JPS6150932B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing benzophenone derivatives. For more details, see the general formula () (In the formula, Ar represents an unsubstituted phenyl group, or a phenyl group substituted with a halogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, an alkoxy group having 1 to 4 carbon atoms, or a phenoxy group). 1,1-bis(aryl)-2,2,2-trichloroethanol is treated with an alkali. The present invention relates to a method for producing benzophenone derivatives. Generally, benzophenone derivatives are used in agricultural medicines, dye intermediates, etc., and halogenated derivatives in particular are useful compounds as raw materials for resins that exhibit excellent properties such as heat resistance, oxidation resistance, and light stability. Conventionally, methods for producing benzophenone derivatives include (1) a method in which an aromatic acid chloride and an aromatic hydrocarbon are subjected to a Friedel-Crafts reaction under a Lewis acid catalyst such as anhydrous aluminum chloride or anhydrous ferric chloride; (PH Gore, “Friedel Crafts
and Related Reactions” vol, p1, ed.byG.A.
Olah, John Wiley & Sons Inc. (1964)) is well known. In addition, (2) a method in which an aromatic hydrocarbon and carbon tetrachloride are reacted to form anhydrous aluminum chloride and then hydrolyzed (JPPircard et al. Can.J.
Research, 28B , 56 (1950)). (3) A method for producing 1,1-bis(4-halogenated phenyl)-2,2-dichloroethylene compound by chromic acid oxidation (HL Bradlow et al., J.Am.Chem.Soc., 69 , 662
(1947); O. Grumitt et al., J. Am. Chem. Soc., 67 ,
155 (1945); OG Backelerg et al., J.Chem.Soc.
1945 , 803) are known. However, among these methods, (1) requires an equimolar amount of anhydrous aluminum chloride to the aromatic acid chloride, and method (2) also requires an equimolar amount of anhydrous aluminum chloride to the aromatic hydrocarbon. Separation of aluminum chloride is complicated, cannot be reused, and requires equipment that is resistant to corrosion. In method (3), 1,1-bis(aryl)-2,2,2-trichloroethane is produced by the reaction of an aromatic hydrocarbon and chloral (for example, if aryl is a 4-chlorophenyl group, it is a DDT pesticide). ) as a raw material, it is relatively easy to make ethylene derivatives by treating it with an alkali (for example, O.Grumitt
et al., J. Am. Chem. Soc., 67, 155 (1945)), the use of large amounts of chromic acid in the oxidation reaction is extremely problematic and requires a great deal of expense, including waste liquid treatment. There are various difficulties that must be considered when implementing this on an industrial scale. As a result of intensive studies aimed at providing an industrially advantageous method for producing benzophenone derivatives, the present inventors discovered that 1,1-bis(aryl)
The present invention was achieved by discovering that benzophenone derivatives can be produced extremely easily by treating -2,2,2-trichloroethanol with an alkali. According to the method of the present invention, 1,1-bis(aryl)-2,2,2-trichloroethanol, which can be produced industrially at low cost, is used and treated with an alkali to produce benzophenone derivatives in high yield. This production method is industrially extremely advantageous since it causes no environmental problems compared to the conventional production of benzophenone derivatives using large amounts of aluminum chloride, chromic acid, etc. 1,1-bis(aryl)-2,2, of the general formula () used as a raw material in the method of the present invention
2-Trichloroethanol is obtained by chlorinating 1,1-bis(aryl)-2,2,2-trichloroethane obtained from aromatic hydrocarbons and chloral (e.g., O. Grumitt et al., J. Am. Chem. Soc. ,67,
155 (1945), W.Awe, Arch.Pharm., 283, 162
(1950); Chem.Abstr., 45, 583h (1953)), which can be easily produced by hydrolysis (for example, US Patent, Nos. 2812280 and 2812360).
issue). In the general formula (), the aryl group represents an unsubstituted or substituted phenyl group, and substituents for the substituted phenyl group include halogen, alkyl group, phenyl group, alkoxy group, phenoxy group, etc.
For example, phenyl, 4-fluorophenyl, 4-
Chlorophenyl, 4-bromophenyl, 4-iodophenyl, 4-methylphenyl, 4-ethylphenyl, 4-isopropylphenyl, 4-t-butylphenyl, 4-phenylphenyl, 4-methoxyphenyl, 4-ethoxyphenyl, 4-butoxy- Examples include phenyl and 4-phenoxyphenyl groups. According to the method of the invention, the reaction is carried out in aqueous solution or in an organic solvent. Examples of the alkali used include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, and alkali metal carbonates such as sodium carbonate and potassium carbonate. Alkali is generally used as an aqueous solution, but it may also be used after being dissolved in methanol, ethanol, or the like. The amount of alkali used is 1,1-bis(aryl)-2,2,2-
The amount is usually about 0.2 to 10 mol, preferably about 0.4 to 5 mol, based on trichloroethanol. Organic solvents used in the method of the present invention include hydrocarbons such as hexane, cyclohexane, benzene, toluene, and xylene, halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, and chlorobenzene, methanol, ethanol, isopropanol, Alcohols such as butanol, ethers such as diethyl ether, tetrahydrofuran, and dioxane, ketones such as acetone and methyl ethyl ketone, ethyl acetate, N.
Common organic solvents that are generally stable to alkalis, such as N-dimethylformamide and dimethyl sulfoxide, can be used. Further, there is no problem even if a mixture of these organic solvents is used, and a mixture with water is also used. In the method of the present invention, the reaction temperature is usually 0 to
It is in the range of 200°C, more preferably 10-150°C. When carrying out the reaction, 1,1-bis(aryl)-2,2,2-trichloroethanol is generally suspended or dissolved in water or an organic solvent, and an alkaline solution is added dropwise while maintaining the temperature at a predetermined temperature.
or 1,1-bis(aryl)-2,2,2-
A method of dropping a solution of trichloroethanol into an alkaline solution is also suitable, or there is no problem even if both are added at the same time in advance. If a precipitate precipitates out after a predetermined temperature and time, it is filtered as is, or if the product is dissolved in a solvent, it is discharged into water and then subjected to a usual post-treatment such as filtration to obtain the desired product. Note that as the reaction progresses, chloroform is generated. Chloroform can be expelled from the system during or after the reaction. Examples of benzophenone derivatives obtained by the method of the present invention include benzophenone, 4.
4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, 4,4'-diiodobenzophenone, 4.
4'-dimethylbenzophenone, 4,4'-diethylbenzophenone, 4,4'-diisopropylbenzophenone, 4,4'-di-t-butylbenzophenone, 4,4'-diphenylbenzo Phenon, 4.
Examples include 4'-dimethoxybenzophenone, 4,4'-diethoxybenzophenone, and 4,4'-diphenoxybenzophenone. Hereinafter, the present invention will be explained in more detail by giving examples. Example 1 1.1-bis(4-fluorophenyl)-2.
Dissolve 16.8 g (0.05 mol) of 2,2-trichloroethanol in 20 ml of methanol. 20% on this
5 g (0.025 mol) of an aqueous sodium hydroxide solution is added dropwise at room temperature. A precipitate immediately separates out, but the mixture is stirred at the same temperature for an additional hour. After filtering, washing with water and drying, 4,4'-difluorobenzophenone was obtained. Yield 10.5g (yield 96.5%), melting point 105-106
℃. Recrystallization from benzene yielded pure white plate-like crystals. Melting point 106-107℃. Examples 2 to 5 1,1-bis(phenyl)-2,2,2- instead of 1,1-bis(4-fluorophenyl)-2,2,2-trichloroethanol in Example 1
Trichlorethanol, 1,1-bis(4-methylphenyl)-2,2,2-trichlorethanol, 1,1-bis(4-methoxyphenyl)
-2.2.2-trichlorethanol, 1.1
-bis(4-bromophenyl)-2,2,2-trichloroethanol or 1,1-bis(4-
A reaction was carried out in the same manner as in Example 1 using chlorophenyl)-2,2,2-trichloroethanol and the alkali shown in Table 1 to obtain a benzophenone derivative. The results are shown in Table-1.

[Table] Example 7 1.1-bis(4-chlorophenyl)-1.
38.9 g (0.1 mol) of 2,2,2-tetrachloroethane, 4 ml of water, 4 g of 96% sulfuric acid and 78 ml of glacial acetic acid were heated under reflux (115-121°C) for 30 hours. After distilling off glacial acetic acid under reduced pressure, add 50ml of water and heat to 80-90℃.
40% sodium hydroxide solution while keeping the temperature at
Add 30 g (0.3 mol) over about 10 minutes. Stir for another 1 hour at the same temperature. During this time, the chloroform that azeotropically distills off with water is separated in a separator.
After cooling to room temperature, filter, wash with water, and dry.
4'-dichlorobenzophenone was obtained. Yield 23.2g
(yield 93%), melting point 144-145°C. Recrystallization from methanol yielded pure white scaly crystals. Melting point 146-147℃.

Claims (1)

[Claims] 1 General formula () (In the formula, Ar represents an unsubstituted phenyl group, or a phenyl group substituted with a halogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group, an alkoxy group having 1 to 4 carbon atoms, or a phenoxy group). A method for producing a benzophenone derivative, which comprises treating 1,1-bis(aryl)-2,2,2-trichloroethanol with an alkali.