JPS6016956A - Production of 3,3' -or 3,4'-diaminobenzophenone - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as a raw material of agricultural chemicals and pharmaceuticals, an intermediate of dyes, etc., in high yield, by reducing a benzophenone compound with formic acid or a formic acid salt in the presence of palladium catalyst, and dechlorinating the reduction product. CONSTITUTION:The objective 3,3'- or 3,4'-diaminobenzophenone is produced by reducing the benzophenone compound of formula (X is Cl substituted to 4 or 6 position; Y is H or Cl, when Y is H, the position of the amino group is 3' or 4', and when Y is 4'-Cl, the amino group is 3') with formic acid or a formic acid salt in the presence of a palladium catalyst (e.g. palladium activated carbon), and dechlorinating the reaction product. The amount of the catalyst is 0.01-10wt% based on the benzophenone compound used as the raw material. The formic acid or the formic acid salt is used in the form of an aqueous solution, and its amount is slight excess to the stoichiometric amount. The solvent is usually the one miscible with water, e.g. alcohol. The reaction is carried out usually at 30-110 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing 3,6'- or lo,4'-diaminobenzophenone, and in particular provides a method that is extremely advantageous for industrial implementation. It is.

More specifically, the general formula (1) (wherein, X represents a chlorine atom and is at the 4- or 6-position. 3'-position or 4'-position.Y
is a chlorine atom at the 4'-position, the amino group is at the 6'-position) is reduced with formic acid or a formate salt in the presence of a palladium catalyst to dechlorinate it. The present invention relates to a method for producing 3+3'-or 4'-diaminobenzophenone.

3. 3'-Diaminobenzophenone and Otsu, 4'-diaminobenzophenone are useful as heat-resistant polymer monomers, agricultural chemicals, dye intermediates, etc., and are particularly important substances as raw materials for heat-resistant polyamides and polyimides. be.

Conventionally, such diaminobenzophenone is produced by reducing the corresponding dinitrobenzophenone. For example, 6,6'-diaminobenzophenone is produced by reducing 6,3'-dinitrobenzophenone with a tin compound in a large amount of hydrochloric acid (T,
I-I Kmu? 7L? +'l et al., J, 0-y, .
0/'zm.

4'-diaminobenzophenone is produced by reducing 4'-dinitrobenzophenone by a method using a tin compound (T, May, eA2.r■□y+ et al. , J.A.
m, QhgS erc, 27) + 7 (1949)
).

However, 3,3'-dinitrobenzophenone and 3
, 4'-dinitrobenzophenone, it is extremely difficult to implement the above method industrially.

For example, 3,3'-dinitrobenzophenone can be produced by nitration of benzophenone.
The reaction product is a mixture containing isomers etc.
, 3'-dinitro form only requires the use of multiple solvents and repeated recrystallization purification:
C” (E, 11 o, vmn, t, t et al., J,
OL-m.

SαO,, 125767 (1924)). For this reason, 3
, 6'-dinitrobenzophenone decreases over a large period of time, and requires complicated steps such as recovery of the solvent used for binding and treatment of the residue.

In addition, recently, a method has been proposed to improve the quality of 21.Hush of benzophenone in a large amount of fuming sulfuric acid. There is a problem with waste acid treatment or a problem with the material of the equipment (A, On
n, pbLeyJ'ee et al., J, Oh3.0&m,,
46 5014 (1981)).

On the other hand, 3.4'-dinitrobenzophenone is 3.4-nitrobenzophenone than 4-nitrobenzyl alcohol and nitrobenzene.
A process for obtaining dinitrodiphenylmethane and then combining it with chromic acid to produce it (p, , r.

M-ag fat, 11ka, 49229'+~2294 (1
91S)), a method of obtaining phenylacetic acid and producing Jtp by captivating it with Chrome J-Tun (■, Mtyyy,
114 et al., J.A.m.

(,/um, Svo, ,su2635~2639(1
949)), a method for producing 4-nitrobenzophenone by nitration (V effect tn+, , , L, 13-a
J'-'et al., J, Ohg, Perkew, OL.
ml 2277 (1976)), etc. are known.

However, these methods have complicated reactions and
In addition, in order to remove a large amount of by-products such as isomers, it is necessary to repeatedly perform circular crystal purification. Therefore, dinitrobenzophenone is produced and then reduced to diaminobenzophenone (in order to implement the method industrially, it is necessary to carry out circular crystal purification repeatedly). It is clear that this is extremely disadvantageous economically.

The present inventors have made extensive studies on a method for producing 3,3'- or 6,4'-diaminobenzophenone that does not have the above drawbacks. As a result, we used a chlorodiaminobenzophenone compound represented by the general formula (r), which is already widely used industrially as a raw material for agricultural medicines and dye intermediates, as a raw material, touched it with palladium, and dredged it in the presence of soot. Alternatively, they found that the corresponding 6, 3'- or 2, 4'-diaminobenzophenones could be produced in high yields by reduction with formate and dechlorination, and the method of the present invention was completed.

That is, the method of the present invention is based on the general formula (1) (wherein, X represents a chlorine atom and is at the 4- or 6-position. In the case of , the amine group is at the 3'-position or the 4/-position.When Y is a chlorine atom at the 4'-position, the amino group is at the 3'-position). This is a method for producing 6,3'- or 4'-diaminobenzophenone, which is characterized by reducing the 6,3'- or 4'-diaminobenzophenone with formic acid or a formate salt and dechlorinating it.

The raw materials used in the method of the present invention are various chloro-substituted diaminobenzophenones represented by the general formula (1), and it is known that they can be produced by the reduction reaction of the corresponding dinitro compounds (for example, P, J , M
State Mugbe, Bzru, Su, 1027 (1q15
).

H, E, F=iiL et al. 1, ■, A771.0km, Se
C,, 77, 543 (1955), W. ayrl et al., lIJ'? , CIQm, Adn, 42.

1085 (1959), etc.).

Specifically, chloro-substituted diaminobenzophenone,
For example, 33'-diamino-4-chlorobenzophenone, 3'-diamino-6-chlorobenzophenone, 4'-diamino-4-chlorobenzophenone, 3.4
'-Diamino-6-chlorobenzophenone, ro, 3'-
Diamino-4,4'-dichlorobenzophenone, 3.3
'-Diamino-4,6'-dichlorobenzophenone is mentioned.

Although the palladium catalyst used in the method of the present invention can be used in a metallic state, it is usually used by being attached to the surface of a phase. Examples include palladium-activated carbon, palladium-alumina, palladium plaque, and the like. The amount of the catalyst used is in the range of 0.001 to 10% by weight based on the raw material chloro-substituted diaminobenzophenone.

The formic acid or formate salt used in the method of the invention is used as a water bath liquid. Further, the formate is an alkali formate salt such as sodium formate or potassium formate, and ammonium formate.

These formic acids or formic salts are used in a small excess of the theoretically required amount relative to the raw materials, but may be in the range of 1.5 to 10 times the amount.

This reaction usually uses a reaction solvent. The reaction solvent is not particularly limited as long as it is inert to the reaction, and a solvent miscible with water is usually used. For example, alcohols such as methanol, ethanol, and isopropyl alcohol, glycols such as ethylene glycol and propylene gellicol, ethers such as tetrahydrofuran, dioxane, and methyl cellosolve, and N,
N'-dimethylformamide, N-methylpyrrolidone,
Examples include aprotic polar solvents such as dimethylformamide.

The amount of solvent to be used is sufficient to suspend or properly dissolve the raw materials, and although there is no particular limitation, it is usually sufficient to use a solvent in an amount of 0.5 to 10% by weight relative to the raw materials.

The reaction temperature is not particularly limited, but is usually in the range of 30 to 110°C.

In carrying out the present invention, in general, raw materials are dissolved or suspended in a solvent, an aqueous solution of formic acid or a formate salt and a catalyst are added, and the reaction is then carried out with stirring at a predetermined temperature.

In either case, the reaction proceeded smoothly and the target product was 3.3'
- or 3,4'-diaminobenzophenone can be produced. Progress of the reaction can be monitored by thin layer chromatography and high performance liquid chromatography.

The reaction solution obtained by the above method is filtered hot to remove the catalyst, and then cooled or drained into water.
- or 6,4'-diaminobenzophenone is precipitated as crystals.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 0.3'-diamino-4,4'-dichlorobenzophenone 8.4,! 9 (0.03 mol), 07 g of 5tipalladium/activated carbon (Japan Engel Rud Co., Ltd.), 4 logs of 86 thiformic acid and 20 ml of N,N-dimethylformamide
was stirred at 50-60°C for 15 hours. Separate the catalyst, r
The liquid was drained into 50 ml of water to obtain a pale yellow precipitate of 3,5'-diaminobenzophenone. Yield: 54 g (yield: 85 g), melting point: 147-149°C.

Recrystallization from ethanol gave pure yellow needle crystals.

Melting point 150-151℃ Elemental analysis OT-IN Calculated value (%) 75.5 5,7 13.2 Measurement (Fi
t, (OA 73.9 5,9 15.6 Example 2 3.3'-diamino-4,6'-dichlorobenzophenone 8.4 g (0.3 mol), 5% palladium/alumina (Japan Engelhard) 0.4 g of sodium formate, 6.8 g of water, and 2 oml of methyl cellosolve! were stirred at 90 to 100°C for 8 hours. After cooling to 70°C, the catalyst was separated, and the r liquid was allowed to cool to room temperature. 3,3'
-Diaminobenzophenone was precipitated as yellow needle-like crystals. The crystals were separated, washed with water, and then dried. Yield 5.8j
q (yield: 91 cm), melting point: 148-150°C.

Example 3 3.3'~diamino-4-chlorobenzophenone 50j
;j (0.02 mol), palladium black 03g,
2.2.9 g of potassium formate, 1 g of water and 20 ml of ethylene glycol were stirred at 100-105°C for 6 hours.

After cooling to 80°C, the catalyst is separated.

After cooling the j''I solution to room temperature, 50 g of water was added to obtain yellow crystals of 6,3'-diaminobenzophenone. Yield: 37 g (yield: 87), melting point: 147-149°C.

Example 4 74 g of 4/-diamino-4-chlorobenzophenone
(0,03 mol), 5% palladium/activated carbon 0,5 l
, 2.2 g of 86% aqueous solution, 24 I of 28% ammonia water and 50 ml of ethanol at 55-60°C.
The mixture was stirred for 0 hours. If the catalyst is separated from P and cooled at the same temperature, 3
, 4'-diaminobenzophenone was precipitated as yellow crystals. Yield 58g (yield 91%), melting point 124-1255"
Recrystallization from C0 water gave pure pale yellow needle-like crystals of 1 (J). Melting point: 126-127°C.

Elemental analysis CII N t; -1≦1 ((IlIl order) 73.5' 5,7
13.2 measurement 1st shift (%) 73.8 5,4 13.0
Example 5 In Example 4, 3,4'-diamino-6-chlorobenzophenone was used and the other procedures were performed in exactly the same manner.
6,4'-diaminobenzophenone was obtained.

η rate: 90%.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd. 2 338

Claims (1)

[Claims] (In the formula, X represents a chlorine atom and is at the 4- or 6-position. Y represents a hydrogen atom or a chlorine atom, and when Y is a hydrogen atom, the amine group is at the 3'- or 4'-position. It is.Y
is a chlorine atom at the 4'-position, the amine group is at the 3'-position) is reduced with formic acid or a formate salt in the presence of a palladium catalyst to dechlorinate it. A method for producing 3,3'- or 4'-diaminobenzophenone.