JPS588388B2 - Jibenza Middle Ino Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a general formula (in formula (6), X1, X2, X3, X4 and
5 is hydrogen, chlorine, bromine, or iodine atom, or an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, or an alkylthio group having 1 to 10 carbon atoms, respectively.
The present invention relates to a method for producing dibenzamides represented by 0 mono- or dialkylamino groups, ditro groups, or aryl groups.

Benzonitriles have the ability to trap metal ions and form chelates (e.g. INORG, CHEM., B
, 470-4 (1969)); chelates of europium and other metals exhibit fluorescence and are therefore used in fluorescent paints (
U.S. Patents 3398099, 3422023, 35513
45 etc.), and also has properties that are useful as agricultural chemicals, medicines, and synthetic intermediates.

Dibenzamides are usually produced by reacting penzamides with halogenated benzoyls.

This method requires expensive benzoyl halides and also requires chlorinated substances (eg, amines) to capture hydrogen halides, which are reaction byproducts.

It has been reported that dibenzamides can also be obtained by treating aromatic nitriles with a mixture of sulfuric acid and phosphoric anhydride, but in this case many by-products are produced and purification is not easy.

The present invention was achieved by discovering that the desired product can be easily obtained in high yield by reacting aromatic nitriles with sulfuric anhydride and then with water.

In the present invention, the aromatic nitriles used as raw materials have the general formula (I) (in formula (I), X1, X2, X3, X4 and
represents the same meaning as in formula (II)).

To carry out the method of the present invention, aromatic nitriles and sulfuric anhydride are mixed at -10 to 50°C, preferably from 0 to 25°C.
After reacting for 20 hours, excess sulfuric anhydride may be evaporated, water may be added to the remaining solid, and the reaction may be carried out at 0 to 100°C for 1 to 2 hours.

In the case of a target product having low solubility in water, the target product can be obtained by cooling the aged product after the reaction with water, filtering off the precipitated solid, and washing with water.

This crude product can be purified by recrystallization.

As a solvent for recrystallization, benzene, toluene, methanol, ethanol, methanol-water, ethanol-water, etc. can be used.

If a large amount of the target substance is dissolved in the aqueous phase, extract it using an extraction solvent such as ether after the reaction with water is completed.
The target object can be recovered.

A solvent can be used when aromatic nitriles and sulfuric anhydride are reacted, and particularly when the aromatic nitriles are solid at around room temperature, it is desirable to dissolve them in a solvent and use them as a solution.

The solvent must be inert to sulfuric anhydride under the reaction conditions of the present invention, and must be inert to halogenated hydrocarbons (
For example, dichloromethane), ethers (for example, dioxane), etc. are preferred.

Sulfuric anhydride can be added to the reaction system in a solid, liquid or gaseous state.

When added in a liquid state, it may be used without being diluted, but it may also be used as a solution diluted with the above-mentioned inert solvent (halogenated hydrocarbon, ether, etc.).

When adding it to the reaction system in a gaseous state, it may be charged undiluted, or it may be diluted with an inert gas such as air, nitrogen, or carbon dioxide.

When an inert solvent is used in the reaction with sulfuric anhydride,
The reaction with water is carried out after evaporating off the excess sulfuric anhydride and simultaneously or separately after evaporating off the inert solvent.

Although it is unknown what kind of intermediate is produced by the reaction of aromatic nitriles and the like with sulfuric anhydride, it is thought that 2 moles of the aromatic nitriles and 1 mole of sulfuric anhydride are involved in the reaction.

Therefore, sulfuric anhydride is used in an excess amount of 0.5 mole or more per mole of aromatic ethryls.

Further, in the reaction between this intermediate and water, water not only participates in the reaction, but also acts as a reaction medium and a diluent for sulfuric acid produced as a by-product of the reaction.

Therefore, the amount of water used is 5 mol or more per 1 mol of the aromatic nitrile as the initial raw material, but generally even if a sufficiently excess amount is used, there will be no adverse effect on the reaction.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 Anhydrous sulfuric acid 12,5P (0.156 mol) was dissolved in 100 ml of dichloromethane, and 16.0 g of penzonitrile (16.0 g) was dissolved in 100 ml of dichloromethane.
A solution consisting of 0.155 mol) and 40 ml of dichloromethane was added dropwise thereto at 5-10°C.

After stirring for 1 hour at room temperature and standing for 16 hours, the anhydrous sulfuric acid and dichloromethane were then evaporated off under reduced pressure.

Add 150rrLl of water to the remaining yellow solid and bring to 70~
After stirring at 80°C for 1 hour, the solid turned white.

This suspension was cooled to room temperature, filtered, and the solids were washed with water.

The yield of dried solid was 15.4 g (88% yield).

When a portion was recrystallized from water, needle-shaped crystals were obtained, and the melting point was 147-8°C (literature value: 148°C).

In addition, the elemental analysis value of this crystal is (C74.51%, H4
．． 99%, N6.33%) is the calculated value as dibenzamide (C74.65%, H4.92%, N6,22%)
) was in good agreement.

Example 2 11.9 g (0.149 mol) of anhydrous sulfuric acid was dissolved in 100 rrLl of dichloromethane, and 22.0 P (0.149 mol) of m-nitrobenzonitrile and 100 ml of dichloromethane were dissolved.
ml of the solution was added dropwise thereto at 5-10°C.

After stirring at room temperature for 1 hour, the mixture was left to stand for 16 hours.

Dichloromethane and excess sulfuric anhydride were evaporated off under reduced pressure, and 150 ml of water was added to the remaining brown solid.
It was stirred at ℃ for 1 hour.

The mixture was cooled to room temperature, filtered, washed with water, and dried to obtain a solid of 16.21 (0-0514 mol, yield 69
%)Met.

The melting point of colorless, scaly crystals obtained by recrystallization from ethanol was 191°C.

Elemental analysis values are C53.56%, H2.82%, Nl3
．． Calculated as 3,3'-dinitrodibenzamide at 32% (C53.34%, H2.88%, N13.3
3%).

Examples 3 to 10 In the same manner as in Example 2, from the benzonitrile derivatives shown in the second column of Table 1, the corresponding dibenzamides (third column of the same table) were obtained.

Claims (1)

[Scope of Claims] 1 In the general formula (I) (formula ■), Xl, X2, X3, X4 and X5 are each hydrogen, chlorine, bromine or iodine atom, or an alkyl group having 1 to 10 carbon atoms, carbon Aromatic nitriles represented by an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a mono- or dialkylamino group having 1 to 10 carbon atoms, a nitro group, or an aryl group,
In general Ichikawa (formula (6)), which is characterized by reacting with sulfuric anhydride in the presence or absence of an organic solvent inert to sulfuric anhydride, and reacting the resulting reaction product with water, X1, X2, X3, X4 and X5
has the same meaning as in formula (I)).