JP2000273094A - Production of phthalide compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the rapid progress of reaction and to obtain a high purity phthalide compound useful as a coloring agent for a chromogenic recording material at high yield by controlling the foaming state of a reaction liquid when oxidizing a triphenylmethane compound. SOLUTION: When oxidizing a triphenylmethane compound preferably 2-[4,4'- bis(dimethylamino)benzhydryl]-5-dimethylaminobenzoic acid or the like} of formula I (wherein R1-R6 are each an alkyl or the like) in an aqueous medium in the sence of active carbon with an oxidant (preferably air, oxygen or the like), a phthalide compound of formula II is obtained by installing a circulating line outside a reactor and by carrying out the oxidization while circulating the reaction liquid. When returning the reaction liquid circulated to the inside of the reactor, the reaction liquid to be returned is preferably returned by being sprayed from the vapor part of the reaction liquid in the reactor toward the liquid surface and the sprayed liquid preferably consists of liquid drops having their diameter of 0.5-5 cm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phthalide compound useful as a color former for a color recording material.

[0002]

2. Description of the Related Art A 3,3-bisarylphthalide compound having an amino group, 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), is used as a color forming agent for forming a blue color. Widely used for copying paper, thermal recording paper and the like. Production methods for obtaining a phthalide compound by oxidizing a triarylmethane compound include those described in JP-A-62-184601, JP-A-55-120562, and JP-A-02-4716.
The method described in Japanese Patent Publication No. 0 and the like is known.

[0003]

An object of the present invention is to control the foaming state of a reaction solution when producing a phthalide compound by oxidation from a triphenylmethane compound so that the reaction can proceed extremely quickly. In other words, an object of the present invention is to provide an industrially useful production method capable of obtaining a phthalide compound with high purity and high yield.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, when circulating the reaction solution and returning the circulating solution to the inside of the reactor, the droplet diameter was controlled. The inventors have found that by spraying onto the surface of the foamed reaction solution, it is possible to control the reaction so that the reaction cannot be continued due to the foaming state, and have completed the present invention.

That is, the present invention is as follows. 1) General formula (1)

Embedded image [In the formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶
Represents an alkyl group, and R ¹ and R ² , R ³
And R ⁴ and R ⁵ and R ⁶ may be linked to each other to form a heterocyclic ring together with the nitrogen atom. The method for producing a phthalide compound represented by the general formula (2)

Embedded image [In the formula (2), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶
Represents an alkyl group, and R ¹ and R ² , R ³
And R ⁴ and R ⁵ and R ⁶ may be linked to each other to form a heterocyclic ring together with the nitrogen atom. When oxidizing the triphenylmethane compound represented by the formula (1) with an oxidizing agent in the presence of activated carbon in an aqueous solvent, a circulation line is provided outside the reactor, and the reaction is performed while circulating the reaction solution. For producing a phthalide compound. 2) The production method according to the above 1), wherein, when returning the circulating reaction solution to the inside of the reactor, the reaction solution is injected from a gas phase portion above the reaction solution toward the surface of the reaction solution. 3) The method according to 3) above, wherein the state of the liquid being ejected is a state where the droplet diameter is 0.5 to 5 cm.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The production method of the present invention will be specifically described below. The substituents R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ in the general formulas (1) and (2) each represent an alkyl group, and these alkyl groups are represented by R ¹ , R ² and R ^3. And R ⁴ and R ⁵ and R ⁶ may be linked to each other to form a heterocyclic ring together with the nitrogen atom. R ¹
If to R ⁶ is an alkyl group, preferably 1 to carbon atoms
And is more preferably a lower alkyl group having 1 to 4 carbon atoms. Specific examples include a methyl group, n
-Propyl group, iso-propyl group, n-butyl group, i
so-butyl group, sec-butyl group, n-pentyl group,
Examples include an iso-pentyl group, a neo-pentyl group, an n-hexyl group, an iso-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, and the like. Also,
R ¹ and R ² , R ³ and R ^4, and R ⁵ and R ⁶ are mutually connected to form a heterocyclic ring formed with a nitrogen atom, for example, a piperidino group, a piperazino group, a pyrrolidino group, a morpholino group, and the like. But preferably a piperidino group,
A pyrrolidino group.

The triphenylmethane compound represented by the general formula (2) used in the method of the present invention (hereinafter sometimes abbreviated as a leuco compound) is preferably 2-phenylmethane compound.
[4,4'-bis (dimethylamino) benzhydryl]
-5-dimethylaminobenzoic acid, 2- [4,4'-bis (diethylamino) benzhydryl] -5-dimethylaminobenzoic acid, 2- [4,4'-bis (dimethylamino) benzhydryl] -5-diethylaminobenzoate acid,
2- [4,4'-bis (ethylmethylamino) benzhydryl] -5-dimethylaminobenzoic acid, 2- [4
4'-bis (diethylamino) benzhydryl] -5-
Diethylaminobenzoic acid, 2- (4-diethylamino-4'-dimethylaminobenzhydryl) -5-diethylaminobenzoic acid, 2- [4,4'-bis (di-n-propylamino) benzhydryl] -5-dimethyl Aminobenzoic acid, 2- [4,4′-bis (diisopropylamino) benzhydryl] -5-dimethylaminobenzoic acid,
2- [4,4'-bis (di-n-butylaminobenzhydryl) -5-dimethylaminobenzoic acid;
4'-bis (diisobutylamino) benzhydryl]-
5-dimethylaminobenzoic acid, 2- (4-di-n-butylamino-4′-diethylaminobenzhydryl) -5
-Diethylaminobenzoic acid, 2- [4,4'-bis (di-n-butylamino) benzhydryl] -5-n-butylaminobenzoic acid, 2- [4,4'-bis (di-sec
-Butylamino) benzhydryl] -5-dimethylaminobenzoic acid, 2- [4,4'-bis (pyrrolidino) benzhydryl] -5-dimethylaminobenzoic acid, 2-
[4,4'-bis (piperidino) benzhydryl] -5
-Dimethylaminobenzoic acid and the like.

Preferred specific examples of the phthalide compound represented by the general formula (1) which can be produced by the present invention include 3,3-bis (4-dimethylaminophenyl)-, which corresponds to the above general formula (2). 6-dimethylaminophthalide, 3,3
-Bis (4-diethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (4-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (4-ethylmethylaminophenyl) -6 -Dimethylaminophthalide, 3,3-bis (4-diethylaminophenyl) -6-diethylaminophthalide, 3- (4-diethylaminophenyl) -3- (4-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (4-di-n-propylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (4-diisopropylaminophenyl) -6-dimethylaminophthalide, 3,
3-bis (4-diisobutylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (4-di-n-butylaminophenyl) -6-diethylaminophthalide,
3- (4-di-n-butylaminophenyl) -3- (4
-Diethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (4-di-n-butylaminophenyl) -6-di-n-butylaminophthalide, 3,3-bis (4-di-sec -Butylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (4-pyrrolidinophenyl) -6-dimethylaminophthalide, 3,3-bis (4-piperidinophenyl) -6-dimethyl Aminophthalide and the like can be mentioned.

The term "aqueous solvent" as used herein means a solvent containing 80% by weight or more of water, and refers to water and a mixed solvent of water and an organic solvent. As the organic solvent that can be used by mixing with water, alcohol solvents such as isopropyl alcohol and n-butyl alcohol, and aromatic hydrocarbon solvents such as benzene and toluene are preferable. In a mixed solvent, if the organic solvent is contained in an amount exceeding 20% by weight, the reaction rate may tend to decrease.
A solvent containing the above is preferably used. The amount of the solvent used is 2 to 20 times the weight of the leuco compound, preferably 5 to 1 times.
5 times the weight.

The preferred oxidizing agent used in the present invention is at least one selected from the group consisting of air, oxygen, hydrogen peroxide, and a mixture of oxygen and an inert gas. Are more preferred. These are introduced into the reaction solution at atmospheric pressure or under pressure. The amount of the oxidizing agent to be used is, in the case of oxygen or an oxygen-containing gas, at least an equimolar amount of oxygen with respect to the triphenylmethane compound of the general formula (2) used in the reaction. In the case of hydrogen peroxide, It is preferable to use 1 to 1.2 times mol of the leuco compound used for the reaction. If the amount is less than 1 mol, the reaction is not completed, and if it is more than 1.2 mol, a large amount of decomposition products is generated. When oxygen or an oxygen-containing gas is used in combination with hydrogen peroxide, the number of moles of hydrogen peroxide is preferably equal to or less than the number of moles of the leuco compound used in the reaction. This is because even if oxygen is used in a large amount, a decomposition product is not generated much, but a large amount of hydrogen peroxide increases the decomposition product.

The activated carbon used in the present invention includes powdered coal, granular coal, spherical coal, crushed coal and granulated coal.
For example, Carborafin manufactured by Takeda Pharmaceutical Co., Ltd.
Shirasagi series (strong, refined, properties, A, B, C, G,
M, P, S, DC, KL, W, EH, X-7000, X
-7100), Taiko activated carbon manufactured by Nimura Chemical Industry Co., Ltd. (SGF, SA-1000, K, KA, A, KI, A
P, RC, S5, P, W, SGS, SGA, SG, SG
P, CG48B, CG830B, CW830B, CW3
50B, CW612G, CW816G), PM series (PM-PA, PM-P) manufactured by Mitsui Pharmaceutical Co., Ltd.
w, PM-PWI, PM-WA, PM-KI, PM-Y
O, PM-KS, PM-MO, PM-AA, PM-P
E, PM-CR, PM-WA, PM-SX, PM-F
Z, APC, F-300, F-400 and the like.
Further, activated carbon to which a metal compound is added or supported can also be used. For example, FCA, Sulfsorb, a palladium / carbon supported catalyst, a platinum / carbon supported catalyst manufactured by Toyo Calgon Co., Ltd., and the like.

In addition, any other activated carbon produced from wood, charcoal, coconut shell, coal or the like as a raw material can also exhibit a catalytic effect. Among them, Egret-A, Egret-B, Egret-C, Egret-D, Egret-M, Egret-P, APC, CP
G and the like exhibit particularly excellent catalytic effects. The more the amount of activated carbon used, the greater the effect of accelerating the oxidation rate is seen. However, from the viewpoint of workability in removing activated carbon and economical aspects, 5 to 100 wt% of the leuco compound used in the reaction is used.
Is preferred.

In the present invention, an acid or a base may be used in order to make the reaction proceed smoothly. Examples of the acid used include mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid, and organic acids such as p-toluenesulfonic acid, methanesulfonic acid, acetic acid, and formic acid. As the base used, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,
Inorganic bases such as sodium hydrogencarbonate, potassium hydrogencarbonate, sodium methylate, potassium methylate, sodium ethylate, potassium ethylate, pyridine, triethylamine, 1,8-diazabicyclo [5,4
0] -7-undecene, 1,5-diazabicyclo [5,
3,0] -5-nonene, 1,4-diazabicyclo [2,
2,2] octane and guanidine.

The method of the present invention can be carried out under normal pressure or under pressure. The reaction temperature is preferably from 40 to 120C, more preferably from 70 to 100C. The reaction time depends on the reaction temperature, reaction pressure conditions, the amount of activated carbon used and its type, but is 3 to 20 hours when the reaction is carried out at 90 to 95 ° C. under normal pressure. Under the same temperature and pressure, it can be shortened to 1 to 6 hours. For foaming during the reaction, circulate the reaction solution,
When returning the circulating liquid into the reactor, the droplet diameter is controlled, and by spraying on the surface of the bubbling reaction solution, the bubbling state is controlled and a stable reaction is continued without using an antifoaming agent It is possible to do. Droplet size 0.5 ~ 5c
m, preferably 1-2 cm. Outside the range of 0.5 to 5 cm, the defoaming effect is extremely reduced. As a device that controls the droplet diameter and sprays it onto the surface of the bubbling reaction solution,
For example, a triangular pyramid (shower faucet) provided with a large number of pores (2 to 7 m / m) on the bottom surface is attached to the end of a pipe returning from the circulation line to the reactor, and is sprayed on the surface of the foamed reaction solution. The size of the droplet diameter can be controlled by changing the diameter of the pores at the bottom of the triangular pyramid. The relationship between the diameter of the pore and the size of the droplet diameter is as follows: When the diameter of the pore is 3 m / m, the size of the droplet diameter is 1-2 c
m, 2-3 cm at 5 m / m.

The obtained phthalide compound may be further purified using a solvent as required. Solvents used for purification include alcohol solvents such as methanol, ethanol, and isopropyl alcohol, benzene, toluene,
Aromatic hydrocarbon solvents such as xylene, dichloromethane,
Halogenated hydrocarbon solvents such as chloroform, dichloroethane and chlorobenzene, ether solvents such as diethyl ether and tetrahydrofuran, ketone solvents such as methyl isobutyl ketone and diisobutyl ketone, or a combination thereof are preferred.

[0016]

EXAMPLES The present invention will be described more specifically with reference to examples. Example 1 2- [4, 150 L SUS reactor
4′-bis (dimethylamino) bezhydryl] -5-dimethylaminobenzoic acid (7.1 kg) and water (75 kg)
And dispersed by adding Shirasagi-C (Takeda Pharmaceutical Co., Ltd.)
8 kg and 49 g of NaOH (700 g) were added, the mixture was stirred at 90 to 95 ° C. under atmospheric pressure, and air was blown into the system at a flow rate of 1 Nm ³ / Hr for 9 hours. Before the start of the oxidation reaction with air, a part of the reaction solution was once drawn out of the reactor, and the reaction solution was circulated at a rate of 300 L / Hr through a line returning to the reactor. The circulating liquid has pores (3
m / m), and the liquid was circulated around the liquid surface such that the diameter of the liquid droplets became 1 to 2 cm. Foaming in the middle of the reaction was confirmed by the looking glass on the upper part of the reactor that the reaction was maintained without defoaming with the circulating liquid and reaching the upper part of the reactor. The reaction mass was filtered, and the obtained cake was slurried in water.
After adding kg to completely dissolve the reaction mass, the activated carbon was filtered. The filtrate was neutralized with a 49% aqueous NaOH solution until pH = 7, and the precipitated crystals were filtered, washed, and dried to obtain 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide. 6.81 kg (yield 9
5.0%). At this time, the amount of the reaction by-product was 1.9%, and the reaction selectivity was 98.0%.

(Example 2) The reaction was carried out under the same conditions as in Example 1 except that the pressure was 0.5 MPa. The reaction time for air oxidation was 4 hours. One end of the reaction solution is drawn out of the reactor, and 300 L / Hr
The circulation of the reaction solution was carried out in the same manner at the speed described above. The circulating liquid was ejected from a shower faucet provided with a fine hole (5 m / m) at the end of the circulating line, and circulated to the liquid surface such that the diameter of the droplet became 2 to 3 cm. Foaming during the reaction tended to be higher in the bubble position than under atmospheric pressure, but the reaction was maintained without defoaming with the circulating liquid and reaching the upper part of the reactor. It could be confirmed from the looking glass in the same manner as in Example 1. After completion of the reaction, the same post-treatment as in Example 2 was performed to obtain 6.83 kg of the desired 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (yield 95.2%). . At this time, the amount of the reaction by-product was 1.7%, and the reaction selectivity was 98.2%.

Comparative Example 1 A reaction was performed under the same conditions as in Example 1 except that the reaction solution was not circulated. Although the foam rose near the looking glass at the top of the reactor, the reaction was continued to obtain the final product. 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide 6.3
8 kg were obtained. (Yield: 89.0%) At this time, the amount of the reaction by-product was 6.6%, and the reaction selectivity was 93.0.
%Met.

(Comparative Example 2) A reaction was carried out under the same conditions as in Example 2 except that the reaction solution was not circulated. Since the foam rose completely to the looking glass at the top of the reactor,
It ended in 0 minutes. The starting material, 2- [4,4'-bis (dimethylamino) bezhydryl] -5-dimethylaminobenzoic acid, was analyzed and the reaction was not completed.

[0020]

According to the method of the present invention, a phthalide compound can be produced in a short time and in a high yield by oxidizing a triphenylmethane compound (leuco compound).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeo Asano 1 Goseicho, Omuta-shi, Fukuoka Pref. Yamamoto Kasei Co., Ltd. (72) Inventor Junichi Ishiyama 30 Asamuta-cho, Omuta-shi, Fukuoka, Japan Mitsui Chemicals, Inc. (72) Inventor Satoshi 30-Amuta-cho, Omuta-shi, Fukuoka, Japan Mitsui Chemicals, Inc. No. 30 Asmuta-cho, Omuta-shi, Iwate Mitsui Chemicals, Inc. F-term (reference) 4C037 RA03

Claims (3)

[Claims] 1. A compound of the general formula (1) [In the formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶
Represents an alkyl group, and R ¹ and R ² , R ³
And R ⁴ and R ⁵ and R ⁶ may be linked to each other to form a heterocyclic ring together with the nitrogen atom. In the method for producing a phthalide compound represented by the general formula (2): [In the formula (2), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶
Represents an alkyl group, and R ¹ and R ² , R ³
And R ⁴ and R ⁵ and R ⁶ may be linked to each other to form a heterocyclic ring together with the nitrogen atom. When oxidizing the triphenylmethane compound represented by the formula (1) with an oxidizing agent in the presence of activated carbon in an aqueous solvent, a circulation line is provided outside the reactor, and the reaction is performed while circulating the reaction solution. For producing a phthalide compound. 2. The production method according to claim 1, wherein when the circulating reaction solution is returned to the inside of the reactor, the reaction solution is jetted from the gas phase above the reaction solution toward the surface of the reaction solution. 3. The state of the liquid being ejected has a droplet diameter of 0.5.
3. The method according to claim 2, wherein the state is about 5 cm.