DE1139111B - Process for the preparation of diaryl ketones. - Google Patents

Description

GERMAN

PATENT OFFICE

R 25995 IVb / 12 ο

REGISTRATION DATE: JULY 20, 1959

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL: NOVEMBER 8, 1962

The invention relates to a process for the preparation of diaryl ketones in general formula

W. ζ -c- W. ζ Λ Il Λ j ο ί

In the formula, W, X, Y and Z denote hydrogen, methyl, ethyl, isopropyl, tert-alkyl radicals with 4 to 12 carbon atoms, chlorine, bromine, n-alkoxyl radicals with 1 to 21 carbon atoms, a phenoxyl group or phenoxy radicals, which are represented by 1 to 5 ortho- or para-pointing groups are substituted, with the proviso that n-alkoxyl, phenoxyl or substituted Phenoxy groups, chlorine or bromine atoms are only present if two to three of the radicals W, X, Y and Z represent hydrogen. However, the four radicals W, X, Y and Z do not designate simultaneously Hydrogen.

According to the invention, diaryl ketones of this type are prepared by adding 2 equivalents of an aromatic Compound of the general formula

with 1 equivalent of a 2,6-substituted benzoic acid of the general formula

R ₄ R2

in the temperature range from about 25 to 235 ° C in the presence of a carboxyl group eliminating Catalyst acidic character converts until the carboxylic acid of the reaction mixture of their Carboxyl group is freed.

The substituents Ri to Rs have the following Meaning: Ri and R2 represent individually methyl, Ethyl or isopropyl groups, R3, R4, Rs either hydrogen, methyl, ethyl, an n-alkoxyl group Process for the preparation of diaryl ketones

Applicant:

Rohm & Haas Company, Philadelphia, Pa. (V. St. A.)

Representative: Dr.-Ing. Dr. jur. H. Mediger, patent attorney, Munich 9, Aggensteinstrasse

Claimed priority: V. St. v. America from June 29, 1958 (No. 751 615)

Reynold Clayton Fuson, Urbana, 111., and Bruno Martino Vittimberga,

Jenkintown, Pa. (V. St. A.) have been named as inventors

with 1 to 21 carbon atoms, a phenoxy group or a phenoxy group, which is represented by 1 to 5 ortho- and para-pointing groups, with the proviso that if R3 and R4 are substituted by hydrogen are occupied, R5 additionally represents an alkyl radical having 3 to 12 carbon atoms and at least one the pairs R3-R5 and R4-R5 together form an oxygen bridge the general formula

- O - (CH ₂ ) _ra -O

denotes, where η is an integer from 1 to 10, and at least one of the pairs R1-R3 and R2-R4 denotes common bridges with 3 to 13 carbon atoms, which can optionally be interrupted by 1 to 2 oxygen, sulfur or nitrogen atoms , with the restriction that there are at least 2 carbon atoms between 2 of the additional heteroatoms mentioned, and the further restriction that the number of carbon atoms of two bridge members together is at least 7.

Preferably the locations are Ri and R2, respectively occupied by the same groups within the given definition. R3, R4 and R5 can be used with be occupied by the same or different substituents. In addition to the specified alkyl radicals, as typical substituents for the radicals R3 to Rs

209 680/337

named: Methoxyl, Propoxyl, Butoxyl, Octoxyl, Decoxyl, Dodecoxyl, tetradecoxyl, octadecoxyl, eicosoxyl, heneicosoxyl, phenoxyl, p-chlorophenoxyl, p-methocyphenoxyl, m-nitrophenoxyl, p-methylphenoxyl.

When R3 and R4 are occupied by hydrogen atoms are, R5 can also with alkyl groups with 3 to

12 carbon atoms of any structural configuration, but preferably branched chain Groups such as isopropyl, tert-butyl, hexyl, octyl, nonyl, tert-decyl, undecyl and tert-dodecyl are occupied. Furthermore, as already mentioned, the pairs R3-R5 or R4-R5 can jointly form a bridge formula

- O - (CH ₂ ) "—O—

represent, where η is preferably 1 or 2. In addition, the pairs R1-R3 or R2-R4 or both of these pairs can be bridges with 3 to

Represent 13 carbon atoms. If both pairs form such bridges at the same time, then the The total number of carbon atoms in both bridges should be at least 7. As bridges in the sense of The present invention applies to both straight carbon chains and chains with alkyl substituents. in the in general and preferably these bridges are purely hydrocarbon in character. But you can also be interrupted by 1 or 2 oxygen, sulfur and nitrogen atoms, which are either in Ether, thioether, amino or an alkyl group with 1 to 21 carbon atoms, such as methyl, Ethyl, butyl, octyl, dodecyl. Octadecyl or Eikosyl, substituted amino groups are present, with the Restriction that at least 2 carbon atoms between 2 of the mentioned heteroatoms present stand, and the further restriction that the number of carbon atoms of two bridge members together is at least 7.

In general, bridges of carbon character are preferable, such as tetramethylene, hexamethylene, Octamethylene, dodecamethylene or tridecamethylene. When a bridge through a tetramethylene group is shown, then, as stated above, if another bridge is available, the other being at least trimethylene. Within the stated numbers of carbon atoms these bridges can also contain alkyl substituents, e.g. B. 1,1,4,4-tetramethyltetramethylene or 1 -methyl trimethylene.

azaanthracene-9-carboxylic acid, 1,2,3,4,5,6,7,8-octahydro - 2,7 - dimethyl - 2,7 - diazaanthracene - 9 - carboxylic acid, 1,2,3,4,5,6,7,8 - octahydro -1 - azaanthracene-10 - carboxylic acid, 2,3,4,5,6,7,8 - heptahydro -1 - oxaanthracene -10 - carboxylic acid, 1,3,4,5,7,8,9,10 - octahydro-naphth- [2,3-c] - [2,5] -oxaazepine-11-carboxylic acid, 2,3,4,5,6,7,8-heptahydro-1-thiaanthracene-10-carboxylic acid, 1, SAS.o ^ S-heptahydro ^ -oxa ^ -azaanthracene-9-carboxylic acid, 2,3,4,5,6,7,8-heptahydro-1-oxa-6-azaanthracene-10-carboxylic acid, 5,6,7,8-tetrahydrobenz- [f] -isoindoline-9-carboxylic acid, 1,3,5,6,7,8-tetrahydrobenz- [f] -isothianaphthene-9-carboxylic acid, 2,7-Dihl ^ A ^ hdh ^ b

acid, 2-methyl-1,2,3,4,5,6,7,8-octahydroanthracene-9-carboxylic acid.

Typical representatives of the reactant of the formula

are for example benzene, 1,2,3,4-tetramethylbenzene, m-xylene, o-xylene, 1,2,3-trimethylbenzene, 1,3,4-trimethylbenzene, Toluene, anisole, 1,2-dimethoxybenzene, octadecylphenyl ether, 2,4-di-tert.-butylbenzene, 1-methyl-3-tert.-dodeeylbenzene, 1,2-dichlorobenzene, 1,3-diehlobenzene, l-bromo-3-chlorobenzene, chlorobenzene, bromobenzene, diphenyl ether.

The general temperature range of the reaction is from 25 to 235 ^° C., preferably from 50 to 200 ^° C., with the proviso that the temperature at which the carboxylic acid present as a reactant loses its carboxyl group must be selected within these ranges. This temperature can be determined so that the carboxylic acid reactant, once freed from its carboxyl group, can generally be isolated or removed from the reaction mixture by known methods and in many cases can be recognized by its volatility or sublimation. The reaction is carried out until the carboxyl group is practically completely eliminated from the reactant carrying it. At this point in time the reaction has ended with the highest yields. The person skilled in the art is readily able to carry out this reaction in the individual case

Typical representatives of the 2,6-disubstituted benzoin 50 required temperature to be set.

acid reactants are:

2,6-dimethylbenzoic acid, 2-ethyl-6-methy_lbenzoic acid, 2,3,5,6-tetramethylbenzoic acid, 3-ethyl-2,5,6 - trimethylbenzoic acid, 2,3,4,5,6 - pentamethylbenzoic acid, 4-ethyl-2,3,5,6-tetramethylbenzoic acid, 4-bromo-2,3,5,6-tetramethylbenzoic acid, 4-methoxy-2,3,5,6-tetramethylbenzoic acid, 4-phenoxy-2,3,5,6-tetramethylbenzoic acid, 4-isopropyl - 2,6 - dimethylbenzoic acid, 4-tert-butyl-2,6-dimethylbenzoic acid, 4 - (α, α - dimethyl) - decyl - 2,6 - dimethylbenzoic acid, 2,6-dimethyl-3,4-methylenedioxybenzoic acid, 2,6-dimethyl-3,4-hexamethylenedioxybenzoic acid, 1,2,3,4, S ^ J ^ -Octahydroanthracen ^ -carboxylic acid ^^ - Hexa-Preferably the aromatic hydrocarbon is used in excess. To the successful Carrying out the reaction must have 2 molar equivalents of the aromatic hydrocarbon with 1 molar equivalent of the reactant containing the carboxyl group are reacted. In interest For the highest yields of diaryl ketones, it is advisable to use an excess of the aromatic hydrocarbon to use beyond this molar ratio.

It is possible to have 1 equivalent of two different aromatic hydrocarbons with 1 equivalent of the reaction bearing the carboxyl group

methylene-5,6-hexamethylene benzoic acid, 1,2,3,4,5,6, apply to a mixture of three

7,8-octahydro-2-azaanthracene-9-carboxylic acid, 1,2,3, 65 products, namely one symmetrical and two

4,5,6,7,8-octahydro-2-methyl-2-azaanthracene-9-car unsymmetrical to form. In the interest of the

bonsäure, 3,4,5,6,7,8-hexahydro-2- [1H] -oxaanthra reduction of problems of the separation of the reac-

cen-9-carboxylic acid, 1,2,3,4,5,6,7,8-octahydro-2,7-dionic products but it is preferable to use 2 moles of one

5 6

single aromatic hydrocarbon of the react. The method of the invention offers an un-

application participant. In general, the indirect method for the production of the ketones in

the reaction at atmospheric pressure is more effective, convenient, and easily controllable

guided. Working with negative pressure is, however, avoiding corrosive, toxic or possible if for some reason it is difficult to handle for other reasons

is desired or seems appropriate. Respondents. Its advantage also lies in

To carry out the process of the invention that it is the diaryl ketones with one reaction step

suitable catalysts, which in the process produces which by known processes only about

conditions the elimination of the carboxyl group three or more reaction stages can be obtained cause are phosphorus pentoxide, especially 85pro- io. The process products are suitable as

phosphoric acid, mixtures of both, especially known as insecticides and fungicides,

those referred to as polyphosphoric acid illustrate the examples below

and Lewis acids such as zinc chloride, ferric embodiments of the invention. The parts are

chloride, mercuric chloride, stannous chloride, aluminum parts by weight. The yields refer to the chloride, boron trifluoride and etherates and complexes 15 aromatic carboxylic acid used in each case, of boron trifluoride (U.S. Patents 2,400,873,

2 393 608, 2 393 609, 2 393 610, 2 393 611, 2 394583). Example 1 It should be noted that aluminum chloride within

the specified temperature range with gentle production of di-p-anisyl ketone the temperatures should be applied so that it 20

does not bring about undesired isomerizations. λ - ^ , - ^

The preferred catalysts are phosphorus pent- _{CH 3} O- ^ p- CO- <f j> -OCH3

oxide, phosphoric acid and combinations of both, v = / \ = / especially the so-called polyphosphoric acid.

These catalysts lead to higher yields. 25 In a 200 ccm three-necked flask equipped with a stirrer,

and shorter response times. Cooler and stopper is fitted, one pours

In some cases, especially if the kata- 35 parts warm polyphosphoric acid, 2 parts coarse

lysator and the reactants are solids, ground duronic acid and 35 parts anisole, stirs

the presence of a solvent can form the mixture vigorously for 1 hour while using

an inert, volatile, but relatively high 30 of a sand bath, the temperature of 8O ⁰ C increases,

boiling organic liquid be appropriate. and then keeps the temperature at 8O ⁰ C for 4 hours.

But if the catalyst is like polyphosphoric acid, then you raise the temperature of the mixture

or at least one of the reactants is liquid at 160 ^° C. with the flask open and holds it

one prefers to work without solvents. If upright for 7 hours. You then pour the hot one

the aromatic reaction mixture participating in the reaction in 100 parts of distilled water,

Hydrocarbon is a liquid, then the aqueous-organic mixture can be extracted four times

an additional amount of this participant's function with ether, washes the ethereal solution three times with one

of a solvent. Appears in an aqueous, 5% solution of sodium bicarbonate

In some cases a solvent is necessary or twice with distilled water, it over-dries

If so, they are saturated aliphatic hydrocarbons and sodium sulphate. The filtered one is concentrated

Hydrogen, such as hexane, decahydronaphthalene or an ethereal solution in a water jet vacuum.

high molecular weight aliphatic ethers, such as dipentyl, dries in a high vacuum for 5 minutes and is retained

ether, dihexyl ether, applicable. They look like orange crystals. The recrystallization from

Termination of the reaction in a known manner, e.g. B. Ethanol gives 1.35 parts of orange flakes

by distillation under reduced pressure, having a melting point of 140 to 143 ° C (according to literature

distant. Di-p-anisyl ketone melts at 143 to 144 ⁰ C). The end-

After completion of the reaction, the spoil formed can 50% of the theory that by narrowing the

Diaryl ketone obtained by known methods mother liquor can be brought to 55 to 60%.

Example 2

Production of 4,4'-di- (p-phenoxylbenzoyl) -

diphenyl ether £

100 parts of the distilled reaction mixture are poured into a three-necked reflux reaction mixture with a glass stopper

cooler and stirrer equipped 200 ccm bottle of water, rinses the bottle with water, extracts the

one brings 35 parts warm polyphosphoric acid, sets 60 aqueous-organic mixture with ether, washes the

2 parts of coarsely ground 4-phenoxy-2,3,5,6-tetramethyl ethereal solution several times with aqueous 5%

benzoic acid and 10 parts of diphenyl ether, stir sodium bicarbonate solution and twice with water,

For 1 hour while the temperature is used to dry the extract over anhydrous sodium

a sand bath is brought to 8O ⁰ C. The sulfate is kept, the desiccant is filtered off and it is evaporated

this temperature maintained for 4 hours, increased 6 ₅ solvent at 35 ⁰ C and obtained the expected

it then to 160 ⁰ C and keeps it for 7 hours on product F. = 208 to 212 ° C, the chromatographically

this height, while the excess diphenyl is cleaned on aluminum oxide (alumina). the

ether is removed under vacuum. The hot yield is 38%.

Example 3 Preparation of 4,4'-dichlorobenzophenone

Place in a three-necked bottle equipped with a glass stopper, condenser and mechanical stirrer 35 parts of polyphosphoric acid, sets 35 parts of chlorobenzene and 3 parts of 1,2,3,4,5, xo with vigorous stirring oJ ^ -Oetahydroanthracen ^ -carboxylic acid to, heated the mixture within 2 hours by means of a sand bath up to 160 ° C, maintains this temperature Continue upright for 30 minutes, then open the bottle, increases the temperature to 170 ° C within 30 minutes and keeps it there for another 4 hours Height. Working up as in Example 2. The 4,4-dichlorobenzophenone obtained is recrystallized Purified from ethanol. F. = 145 to 147 ° C. The yield is 35%.

Example 4

Production of 2,4,2 ', 4'-tetra-tert-butylbenzophenone

C (CHa) ₃ C (CHs) ₃

(CHs) ₃ C

C (CHs) ₃

40 parts of polyphosphoric acid are placed in a three-necked bottle equipped with a glass stopper, reflux condenser and mechanical stirrer, 2 parts of 2,3,4,5,6,7,8-heptahydro-1-thiaanthracene-10-carboxylic acid and 10 parts of 2,4 are added -di-tert-butylbenzene to, presents to the stirrer, the mixture is heated over one hour to 80 ° C, this temperature is maintained for 4 hours upright, open the vessel, the temperature raised to 160 ⁰ C and keeps it for 4 hours for Height. The hot reaction mixture is then poured into 100 parts of distilled water and the bottle is rinsed with water. The aqueous-organic mixture is extracted twice with ether and twice with chloroform, the extract is dried over anhydrous sodium sulfate and, as in Example 1, the stated reaction product, boiling point 5172 to 175 ° C., is obtained in 37% yield.

_{Under the same reaction conditions, 2,4 5} 2 ', 4'-tetramethylbenzophenone is obtained from m-xylene and duronic acid in 44% yield as an orange

red oil with
Bp 10 190 ° C.

the refractive index nf = 1.5853,

Example 5

Production of 2,3,4,5, 2 ', 3', 4 ', 5'-octamethyl-

benzophenone

CH ₃ CH ₃

CH ₃ CH ₃

CH ₃

CH ₃

CH ₃
In the example 1

CH ₃

p device described one brings 35 parts warm polyphosphoric acid, sets Parts of 2,6-dimethyl-3,4-methylenedioxybenzoic acid and 35 parts of 1,2,3,4-tetramethylbenzene, stir and If the mixture is heated to 80 ° C. within an hour by means of a sand bath, this temperature is maintained 4 hours upright, then heated to 160 ° C and maintains this temperature for 4 hours, removes the excess 1,2,3,4-tetramethylbenzene 160 ° C in a vacuum. The reaction mixture is worked up as in Example 1 and the information given is obtained Product in 47% yield, which is purified by recrystallization from ethanol. Analysis of the product:

Found C 84.2% (theoretical 85.7%), found H 8.5% (theoretical 8.8%).

Example 6

Production of 2,2'-dimethyl-4,4'-di-tert-dodecylbenzophenone

CH ₃

(Ci ₂ H ₂₅ ) SC

C (C ₁₂ H ₂₅ ) S

In the device used in Example 1, 40 parts of polyphosphoric acid, 2 parts of 1-methyl-3-tert-dodecylbenzene and 10 parts of 1,2,3,4,5,6,7,8-octahydro ^ -azaanthracene ^ - carboxylic acid. The mixture is stirred rapidly while the temperature was raised within one hour to 8O ⁰ C. and held 4 hours constant, it further heated to 160 ⁰ C and kept at this temperature 4 hours upright. After working up the hot reaction mixture as in Example 1, the desired product is obtained in 43% yield, which is purified by recrystallization from chloroform-ethanol.

Analysis of the product:
Found C 84.1% (theoretical 85.9%), found H 10.9% (theoretical 11.4%).

Claims (2)

PATENT CLAIMS: 1. Process for the preparation of diaryl ketones of the general formula W W characterized * that in the presence of a carboxyl group-removing catalyst acidic character in the temperature range from 25 to 235 ° C 2 mol of a compound of the general formula with 1 mole of a compound of the general formula COOH R ₄ R2 until the carboxyl group of the latter is completely eliminated, with W, X, Y, Z water substance, methyl, ethyl, isopropyl, tert-alkyl groups with 4 to 12 carbon atoms, chlorine, bromine, n-alkoxyl groups with 1 to 21 carbon atoms, Phenoxyl or phenoxy radicals substituted by 1 to 5 ortho- and para-pointing groups are, with the proviso that the substituents are n-alkoxyl, phenoxyl, substituted Phenoxyl, chlorine and bromine can only occur if two or three of the radicals W, X, Y, Z are occupied by hydrogen, while Ri and R2 individually methyl, ethyl, isopropyl, R3, R4, Rs individually hydrogen, methyl, ethyl, an n-alkoxyl group having 1 to 21 carbon atoms, the phenoxy group, optionally substituted by 1 to 5 is substituted ortho- and para-pointing, with the proviso that, if R3 and R4 are occupied with hydrogen atoms, R5 additionally an alkyl group with 3 to 12 carbon atoms means and at least one of the pairs R3-R5 and R4-R5 together form an oxygen bridge general formula - O - (CH ₂ ) _re —O -
- η is an integer from 1 to 10 - and min- 10 at least one of the pairs R1-R3 and R2-R4 together represent bridges with 3 to 13 carbon atoms, which optionally interrupted by 1 to 2 atoms of oxygen, sulfur or nitrogen atoms may be, with the restriction that at least 2 carbon atoms between 2 of the mentioned additional heteroatoms, and the further restriction that the number the carbon atoms of two bridge members together are at least 7, but in in each case at least one of the substituents W, X, Y, Z does not represent a hydrogen atom. 2. The method according to claim 1, characterized in that the catalyst used is phosphorus pentoxide, at least 85% phosphoric acid, polyphosphoric acid, zinc chloride, ferric chloride, mercury chloride, Tin (IV) chloride, aluminum chloride, boron trifluoride and etherates and complexes thereof be used. Considered publications:
German Patent Nos. 621454, 934 525;
U.S. Patent Nos. 1936 091, 2,386,007,
645 663, 2 818 436.