SU654603A1 - Method of obtaining benzophenone derivatives - Google Patents

Description

This invention relates to a method for producing benzophenone derivatives, more precisely symmetric p, p-substituted benzophenones, which are widely used in the synthesis of starting compounds for heat-resistant polymers. iron 1. This method allows to obtain 2,4- and 4,4-disubstituted benzophenones in a 1: 9 ratio, respectively. The use of specific solvents allows the isolation of almost one target symmetric isomer with a yield of 68-72 mol%. The disadvantages of this method are the use of a catalyst, the presence of a side asymmetric measure, and the insufficiently high yield of the target 4,4-disubstituted benzophenones at 180-250 ° C. BEPCODE of target products does not exceed 80% 2. However, with this method, significant amounts of side 2,4-substituted benzophenone are formed, which reduces the yield of the target product and complicates its preparation due to the difficulty of isolation. In order to simplify the process and increase the yield of the target products, it is proposed to use a method of obtaining benzophenone derivatives of the general formula where R, R-CI, CH3ILY NO, by reacting the benzene derivative of the general formula where R has the above value, with the benzoyl chloride derivative of the general formula - / (L -COC1, where R has the aforementioned 3a. value, at elevated temperature, a distinctive feature of which is that the process is carried out at a temperature of 260280 ° C.

The proposed method improves the selectivity of the process (up to 99.7%) and simplifies the allocation of the celery product in a yield of up to 90%.

Example 1. A stainless steel autoclave purged with an inert gas was charged with 77.25 g (0.5 mol) of p-toluic acid chloride and 69 g (0.75 mol) of topuol, heated to 260 ° C and reacted for 2 hours. After cooling the abtoclave, the excreted hydrogen chloride is vented and the reaction mass is transferred to a distillation flask for distillation. Excess toluene was distilled off at atmospheric pressure, and 97.8 g of the desired product was isolated by vacuum distillation (178/5 mm Hg). 84.1 g were obtained by crystallization from isopropyl alcohol ( yield 90.2 mol.%) 4,4-dimethylbenzophenone with so pl. 95.5- 96 ,.

Found,%: C 05.59; H 6.72;

Cxg-N..O

Calculated,%: C 85.70; P 6.67.

Example 2. A stainless steel autoclave, purged with an inert gas, was charged with 17.5 g (0.1. Mol) of p-chlorobenzoic acid chloride and 34.5 g (0.3 mol) of chlorobenzene.

The autoclave is heated to 270 ° C and the reaction is carried out for 1.5 hours. The expected product is isolated in Example 1. 23.1 g of the desired product is isolated by vacuum distillation (174 ° C) (5 mm Hg). 92.03 mol%). Crystallization from propyl alcohol gives 18.72 g of colorless plates (output 80.95 mol.%) Of 4,4-dichlorobenzophenone with mp. l47-i48C.

Found,%: C 62.37; H 3.24; se

Calculated,%: C 62.15; H 3.19; Se 28,29.

Example 3. A stainless steel autoclave, purged with an inert gas, was charged with 16.7 g (0.1 mol) of p-chlorobenzoic acid chloride and 27.6 g (0.3 mol) of toluene, heated to 260 ° C and reaction for 2 hours. The product of example 1 is isolated. Vacuum distillation (mm Hg) gives 21.4 g (yield 92.84 mol%) of the desired product. Crystallization from propyl alcohol gives 19.8 g (yield 92.5 mol%) of 4-chloro-4-methylbenzophenone with mp. 129-130 ° C.

Found,%: C, 72.96; 4.71; This is 15.54.

 seo

Calculated,%: C, 72.89; H 4.77; every 15.40.

Pr, imer .4. 15.45 g (0.1 mol) of p-toluic acid chloride and 33.75 g (0.3 mol) of chlorobenzene are loaded into a stainless steel autoclave, purged with argon (or nitrogen), and heated to 270 seconds for 2 hours. The product of example 1 was isolated. Vacuum distillation (164 ° C / 3 mmHg) isolated 21.5 g (yield 92.9 mol.%) Of the desired product. By crystallization from propyl alcohol, 19.5 g were obtained (yield 90.7 mol.%) 4-chloro-4-methylbenzophenone with mp 129.5-13 O C.

Example 5. 18.75 g (0.1 mol) of p-nitrobenzoyl chloride and 27.6 g (0.3 mol) of toluene are charged into a stainless steel autoclave / purged with an inert gas. The reaction mass is heated to 260 ° C for 1.0 h. The product of example 1 is isolated. Vacuum distillation 22.7 g (yield 94.2 mol%) of the desired product is isolated by crystallization of which from benzene gives 20.1 g (yield 88.6 mol.%) 4-nitro-4-methyLbenzophenone with mp 1234C, (bp 161-163s at 5 mm Hg).

Found,%: C 69.83; H 4.61; N 5.72.

 H oz N

Calculated,%: C 69.71; H 4.56; N5.21.

Example 6. 37.5 g (0.2 mol) of p-nitrobenzoyl chloride and 67.5 g (0.6 mol) of chlorobenzene are loaded into a stainless steel autoclave purged with an inert gas, and heated to 265-270 s for 1.0 h. The product is isolated from the reaction mass according to example 1..

Get 49,3 g (yield 95,4 mol.%) Of the target product, the crystallization of which from benzene receive. 44.8 g (yield 90.9 mol.%) 4-nitro-4-chloro benzophenone with so pl. 99-UO S (bp. 24G ° C at 12 mm Hg).

Found,%: C 54.90; H 3.14; N 5.42; every 13.71.

Calculated,%: C 59.66; H 3.06; N 5.35; every 13,58.

Analogously to example 1, examples 7-34 are carried out. Conditions and results are presented in the table. Examples 7,8,10,14,15,17,19,21,22, 27,29,30,32 and 33 are given for comparison.

Claims (1)

 - Conversion in 2 hours. Formula of inventive benSephod of obtaining zofenone derivatives of general formula where R, R-CI, CH3, OR NO by interaction of pr9Isurna1O b, enzol of general formula 65460 10 8 where K has the above value, at elevated temperatures, about the fact that, in order to simplify the process and keep the yield of the target product, the process is carried out at 260-280 ° C. Sources of information taken into account during the examination 1. USSR author's certificate No. 385961, C 07 C 49/7 6, 1971, 2, Sachaman A.W., Caesar P.D., Ind. And Eng. Chem., 1946, p.38, p, 43 ANGP.p. No. 139453, c.