Kao) Polyoxyethylene fatty acid amide and polyoxyethylene alkylamine are converted to platinum and / or palladium or a catalyst comprising selenium, tellurium, antimony, tin, bismuth and lead. Discloses a method for producing a carboxylic acid by catalytic oxidation with an oxygen-containing gas. However, this method has problems that a high temperature is required and expensive noble metals must be used. J Org. Chem. 52,2559 (1987) 4-methoxy-2,2,6,6-tetramethylpiperidine-1-
Using oxyl or its oxoammonium salt,
A method is disclosed for oxidizing a primary alcohol to an aldehyde or carboxylic acid in a water / methylene chloride system in the presence of a phase transfer catalyst. However, this method has a problem that an expensive phase transfer catalyst must be used.

Further, as a method for performing an oxidation reaction in the presence of a nitroxide radical, the following method is known. JP-A-5-194334 (Sandz AG) Hydroxy group-containing compounds selected from polyoxyalkylene siloxanes, polyoxyalkylene amines, alkyl polyoxyalkylenes, polyoxyalkylene block copolymers, alkyl amide polyoxyalkylenes and alkyl polyglucosides are weakened. A process is disclosed for producing the corresponding carboxylate by reacting with at least an equimolar amount of an inorganic or organic halo-containing oxidizing agent in the presence of a base and a catalytic amount of a hindered nitroxide. However, this method does not provide a sufficient conversion to carboxylic acid. JP-A-4-28337 (Shell Int.) Oxidation of an alkoxyalkanol using an oxidizing agent such as sodium hypochlorite in the presence of 2,2,6,6-tetramethyl-piperidine-1-oxyl A method for producing an alkanoic acid is disclosed. However, this method has insufficient conversion and selectivity to carboxylic acid.

[0005]

The present invention provides an amide group,
An alkoxy group, an alkenyloxy group, or two of these
An object of the present invention is to provide a method for producing a desired carboxylic acid or salt having a high selectivity by oxidizing an alcohol having at least two or more groups or an alcohol having an ether group.

[0006]

According to the present invention, an alcohol having an amide group and / or an alkoxy group or an alkenyloxy group is converted into a chlorine-based oxidizing agent in the presence of a nitroxide radical and an alkali metal halide or an alkaline earth metal halide. The present invention provides a process for producing an amide- and / or alkoxy- or alkenyloxy-carboxylic acid or a salt thereof, characterized in that the method comprises oxidizing with an amide. That is, the present inventors have conducted intensive studies and found that when a chlorine-based oxidizing agent is used to oxidize an alcohol having an amide group, an alkoxy group, an alkenyloxy group or the like, or further having an ether group in the presence of a free radical nitroxide. It has been found that the addition of an alkali metal halide or an alkaline earth metal halide greatly improves the selectivity to a target carboxylic acid, and has completed the present invention.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The starting alcohol used in the production method of the present invention is, for example, a compound represented by the following general formula (1): R ¹ -X- (CH ₂ ) ₁ O (AO) _m (C ₂ H ₄₎ O) _n H (1) (wherein, R ^{1 is} a straight or branched chain having 8 to 22 carbon atoms;
Alkyl or alkenyl group X; -CON (R ²⁾ - or -N (R ²⁾ CO- or oxygen atom R ^2; H, an alkyl group or hydroxyalkyl group having 1 to 6 carbon atoms, or, - (AO) _{m (C 2 H 4 O)} n H a; C2-4, linear or branched alkylene group having l; 1 to 6 integer m, n; 0 to 20
), An amide group, an alkoxy group,
An alcohol having an alkenyloxy group or further having an ether group.

In the production method of the present invention, the starting alcohol is oxidized with a chlorine-based oxidizing agent in the presence of a stable nitroxide radical and an alkali (or alkaline earth) metal halide, whereby the following general formula (2) is obtained. The corresponding carboxylic acids represented or salts thereof can be prepared. [Formula 2] R ¹ -X- (CH ₂ ) ₁ O (AO) _m (C ₂ H ₄ O) _n-1 CH ₂ COOM (2) (wherein, R ^{1 is} a straight chain having 8 to 22 carbon atoms) Or branched,
Alkyl or alkenyl group X; -CON (R ³⁾ - or -N (R ³⁾ CO- or oxygen atom R ^3; H, alkyl group or carbon number of 1 to 6 carbon atoms 2
A carboxyalkyl group of 5, or-(AO) _m (C ₂ H ₄ O)
_n-1 CH ₂ COOM A; C2-4, linear or branched alkylene group having l; 1 to 6 integer m, n; 0~20 M; hydrogen atom, an alkali metal, alkaline earth metal, ammonium Or organic ammonium
)

However, when m ≠ O and n = O, a carboxylic acid represented by the following general formula (3) or a salt thereof can be produced.

Embedded image R ^1- ×-(CH ₂ ) _l O (AO) _m-1 -B-COOM (3) (wherein R ¹ , A, l and M are the same as described above) X; -CON ( R ⁴ ) — or —N (R ⁴ ) CO— or an oxygen atom R ⁴ ; H, an alkyl group having 1 to 6 carbon atoms or 2 to 2 carbon atoms
A carboxyalkyl group of 5, or-(AO) _m-1 -B-CO
OM B; group obtained by removing a methylene group bonded to a hydroxyl group from group A; m;
)

When m = 0 and n = 0, a carboxylic acid represented by the following general formula (4) or a salt thereof can be produced.

R ¹ -X- (CH ₂ ) _{1 -1} -COOM (4) (wherein R ¹ and M are the same as those described above for X; CONR ⁵ or —N (R ⁵ ) CO— or an oxygen atom R ⁵ ; an alkyl group having 1 to 6 carbon atoms or a carboxyalkyl group having 2 to 5 carbon atoms l; an integer of 2 to 6
)

The stable nitroxide radical (hindered nitroxide) used in the present invention is obtained by oxidizing a cyclic or non-cyclic secondary amine having no hydrogen in the substituent on the carbon adjacent to N with peroxide or the like. It is produced by oxidation of hydroxyamine. Such nitroxides are described in the following literature: Chem. Review, 78 , 37 (1978). G. Rozantsev, "Free Nitroxyl Radicals", Plenum Pub.
Stable nitroxy radicals described in Corp., New York, 1970. EGRozantsev, VDSholle, Synthesis, 1971 , 190. can be used. They include linear, cyclic, bicyclic or
A polymer having a plurality of nitroxy radicals connected is also included.

Preferred nitroxide radicals are shown below. 2,2,6,6-tetramethyl-piperidine-1-oxyl 2,2,5,5-tetramethyl-pyrrolidine-1-oxyl 1-aza-2,2,7,7-tetramethyl-cycloheptane-
1-Oxyl These derivatives can also be used, and preferred ones are shown below. 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl 4-methoxy-2,2,6,6-tetramethyl-piperidine-
1-oxyl 4-ethoxy-2,2,6,6-tetramethyl-piperidine-
1-oxyl 4-acetylamino-2,2,6,6-tetramethyl-piperidine-1-oxyl 4-carbamoyl-2,2,6,6-tetramethyl-piperidine-1-oxyl 4-benzoylamino-2 , 2,6,6-Tetramethyl-piperidine-1-oxyl 4-oxo-2,2,6,6-tetramethyl-piperidine-1
-Oxyl 2,2,6,6-tetramethyl-piperidine-1-oxyl-
4-sulfate 2,2,6,6-tetramethyl-piperidine-1-oxyl-
4-phosphate 3-carbamoyl-2,2,6,6-tetramethyl-pyrrolidine-1-oxyl Further, it is also possible to use an amine or hydroxylamine which is a precursor thereof, and oxidize this at the time of use. Alternatively, the stable free radical nitroxide may be oxidized with hypochlorite or the like and used as an oxoammonium salt.

The nitroxide radical is used in an amount of 0.001 to 0.5 molar equivalent per equivalent of the starting alcohol.
Preferably, it is 0.005 to 0.1 molar equivalent.

Specific examples of the chlorine-based oxidizing agent used in the present invention are shown below. Chlorine, hypochlorite, trichloroisocyanuric acid, dichloroisocyanuric acid, etc. Among these, preferred are sodium hypochlorite, calcium hypochlorite, and chlorine.

The use amount of the chlorine-based oxidizing agent is at least equimolar, preferably 1.5 to 3 molar equivalents, per equivalent of the starting alcohol.

Specific examples of the alkali metal halide and alkaline earth metal halide used in the present invention are shown below. Alkali metal bromide, alkali metal chloride, alkaline earth metal bromide, alkaline earth metal chloride. Sodium chloride, sodium bromide, potassium chloride, potassium bromide, calcium chloride, calcium bromide, magnesium chloride, magnesium bromide, etc.

The amount of the alkali metal halide or alkaline earth metal halide to be used is 0.01 to 0.5 molar equivalent, preferably 0.05 to 1 equivalent of the starting alcohol.
０．３0.3 molar equivalent.

In the method for producing a corresponding carboxylic acid by oxidizing a starting alcohol according to the present invention, the oxidation reaction is carried out at a pH of 10 or less, preferably at a pH of 9 or less, more preferably at a pH of 8.0 to 9.0. In order to carry out the oxidation reaction in such a pH range, the pH is adjusted to 8.0 to 9.0 at the stage when the chlorine-based oxidizing agent is added in an amount of 0.10 mol equivalent to 1 equivalent of the raw material alcohol. Thereafter, the reaction is carried out at pH 9.0 or lower.

In the present invention, in order to adjust the pH of the oxidation reaction in this way, a pH adjuster can be used, but the pH of the reaction system is 10 or less (preferably 8.0 to 9.0).
Anything that can be set to 0) may be used. As the pH adjuster, organic acids such as formic acid, acetic acid, and propionic acid, sulfuric acid, hydrochloric acid, and phosphoric acid can be preferably used.

The reaction temperature of the oxidation reaction is from -10 to
The temperature is 60 ° C., preferably 0 to 30 ° C., and aging is performed at 20 to 60 ° C. by adding a chlorine-based oxidizing agent.

In the present invention, the above-mentioned oxidation reaction is preferably carried out in the presence of a solvent. The solvent may be an aqueous solvent, but in order to carry out the reaction more mildly, paraffin, ethylene glycol dimethyl ether, diethylene glycol Solvents such as dimethyl ether, triethylene glycol dimethyl ether, toluene, acetonitrile, and ethyl acetate may be used.

[0022]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

[Production Example 1 of Raw Material Alcohol] In the general formula (1), R ¹ ; C ₁₁ H _23- , R ² ;
Synthesis of compounds of H, X; -CONH-, 1; 2, m; 0, n; 3.9 108 g (0.5 mol) of methyl laurate and 31.5 g (0.52 mol) in a 1 l autoclave Of monoethanolamine and 0.6 g of sodium methylate, and heated under reduced pressure (160 mmHg) at 110 ° C. for 2 hours.
After aging at 60 mmHg and 80 ° C. for 5 hours, generated methanol was completely distilled off. After slowly cooling to room temperature, lauric acid monoethanolamide was obtained. 0.6 to this reaction product
g of sodium methylate was added, and while maintaining the temperature at 100 to 120 ° C., 88 g (2.0 mol) of ethylene oxide was gradually injected over 30 minutes. After the injection, the reaction was continued for about 1 hour.
Aged at 0 ° C. for 6 hours. After neutralizing the reaction product with acetic acid, ion-exchanged water was added and heated to separate the cloud point. The number of moles of ethylene oxide added was 3.9 mol.

[Production Example 2 of Raw Material Alcohol] In the general formula (1), R ¹ ; C ₁₂ H _25- , R ² ;
Synthesis of compounds of H, X; -NHCO-, 1; 2, m; 0, n; 6.0 After stirring, a reflux condenser, a nitrogen blowing tube, a dropping funnel,
185 g in a 1 liter four-necked flask equipped with a thermometer
(1.0 mol) of dodecylamine, and 72 g (1.0 mol) of β-propiolactone were gradually added from a dropping funnel while blowing nitrogen. Since the temperature rises due to heat generation, dropping was performed while maintaining the temperature at 40 ° C. or lower. After completion of the dropwise addition, aging was performed at 50 ° C. for further 4 hours. After cooling the reaction solution, 500 ml of ethyl ether was added to separate an ether phase, and the mixture was washed twice with ion-exchanged water. The ether was distilled off to obtain 221 g (0.86 mol) of N-dotesyl-β-hydroxypropioamide. 128 g (0.5 mol) of the reaction product and 4 g of 20% caustic soda (0.02 mol) were placed in a 500 ml autoclave, stirred under reduced pressure (80 mmHg) at 90 ° C. for 1 hour, and stirred at 100 ° C.
While maintaining the temperature at 110 ° C., 135 g (3.1 mol) of ethylene oxide was gradually injected over 50 minutes. After completion of the press-in, the mixture was aged for about 1 hour. After neutralizing the reaction product, ion-exchanged water was added and heated to separate the cloud point. The number of moles of ethylene oxide added was 6.0 mol.

Next, examples and comparative examples in which the corresponding carboxylic acids are produced using the alcohols and higher alcohol ethoxylates or higher fatty acid monoethanolamides obtained in the above Production Examples 1 and 2 will be described. In addition, the purity test of the produced carboxylic acid was performed by the following method. <Purity test method> The purity test of the carboxylic acid having an amide group and an ether group obtained in the following examples is carried out in accordance with the acid carboxylic acid value of the reaction product (necessary for neutralizing the free fatty acid contained in 1 g of the sample). (Mg of potassium hydroxide) was measured, and the measurement was performed according to the following equation. Purity (%) = [acid value / (56108 / molecular weight of carboxylic acid)] × 100

Example 1 In a 1-liter four-necked flask equipped with a stirrer, a pH meter, a dropping funnel, and a thermometer, 4
1.5 g of the alcohol having an amide group and an ether group obtained in Preparation Example 1, 0.3 g of 2,2,6,6-tetramethyl-piperidine-1-oxyl, and 12 ml of a 10% aqueous potassium bromide solution And 15 ml of 5% sodium hypochlorite is added dropwise while stirring at 15 ° C., and the pH is adjusted with 20% sulfuric acid.
Was adjusted to 8.6. While maintaining the reaction temperature at 15 ° C., 350 ml of 5% sodium hypochlorite was further added dropwise.
At this time, the pH was adjusted to 9 or less as needed. After the completion of the dropwise addition, the mixture was stirred for 1 hour, the temperature was gradually raised, and the mixture was further stirred at 35 ° C. for 3 hours. The pH of the resulting reaction mixture was adjusted to 2 and heated to separate the upper layer. Carboxylic acid groups in the vicinity of 1725 cm ^-1 in the infrared absorption spectrum, 1635 cm ^-1 in the amide group, the absorption of ether group in 1,120 cm ^-1 were observed. The purity of the carboxylic acid determined from the acid value was 98%.

Example 2 5-11 flasks equipped with a stirrer, a pH meter, a dropping funnel and a thermometer were charged with 5
2.1 g of the alcohol having an amide group and an ether group obtained in Preparation Example 2 and 0.6 g of 4-hydroxy-2,2,6,
6-tetramethyl-piperidine-1-oxyl, 10 m
One liter of a 10% aqueous sodium bromide solution was added, 15 ml of 5% sodium hypochlorite was added dropwise while stirring at 20 ° C., and the pH was adjusted to 8.6 with 20% sulfuric acid. While maintaining the reaction temperature at 20 ° C., 300 ml of 5% sodium hypochlorite was further added dropwise. At this time, the pH was adjusted to 9 or less as needed. After the completion of the dropwise addition, the mixture was stirred for 1 hour, the temperature was gradually increased, and the mixture was further stirred at 40 ° C. for 3 hours. The pH of the resulting reaction mixture was adjusted to 2 and heated to separate the upper layer. The purity of the carboxylic acid determined from the acid value was 97%.

Example 3 In a 1-liter four-necked flask equipped with a stirrer, a pH meter, a dropping funnel, and a thermometer, 4
1.5 g of the alcohol having an amide group and an ether group obtained in Preparation Example 1 and 0.3 g of 2,2,6,6-tetramethyl-piperidine-1-oxyl, 8 ml of a 10% aqueous potassium chloride solution and Add 50 ml of acetonitrile, add 15
After 15 ml of 5% sodium hypochlorite was added dropwise while stirring at ℃, the pH was adjusted to 8.6 with 20% sulfuric acid. While maintaining the reaction temperature at 15 ° C., 330 ml of 5% sodium hypochlorite was further added dropwise. At this time, if necessary, pH
Was adjusted to 9 or less. After the completion of the dropwise addition, the mixture was stirred for 1 hour, the temperature was gradually raised, and the mixture was further stirred at 35 ° C. for 3 hours. After the solvent of the obtained reaction mixture was distilled off, the pH was adjusted to 2, and the mixture was heated to separate the upper layer. The purity of the carboxylic acid determined from the acid value was 99%.

Example 4 In a 1-liter four-necked flask equipped with a stirrer, a pH meter, a funnel, and a thermometer, 4
0.6 g of polyoxyethylene (P = 5) lauryl ether and 0.4 g of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, 10 ml of 10% aqueous potassium bromide solution and 50 ml Acetonitrile, and 15 ml of 5% sodium hypochlorite is added dropwise while stirring at 15 ° C., and the pH is adjusted to 8.6 with 20% sulfuric acid. While maintaining the reaction temperature at 15 ° C, a further 350 ml of 5
% Sodium hypochlorite is added dropwise. At this time, the pH is adjusted to 9 or less as necessary. After completion of the dropwise addition, the mixture is stirred for 1 hour, the temperature is gradually raised, and the mixture is further stirred at 35 ° C. for 4 hours. After distilling off the solvent of the obtained reaction mixture, the pH was adjusted to 2
And heat to separate the upper layer. In the infrared absorption spectrum, a carboxylic acid group near 1720 cm ^-1 and 1120 c
Absorption of an ether group was observed around m ^-1 . The purity of the carboxylic acid determined from the acid value was 97%.

Example 5 A 1-liter four-necked flask equipped with a stirrer, a pH meter, a dropping funnel, and a thermometer was charged with 2
4.3 g of lauric acid monoethanolamide and 0.3 g
2,2,6,6-tetramethyl-piperidine-1-oxyl, 5 ml of 10% aqueous sodium bromide solution and 50 m
of acetonitrile and stirring at 15 ° C.
After dropwise addition of 5% sodium hypochlorite 5%, the pH is adjusted to 8.6 with 20% sulfuric acid. While maintaining the reaction temperature at 15 ° C., 330 ml of 5% sodium hypochlorite is further added dropwise. At this time, the pH is adjusted to 9 or less as necessary. Stir for 1 hour after dropping, gradually raise the temperature to 35 ° C
And continue stirring for another 3 hours. After evaporating the solvent of the obtained reaction mixture, the pH is adjusted to 2, and the mixture is heated to separate the upper layer. In the infrared absorption spectrum, absorption of a carboxylic acid group was observed around 1720 cm ^-1 and absorption of a carboxylic acid was found near 1670 cm ^-1 . The purity of the carboxylic acid determined from the acid value is 9
4%.

Comparative Example 1 In Example 1, 2,2,6,6
The reaction was carried out in the same manner, except that -tetramethyl-piperidine-1-oxyl was not added. The purity of the carboxylic acid determined from the acid value was 18%.

Comparative Example 2 The reaction was carried out in the same manner as in Example 1 except that sodium hypochlorite was not added. The purity of the carboxylic acid determined from the acid value was 0%.

Comparative Example 3 The reaction was carried out in the same manner as in Example 1, except that sodium bromide was not added. The purity of the carboxylic acid determined from the acid value was 91%.

Comparative Example 4 The reaction was carried out in the same manner as in Example 1, except that sodium bromide was not used and sodium bicarbonate was used as a pH adjuster. (Based on the method of JP-A-5-194334) The purity of the carboxylic acid determined from the acid value was 90%.

Comparative Example 5 The same method as in Example 4 was carried out except that potassium bromide was not added. The purity of the carboxylic acid determined from the acid value was 89%.

Comparative Example 6 The reaction was carried out in the same manner as in Example 5 except that sodium bromide was not added. The purity of the carboxylic acid determined from the acid value was 85%.

[0037]

According to the present invention, the desired carboxylic acid can be produced economically with high purity. And the carboxylic acid or a salt thereof obtained by the present invention is, for example,
Amide ether carboxylic acid, alkoxy ether carboxylic acid, alkenyl oxy ether carboxylic acid, or salts thereof are less irritating to the skin and are excellent surfactants for detergents having excellent foaming properties, for shampoos, body shampoos, tableware and vegetables. Useful for detergents, fashionable wear detergents, soaps, etc.

Claims (1)

[Claims] An alcohol having an amide group and / or an alkoxy group or an alkenyloxy group is oxidized with a chlorine-based oxidizing agent in the presence of a nitroxide radical and an alkali metal halide or an alkaline earth metal halide. Process for producing amide- and / or alkoxy- or alkenyloxy-carboxylic acids or salts thereof.