JPH1171366A - Production of phthalide compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically obtain the subject compound capable of extremely rapidly reacting, not causing a waste water treatment problem after the reaction and useful as a coupler for color development type recording materials by performing the reaction in the presence of activated carbon. SOLUTION: This method for producing a phthalide compound of formula II (R<1> -R<6> are each an alkyl or the like) [e.g. 3,3-bis(4-dimethylaminophenyl)-6- dimethylaminophthalide] comprises oxidizing a triphenylmethane compound of formula I e.g. 2-[4,4'-bis(dimethylamino)benzhydryl]-5-dimethylaminobenzoic acid} with an oxidizing agent, preferably one kind of compound selected from air, oxygen, hydrogen peroxide and the mixtures of oxygen with inactive gases in the presence of activated carbon in an aqueous solvent.

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, in particular, 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone) is a color former which develops a blue color. Are widely used in pressure-sensitive copying paper, heat-sensitive recording paper, and the like.
As a method for producing a phthalide compound by oxidizing a triarylmethane compound, JP-A-62-184601, JP-A-55-120562, and JP-A-02-4 are disclosed.
The method described in JP-A-7160 is known. In these production methods, as the reaction proceeds, the alkali concentration in the reaction system increases, and unreacted raw materials remain forever, and after the metal compound added to promote oxidation is completed, the phthalide compound is filtered off. However, there is a problem in that the wastewater is contained in the wastewater when washed, thereby increasing the cost of wastewater treatment.

[0003]

An object of the present invention is to produce a phthalide compound from a triphenylmethane compound by an oxidation reaction, the reaction proceeds very quickly, and there is no problem of wastewater treatment after the reaction is completed. To provide an efficient manufacturing method.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, when the reaction is performed in the presence of activated carbon, the reaction proceeds smoothly and is completed in a short time. And completed the present invention. That is, the present invention relates to the 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; R ¹ , R ² , R
³ and R ⁴ and R ⁵ and R ⁶ are linked to each other,
A heterocyclic ring may be formed together with the nitrogen atom. In the production of the phthalide compound represented by

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; R ¹ , R ² , R
³ and R ⁴ and R ⁵ and R ⁶ are linked to each other,
A heterocyclic ring may be formed together with the nitrogen atom. A phthalide compound represented by the general formula (1), wherein the triphenylmethane compound represented by the general formula (1) is oxidized with an oxidizing agent in an aqueous solvent in the presence of activated carbon.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The production method of the present invention is specifically described below.
Explain the law. Substitution in general formulas (1) and (2)
Group R¹, R^Two, R^Three, R^Four, R^FiveAnd R⁶Each
Represents an alkyl group, and these alkyl groups are represented by R¹And R
^Two, R ^ThreeAnd R^FourAnd R^FiveAnd R⁶Are connected to each other
It may combine to form a heterocyclic ring together with the nitrogen atom. R¹
~ R⁶Is an alkyl group, preferably has 1 to 1 carbon atoms
8 alkyl groups, more preferably having 1 to 4 carbon atoms.
It is a lower alkyl group. Specific examples include methyl groups,
Group, n-propyl group, iso-propyl group, n-butyl
Group, iso-butyl group, sec-butyl group, n-pen
Tyl group, iso-pentyl group, neo-pentyl group, n
-Hexyl group, iso-hexyl group, n-heptyl group,
n-octyl group, 2-ethylhexyl group and the like.
You. Also, R¹And R^Two, R^ThreeAnd R^FourAnd R^FiveAnd R⁶But
Each is linked together to form a complex formed with the nitrogen atom
Examples of the ring include a piperidino group, a piperazino group, a pyrrolidine
And a morpholino group.
A lysino group and 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-dimethylaminobenzoic acid, 2- [4,4 ' -Bis (diisopropylamino) benzhydryl] -5-dimethylaminobenzoic acid,
2- [4,4′-bis (di-n-butylamino) benzhydryl] -5-dimethylaminobenzoic acid, 2- [4
4'-bis (diisobutylamino) benzhydryl]-
5-dimethylaminobenzoic acid, 2- [4,4'-bis (di-n-butylamino) benzhydryl] -5-diethylaminobenzoic acid, 2- (4-di-n-butylamino-4'-diethylaminobenz (Hydryl) -5-diethylaminobenzoic acid, 2- [4,4'-bis (di-n-butylamino) benzhydryl] -5-di-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-di-n-butylaminophenyl) -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,
Examples thereof include 3,3-bis (4-pyrrolidinophenyl) -6-dimethylaminophthalide and 3,3-bis (4-piperidinophenyl) -6-dimethylaminophthalide.

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, K1, 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-PE, PM-CR, PM-WA, PM-S
X, PM-FZ, PM-SAY) and CAL, CPG, APC, F-300, F- manufactured by Toyo Calgon Co., Ltd.
400 and the like. Further, activated carbon having a metal compound impregnated and supported thereon can also be used. For example,
FCA, Sulfsorb, manufactured by Toyo Calgon Co., Ltd.
And a palladium / carbon supported catalyst, a platinum / carbon supported catalyst, 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 hydrogen carbonate, potassium hydrogen carbonate, sodium methylate, potassium methylate, sodium ethylate and potassium ethylate, pyridine, triethylamine, 1,8-diazabicyclo [5,4
0] -7-undecene, 1,5-diazabicyclo [4,
3,0] -5-nonene, 1,4-diazabicyclo [2,
2,2] organic bases such as 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. If foaming is severe during the reaction, 2-ethylhexanol or polyethylene glycol-based antifoaming agent, isopropyl alcohol, n-
Alcohols such as butyl alcohol, and aromatic hydrocarbon solvents such as benzene and toluene may be added in small amounts.

The obtained phthalide compound may be further purified using a solvent, if necessary. Solvents used for purification include alcohol solvents such as methanol, ethanol, and isopropyl alcohol; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; and halogenated hydrocarbon solvents such as dichloromethane, chloroform, dichloroethane, and chlorobenzene. , Diethyl ether, tetrahydrofuran and other ether solvents, methyl isobutyl ketone, diisobutyl ketone and other ketone solvents, and combinations thereof are preferred.

[0016]

The present invention will be described more specifically with reference to the following examples. (Example 1) In a 500 ml reaction flask, 2- [4,
4'-bis (dimethylamino) benzhydryl] -5-
Dimethylaminobenzoic acid 21.5 g (purity 97.0%)
And 250 g of water was added to disperse the mixture into this.
C (manufactured by Takeda Pharmaceutical Co., Ltd.) (21.5 g) and 2.0 g of a 49% aqueous solution of NaOH were added thereto, and the mixture was stirred at 90 to 95 ° C. and air was added at 400 ml / min. At a flow rate of 9 hours into the reaction system. After completion of the reaction, the reaction mass was filtered, and the obtained filter cake was slurried in water.
After adding 9.5 g to completely dissolve the reaction mass, the activated carbon was filtered. The filtrate was neutralized with a 49% aqueous solution of NaOH until pH = 7.0, and the precipitated crystals were filtered, washed, and dried to give 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide. 20.1 g (95.4% yield) was obtained. At this time, the amount of the reaction by-product was 1.5%, and the reaction selectivity was 98.4%.

(Example 2) In a 500 ml autoclave, 17.1 g of 2- [4,4'-bis (dimethylamino) benzhydryl] -5-dimethylaminobenzoic acid was charged, and 150 g of water was added to disperse the mixture. And this is Shirasagi-C
3.4 g and 1.63 g of 49% aqueous NaOH solution were added,
The reaction was carried out at 100 ° C. for 3 hours under an air pressure of 15 kg / cm ² . After completion of the reaction, the same post-treatment as in Example 1 was carried out to obtain the desired 3,3-bis (4-dimethylaminophenyl) -6.
16.1 g (95% yield) of dimethylaminophthalide was obtained. At this time, the amount of the reaction by-product was 1.3%,
The reaction selectivity was 98.7%.

Comparative Example 1 The same operation as in Example 1 was carried out except that 1.2 g of copper sulphate pentahydrate was used in place of the activated carbon, and 3,3-bis (4-dimethylaminophenyl) 19.1 g (yield: 83.2%) of -6-dimethylaminophthalide was obtained. At this time, the amount of the reaction by-product was 6.0%, and the reaction selectivity was 90.2%.

Comparative Example 2 The same operation as in Example 1 was performed except that activated carbon and a 49% aqueous NaOH solution were not used. Even after 7.5 hours, the reaction hardly proceeded.

Comparative Example 3 The same operation as in Example 1 was performed except that no activated carbon was used. Since the reaction hardly progressed 24 hours after the start of the reaction, the reaction was stopped and post-treatment was performed. Thus, 11.2 g (yield: 53%) of 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide was obtained.

From the above Examples and Comparative Examples, it can be seen that the reaction of oxidizing the leuco compound of the present invention to produce a phthalide compound proceeds rapidly in the presence of activated carbon. The oxidation reaction according to the present invention is extremely slow when the reaction medium is neutral and no catalyst is present. This reaction proceeds by using an oxidation-promoting catalyst as shown in Comparative Example 1. However, in order to industrially produce a phthalide compound by oxidizing a leuco compound, wastewater treatment using a metal catalyst is required. It has been a problem that the technology according to the present invention has not yet been sufficiently solved to further selectively promote the problem and suppress the reaction by-product. As shown in Comparative Example 1, the use of an oxidation-promoting catalyst promotes the oxidation reaction. However, the amount of by-products is large, the reaction selectivity is not good, and the oxidation promotion eluted in the reaction solution after the reaction. There is a catalyst removal problem. This problem is caused by the fact that the oxidation reaction is carried out in the presence of activated carbon as shown in Examples 1 and 2, and Comparative Example 1
The formation of by-products such as those described in Example 1 is reduced, and the reaction proceeds selectively. Furthermore, there is no problem of removing the oxidation promoting catalyst eluted in the wastewater. The method of the present invention, which enables the production of such a phthalide compound quickly and by a method that eliminates the problem of treating the reaction accelerator, is technically and industrially valuable.

[0022]

According to the method of the present invention, it is possible to provide a method for producing a phthalide compound 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, Yu Nishimura, 30 Asamuta-cho, Omuta-shi, Fukuoka Prefecture Mitsui Chemicals, Inc. 72) Inventor Yoshinobu Kanemura 30 Asamuta-cho, Omuta-shi, Fukuoka Prefecture Mitsui Chemicals, Inc.

Claims (2)

[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; R ¹ , R ² , R
³ and R ⁴ and R ⁵ and R ⁶ are linked to each other,
A heterocyclic ring may be formed 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; R ¹ , R ² , R
³ and R ⁴ and R ⁵ and R ⁶ are linked to each other,
A heterocyclic ring may be formed together with the nitrogen atom. ] A method for producing a phthalide compound of the general formula (1), wherein the triphenylmethane compound represented by the formula (1) is oxidized with an oxidizing agent in an aqueous solvent in the presence of activated carbon. 2. The method for producing a phthalide compound according to claim 1, wherein the oxidizing agent is at least one selected from the group consisting of air, oxygen, hydrogen peroxide, and a mixture of oxygen and an inert gas.