DE10152789A1 - Production of polyhalogenated cinnamic acid derivatives useful as intermediates in producing indanone derivatives, involves reacting diazonium salt with acrylic acid compound in presence of palladium catalyst - Google Patents

Abstract

Production of polyhalogenated cinnamic acid derivatives (I) involves reacting a diazonium salt (II) with an acrylic acid compound (III) in the presence of a homogeneous palladium catalyst at -5 to +100 deg C. Production of polyhalogenated cinnamic acid derivatives of formula (I) involves reacting a diazonium salt of formula (II) with an acrylic acid compound of formula (III) in the presence of a homogeneous palladium catalyst at -5 to +100 deg C. R<1>-R<4> = H, F, Cl or Br, at least two being other than H; X = OR<5> or NR<6>R<7>; R<5> = H, optionally substituted 1-10C alkyl, optionally substituted phenyl or benzyl; R<6>, R<7> = optionally substituted 1-10C alkyl; R<8> = H, Cl, Br or optionally substituted 1-10C alkyl; A<-> = halide, bisulfate, nitrate, acetate, tetrafluoroborate, sulfate or phosphate. Independent claims are also included for the following: (1) Process for preparing indanone derivatives of formula (IVa), involves hydrogenating compound (I) and cyclizing the product; and (2) Process for preparing indanone derivatives of formula (IVb), involves preparing a compound (IVa) as in (1), halogenating the product if R<8> is hydrogen, and subjecting the product to palladium-catalyzed carbonylation with carbon monoxide and a nucleophile. R<9> = COOH, CONH2 or COOR<10>; and R<10> = 1-4C alkyl.

Description

The present invention relates to new polyhalo-substituted cinnamic acids and Cinnamic acid derivatives and a process for the production of known and new polyhalo-substituted cinnamic acids and cinnamic acid derivatives.

Known halogen-substituted cinnamic acids and cinnamic acid derivatives are Intermediates for the production of agrochemicals and pharmaceuticals (see DE-A 22 44 761, WO 95/30645, WO 94/26692, WO 94/7893, WO 94/26693 and US-A 5 753 655).

2,4-difluorocinnamic acid and its esters of formula (II) can be prepared by Benzyl halides of the formula (I) with acetic anhydride or benzaldehydes of the formula (I) reacted with malonic acid or malonic acid esters.

The following reaction equation illustrates this:

The disadvantage here is the high reaction temperature required, the unsatisfactory one Yield and the difficult accessibility of the compounds of formula (I). In Monthly journal of Chemistry 90, 680 (1959) is the implementation of 2,4-difluorobenzaldehyde with acetic anhydride at 180 ° C, wherein 2,4-difluorocinnamic acid in 77% yield is obtained.

Another way to make a halogen substituted Cinnamic acid derivative is based on 2,4-difluorobromobenzene and this with acrylic acid Addition of triphenylphosphine palladium dichloride and potassium carbonate in Dimethylformamide reacted at 145 to 150 ° C in the course of 6 hours. The corresponding cinnamic acid derivative is obtained in a yield of only 54% (Russ. J. Org. Chem. 33 (4), 563-569 (1997)). Here the yield is even more unsatisfactory and it high reaction temperatures and long reaction times are also required.

Finally, it is known from EP-A-584 043 that compounds of the type Ar-CHR _a -CHR _b R _c can be prepared if diazonium salts of the type AR-N ₂ ^{⊕ are used} with compounds of the type CR _a = CR _b R _c reacted to form compounds of the type Ar-CHR _a = CR _b R _c and works in the presence of homogeneous palladium catalysts and with the addition of 1 to 10 equivalent bases. This process is particularly suitable for the preparation of compounds in which the Ar radical is substituted by a sulfonic acid group, that is to say a strongly polar group. In addition to this restriction, it is disadvantageous that large amounts of bases have to be added in this process, which means additional costs and requires a complex workup of the reaction mixture.

EP-A-584 264 describes a method similar to EP-A-584 043. It is however worked in the additional presence of arylphosphines, what with further costs and additional effort is connected.

There is therefore still a need for a method for producing polyhalogenated cinnamic acids and cinnamic acid derivatives, in which in a simple manner moderate temperatures, with short reaction times, without base addition and without mandatory addition of arylphosphines the desired products in higher Yield than previously available.

A process has now been found for the preparation of polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula (III)


in the
R ¹ , R ² , R ³ and R ^{4 are the} same or different and each represents hydrogen, fluorine, chlorine or bromine, at least two of these radicals being different from hydrogen and
X represents OR ⁵ or N (R ⁶ ) (R ⁷ ), where
R ^{5 represents} hydrogen, optionally substituted C ₁ -C ₁₀ alkyl, optionally substituted phenyl or benzyl and
R ⁶ and R ^{7 are the} same or different and each represents optionally substituted C ₁ -C ₁₀ alkyl and
R ^{8 represents} hydrogen, chlorine, bromine or optionally substituted C ₁ -C ₁₀ alkyl,
which is characterized in that a diazonium salt of the formula (IV)


in the
R ¹ , R ² , R ³ and R ^{4 have} the meaning given for formula (III) and
A ^{⊖ stands} for one equivalent of halide, hydrogen sulfate, nitrate, acetate or tetrafluoroborate ions or for S equivalent of sulfate ions or for 1/3 equivalent of phosphate ions,
with acrylic acid or an acrylic acid derivative of the formula (V)


in the
X has the meaning given for formula (III) and
R ^{8 represents} hydrogen, chlorine, bromine or optionally substituted C ₁ -C ₁₀ alkyl,
in the presence of a homogeneous, palladium-containing catalyst at -5 to + 100 ° C.

The method according to the invention is advantageous and without base addition carried out without the addition of arylphosphines.

Insofar as the radicals R ⁵ , R ⁶ , R ⁷ and R ⁸ are optionally substituted alkyl radicals, substituents such as. B. halogen, hydroxy or C ₆ -C ₁₂ aryl radicals come into question. Of these substituents, e.g. B. per residue from the group R ⁵ , R ⁶ , R ⁷ and R ⁸ 1 to 2 may be present.

R ^{1 is} preferably hydrogen or chlorine, R ^{2 is} hydrogen, fluorine, chlorine or bromine, R ^{3 is} hydrogen or chlorine and R ^{4 is} fluorine or chlorine, at least one of the radicals R ¹ , R ² and R ^{3 being} different from hydrogen is.

R ⁵ preferably represents hydrogen, methyl, ethyl, isopropyl or benzyl. R ⁶ and R ⁷ are preferably methyl or ethyl. R ⁸ preferably represents hydrogen or methyl. A ^⊖ is preferably one equivalent of chloride, hydrogen sulfate or acetate or 1/2 equivalent of sulfate.

As homogeneous, palladium-containing catalysts such. B. Palladium (II) and palladium (O) compounds in question such as PdCl ₂ , PdBr ₂ , Pd (NO ₃ ) ₂ , H ₂ PdCl ₄ , Pd (CH ₃ COO) ₂ , Na ₂ PdCl ₄ , K ₂ PdCl ₄ , Pd (II) acetylacetonate, tetra (triphenylphosphine) Pd and tris (dibenzylidene acetone) Pd _{2 are possible} . PdCl ₂ , Pd (CH ₃ COO) ₂ and Pd (II) acetylacetonate are preferred.

The respective palladium-containing catalyst can e.g. B. in an amount of 0.001 up to 10 mol%, preferably on the diazonium salt of the formula (IV).

Preferred reaction temperatures are those from +20 to + 80 ° C, in particular those from +40 to + 65 ° C.

The process according to the invention can optionally be carried out with the addition of simple solvents. Water, C ₁ -C ₆ alkyl alcohols, formic acid, tetrahydrofuran and acetonitrile are suitable, for example.

The diazonium salts of the formula (IV) can be prepared in a manner known per se (see, for example Houben-Weyl, volume X / 3, pages 7 to 113 from the corresponding anilines Reaction with sodium nitrite in acidic aqueous solution or by reacting Methyl nitrite can be produced in acidic methanol. The diazonium salts can in Form of the reaction mixture resulting from their production in the inventive methods are used, preferably after the destruction of any nitrite still present. Isolation of the diazonium salts is not mandatory.

Preferred compounds of the formula (V) are acrylic acid, methacrylic acid, Acrylamide and methacrylamide.

Based on 1 mol of diazonium salt of the formula (IV), z. B. 0.5 to 2 moles Use acrylic or acrylic acid derivatives of formula (V). This is preferably located Amount at 0.9 to 1.5 moles.

The process according to the invention can, for. B. perform so that you first from an aniline of the formula


in the
R ¹ , R ² , R ³ and R ^{4 have} the meaning given for formula (III),
with sodium nitrite in sulfuric acid aqueous solution or with an alkyl nitrite such as methyl, ethyl, butyl or amyl nitrite, preferably methyl nitrite in acid, e.g. B. sulfuric acid methanol converted into a diazonium salt of the formula (IV), any nitrite present in the reaction mixture obtained is destroyed by adding amidosulfonic acid, the reaction mixture thus treated to a mixture of acrylic acid or an acrylic acid derivative of the formula (V) with a homogeneous, containing palladium Catalyst and optionally a simple solvent such as water, methanol, ethanol or isopropanol are added dropwise at the reaction temperature and, if appropriate after a subsequent stirring time, the product of the formula (III) prepared, if appropriate after cooling and / or dilution with water, for. B. by filtration, distillation or phase separation.

The method according to the invention has the advantages that it is simple to use low temperatures, in short reaction times, without base additions and without essential additions of arylphosphanes polyhalogen-substituted cinnamic acids and cinnamic acid derivatives in high yields. Besides, none special solvents such as dimethylformamide.

The present invention further relates to new polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula


in the
R ^{2 '} for chlorine and R ^4' for fluorine or
R ^{2 'is} fluorine and R ^{4' is} chlorine.

One possibility for the preparation of the new compounds of the formula (III ') is above have been described. Their usability is explained below.

The polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula (III) including those of the formula (III ') can be obtained by hydrogenation of the double bond (step 1) and subsequent cyclization (step 2) in indanone derivatives of the formula


in the
R ¹ to R ^{4 have} the meaning given for formula (III) and
R ^{8 represents} hydrogen, bromine, chlorine or optionally substituted C ₁ -C ₁₀ alkyl.

Compounds of the general formula (VIIa) in which R ^{8 is} hydrogen can be converted in a manner known per se by halogenation into the corresponding compounds of the general formula (VIIa) in which R ^{8 is} bromine or chlorine.

Furthermore, compounds of the general formula (VIIa) in which R ^{8 is} bromine or chlorine can be converted in a manner known per se, for example by palladium-catalyzed carbonylation reactions with carbon monoxide and a suitable nucleophile, into indanone derivatives of the formula (VIIb),


in the
R ¹ to R ^{4 have} the meaning given for formula (III) and
R ^{9 represents} COOH, CONH ₂ or COOR ¹⁰ , where
R ^{10 is} C ₁ -C ₄ alkyl.

One can carry out the first step, for example, in the presence of Platinum or palladium, optionally hydrogenated with hydrogen at elevated pressure and perform the 2nd step, for example, by taking the obtained Arylpropionic acids are converted into the corresponding acid chlorides and these with Help from Friedel-Crafts catalysts to the indanones of the general formula (VIIa) cyclized.

These indanones and those of the formula (VIIb) are agro- and active pharmaceutical ingredients and liquid-crystalline materials analogously known Process (see e.g. WO 95/29171, EP-A 538 134, EP-A 401 166 and JP-OS 06-263 663) accessible.

The new compounds of formula (III ') expand the range of available standing indanones and thus potential active ingredients on the agro and Manufacture and test pharmaceutical field as well as in the field of liquid crystalline substances.

Examples example 1 2,4-difluorocinnamic acid

62 ml of concentrated sulfuric acid were added to 236 ml of water at 5 ° C. cooled and 38.7 g of 2,4-difluoroaniline added. A solution became at 0 to 2 ° C added dropwise from 23.9 g of sodium nitrite in 45 ml of water within 40 minutes and Stirred for 30 minutes. Then enough amidosulfonic acid was added that excess nitrite was destroyed. 0.34 g was added to 25.8 g of acrylic acid Tris (dibenzylidene acetone) dipalladium (0) and the at 40 ° C for 4 hours Diazonium salt solution was added dropwise and the mixture was stirred for 2 hours. After on After cooling to room temperature, 47.5 g of difluorocinnamic acid were isolated by filtration (86% yield of theory; melting point: 203 ° C.).

Example 2 2,4-difluorocinnamic acid

To a mixture of 124 ml concentrated sulfuric acid and 472 ml water 77.5 g of difluoroaniline were added dropwise at 0.degree. Then at 0 ° C Solution of 48.3 g of sodium nitrite in 90 ml of water was added dropwise in 30 minutes, so that the temperature could be kept. Then was 30 minutes at 0 ° C stirred. Excess nitrite was destroyed by the addition of sulfamic acid.

0.1 g of palladium (II) acetylacetonate was added to 54.8 g of acrylic acid and at 50 ° C. heated. At this temperature, the diazonium salt solution was in 4 hours added dropwise and stirred for a further 2 hours. After cooled to room temperature the solid was isolated by filtration, washed with water and dried (99.6 g; 90% yield of theory; melting point: 203 to 205 ° C).

Example 3 4-bromo-2-fluorocinnamic acid

62 ml of sulfuric acid were added to 236 ml of water and cooled to 5 ° C. at 57.0 g of 4-bromo-2-fluoroaniline were added to this temperature and at 0 to 2 ° C. a solution of 24.2 g sodium nitrite in 45 ml water within 30 minutes added dropwise and stirred for 20 minutes. Then 2.8 g was added Amidosulfonic acid too.

5 ml of the diazonium salt solution were added dropwise to 27.5 g of acrylic acid at 40 ° C. 0.23 g of palladium (II) acetylacetonate and within 20 minutes remaining diazonium salt solution added dropwise. The mixture was stirred at 40 ° C for 4 hours. The mixture was allowed to cool to room temperature and the product was isolated by filtration. After drying, 54.4 g of 4-bromo-2-fluorocinnamic acid were present (74% of theory; Melting point: 218 ° C).

Example 4 2,4-dichlorocinnamic acid

From 35 g of sodium nitrite in a methanol (20 ml) / water (60 ml) mixture by adding 30 ml of 50% sulfuric acid (30 ml) of gaseous methyl nitrite shown that at 0 ° C in a mixture of 250 ml of water, 60 ml of conc. Sulfuric acid and 53.5 g of 2,4-dichloroaniline was introduced. It has been 1 hour stirred. Excess methyl nitrite was removed by passing a Nitrogen stream and addition of 3 g of amidosulfonic acid removed. This solution was over 2 hours at 40 ° C to a solution of 0.25 g palladium (II) acetylacetonate and 30 g Acrylic acid added and stirred for 2 hours. After cooling down The precipitate was filtered and dried at room temperature. It turned out 58.1 g of 2,4-dichlorocinnamic acid (81% yield of theory; melting point: 230 ° C.).

Example 5 2,4-difluorocinnamic acid

To a mixture of 124 ml conc. Sulfuric acid and 472 ml of water were added 0 ° C 77.5 g of difluoroaniline added dropwise. A solution was then removed at 0 ° C 48.3 g of sodium nitrite in 90 ml of water were added dropwise so that the temperature was maintained could be. The mixture was then stirred at 0 ° C for 30 minutes. Excess nitrite was destroyed by the addition of sulfamic acid.

0.34 g of palladium (II) acetate was added to 54.8 g of acrylic acid and at 47 ° C. heated. At this temperature, the diazonium salt solution became so in 2 hours added dropwise that the temperature did not exceed 49 ° C., then was continued for a further 2 hours stirred. After cooling to room temperature, the solid became isolated by filtration, washed with water and dried. This gave 105.1 g 2,4-difluorocinnamic acid (95% yield of theory; melting point 204-205 ° C).

Example 6 3- (2,4-difluorophenyl) -2-methyl acrylic acid

To a mixture of 124 ml conc. Sulfuric acid and 472 ml of water were added 0 ° C 77.5 g of difluoroaniline added dropwise. A solution was then removed at 0 ° C 48.3 g of sodium nitrite in 90 ml of water were added dropwise so that the temperature was maintained could be followed by stirring at 0 ° C for 30 minutes. excess Nitrite was destroyed by the addition of sulfamic acid.

0.34 g of palladium (II) acetate was added to 60.1 g of methacrylic acid and at 45 ° C. heated. At this temperature, the diazonium salt solution became so in 2 hours added dropwise that the temperature did not exceed 50 ° C, then was a further 2 hours stirred. After cooling to room temperature, the solid became isolated by filtration, washed with water and dried. It turned out 118.0 g of 3- (2,4-difluorophenyl) -2-methylacrylic acid (85% yield of theory; Melting point 140-142 ° C).

Example 7 3- (2,4-difluorophenyl) propionic acid (not according to the invention)

105 g of 2,4-difluorocinnamic acid from Example 5 were dissolved in 450 ml of tetrahydrofuran and with 5 g of palladium on active cooling with stirring at 100 ° C. and 50 bar Hydrogen pressure implemented. After constant pressure was reached Cooled to room temperature, let down, the palladium catalyst filtered off and the solvent distilled off. After drying in vacuo, 104.1 g were obtained 3- (2,4-difluorophenyl) propionic acid (98% of theory; melting point: 100-102 ° C).

Example 8 2,5-difluoro-4-chlorocinnamic

To a mixture of 124 ml conc. Sulfuric acid and 472 ml of water were added 98.2 g of 2,5-difluoro-4-chloroaniline were added dropwise. Then at 0 ° C Solution of 48.3 g of sodium nitrite in 90 ml of water was added dropwise so that the temperature could be held. The mixture was then stirred at 0 ° C for 30 minutes. Excess nitrite was destroyed by the addition of sulfamic acid.

0.34 g of palladium (II) acetate was added to 54.8 g of acrylic acid and at 47 ° C. heated. At this temperature, the diazonium salt solution became so in 2 hours added dropwise that the temperature did not exceed 49 ° C., then was continued for a further 2 hours stirred. After cooling to room temperature, the solid became isolated by filtration, washed with water and dried. This gave 116.7 g 2,5-difluoro-4-chlorocinnamic acid (89% yield of theory).

Example 9 2,5-difluoro-3-chlorocinnamic

To a mixture of 124 ml conc. Sulfuric acid and 472 ml of water were added 98.2 g of 2,5-difluoro-3-chloroaniline were added dropwise. Then at 0 ° C Solution of 48.3 g of sodium nitrite in 90 ml of water was added dropwise so that the temperature could be held. The mixture was then stirred at 0 ° C for 30 minutes. Excess nitrite was destroyed by the addition of sulfamic acid.

0.34 g of palladium (II) acetate was added to 54.8 g of acrylic acid and at 47 ° C. heated. At this temperature, the diazonium salt solution became so in 2 hours added dropwise that the temperature did not exceed 49 ° C., then was continued for a further 2 hours stirred. After cooling to room temperature, the solid became isolated by filtration, washed with water and dried. This gave 108.9 g 2,5-difluoro-3-chlorocinnamic acid (83% yield of theory).

Example 10 2,3,4,5-Tetrachlorzimtsäure

To a mixture of 124 ml conc. Sulfuric acid and 472 ml of water were added 98.2 g of 2,3,4,5-tetrachloroaniline were added dropwise. Then at 0 ° C Solution of 48.3 g of sodium nitrite in 90 ml of water was added dropwise so that the temperature could be held. The mixture was then stirred at 0 ° C for 30 minutes. Excess nitrite was destroyed by the addition of sulfamic acid.

0.34 g of palladium (II) acetate was added to 54.8 g of acrylic acid and at 47 ° C. heated. At this temperature, the diazonium salt solution became so in 2 hours added dropwise that the temperature did not exceed 49 ° C., then was continued for a further 2 hours stirred. After cooling to room temperature, the solid became isolated by filtration, washed with water and dried. This gave 144.1 g 2,3,4,5-tetrachlorocinnamic acid (84% yield of theory).

Example 11 3- (2,4-difluorophenyl) propionic acid (not according to the invention)

The procedure was as in Example 5, but the 2,4-difluorocinnamic acid obtained was not isolated. The aqueous acid product suspension obtained was further Stirring at 50 ° C with 2 g Pd / C (5%) and heated to 100 ° C. Subsequently was injected up to 5 bar hydrogen. After reaching constant pressure cooled to room temperature, decompressed and the solid filtered off. The The filter cake was taken up in methylene chloride and the palladium catalyst was filtered off and the solvent is removed. After drying in vacuo, 100.5 g were obtained 3- (2,4-difluorophenyl) propionic acid (90% of theory; melting point: 100 ° C).

Example 12 3- (2,4-difluorophenyl) propionic acid (not according to the invention)

The procedure was as in Example 11, but the addition of palladium without activated carbon. There were 98.3 g of 3- (2,4-difluorophenyl) propionic acid (88% of theory).

Example 13 3- (2,4-difluorophenyl) propionic acid (not according to the invention)

The procedure was as in Example 5, but the 2,4-difluorocinnamic acid obtained was not isolated. The aqueous-acidic product suspension obtained was washed with sodium hydroxide solution made alkaline and mixed with further stirring at 50 ° C with 2 g Pd / C (5%) and heated to 100 ° C. Hydrogen was then injected up to 5 bar. After constant pressure was reached, the mixture was cooled to room temperature and the pressure was released and the palladium catalyst is filtered off. The alkaline product solution was with Acidified sulfuric acid and the product precipitate isolated by filtration. To drying in vacuo gave 95.0 g of 3- (2,4-difluorophenyl) propionic acid (85% of theory).

Example 14 4,6-difluoroindan-1-one (not according to the invention)

To a solution of 3- (2,4-difluorophenyl) propionic acid (57 g) in methylene chloride (200 ml) thionyl chloride (54.6 g) was added dropwise at 40 ° C. After the reaction has ended excess thionyl chloride and the solvent were distilled off. The oily The residue was added dropwise at 40 ° C. to a suspension of aluminum chloride (88.5 g) in methylene chloride (200 ml). The reaction mixture became after 18 hours 40 ° C added to dilute hydrochloric acid. The aqueous phase was separated off and extracted once with methylene chloride (250 ml). The combined organic phases were freed from the solvent and then distilled in vacuo. It 41 g of a colorless solid were obtained (mp: 103 ° C.).

Example 15 4,6-dichloroindan-1-one (not according to the invention)

To a solution of 3- (2,4-dichlorophenyl) propionic acid (43.8 g) in methylene chloride (200 ml) was dropped at 40 ° C thionyl chloride (36.9 g). After the reaction has ended excess thionyl chloride and the solvent were distilled off. The oily The residue was added dropwise at 40 ° C. to a suspension of aluminum chloride (53.3 g) in methylene chloride (200 ml). The reaction mixture became after 18 hours 40 ° C added to dilute hydrochloric acid. The aqueous phase was separated off and extracted once with methylene chloride (250 ml). The combined organic phases were freed from the solvent. The residue was made from cyclohexane recrystallized. 30 g of a colorless solid were obtained (mp: 115-116 ° C.).

Example 16 5,7-dichloroindan-1-one (not according to the invention)

To a solution of 3- (3,5-dichlorophenyl) propionic acid (54.8 g) in methylene chloride (200 ml) thionyl chloride (45.2 g) was added dropwise at 40 ° C. After the reaction has ended excess thionyl chloride and the solvent were distilled off. The oily The residue was added dropwise at 40 ° C. to a suspension of aluminum chloride (66.7 g) in methylene chloride (200 ml). The reaction mixture became after 18 hours 40 ° C added to dilute hydrochloric acid. The aqueous phase was separated off and extracted once with methylene chloride (250 ml). The combined organic phases were freed from the solvent. The residue was made from cyclohexane recrystallized. 36 g of a colorless solid were obtained (mp: 119-120 ° C.).

Example 17

Analogously to Example 5, starting from 2-chloro-5-fluoroaniline in a yield of 80% of theory. Th. 2-chloro-5-fluorocinnamic acid. The melting point of this cinnamic acid was 182 ° C, the ¹ H-NMR spectrum showed characteristic absorptions at 6.6 ppm (d), 7.25 ppm (m), 7.5 ppm (m) and 7.75 (m) , recorded in DMSO.

Example 18

Analogously to Example 5, starting from 2-fluoro-5-chloroaniline in a yield of 81% of theory. Th. 2-fluoro-5-chloro-cinnamic acid. The melting point of this cinnamic acid was 183 ° C, the ¹ H-NMR spectrum showed characteristic absorptions at 6.6 ppm (d), 7.25 ppm (t), 7.45 ppm (m), 7.55 ppm (d ) and 7.9 ppm (m), recorded in DMSO.

Claims (8)

1. Process for the preparation of polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula (III)


in the
R ¹ , R ² , R ³ and R ^{4 are the} same or different and each represents hydrogen, fluorine, chlorine or bromine, at least two of these radicals being different from hydrogen and
X represents OR ⁵ or N (R ⁶ ) (R ⁷ ), where
R ^{5 represents} hydrogen or optionally substituted C ₁ -C ₁₀ alkyl, optionally substituted phenyl or benzyl and
R ⁶ and R ^{7 are the} same or different and each represents optionally substituted C ₁ -C ₁₀ alkyl and
R ^{8 represents} hydrogen, chlorine or bromine or optionally substituted C ₁ -C ₁₀ alkyl,
characterized in that a diazonium salt of the formula (IV)


in the
R ¹ , R ² , R ³ and R ^{4 have} the meaning given for formula (III) and
A ^{⊖ stands} for one equivalent of halide, hydrogen sulfate, nitrate, acetate or tetrafluoroborate ions or for S equivalent of sulfate ions or for 1/3 equivalent of phosphate ions,
with acrylic acid or an acrylic acid derivative of the formula (V)


in the
X has the meaning given for formula (III) and
R ^{8 represents} hydrogen, chlorine or bromine or optionally substituted C ₁ -C ₁₀ alkyl,
in the presence of a homogeneous, palladium-containing catalyst at -5 to + 100 ° C. 2. The method according to claim 1, characterized in that in the formulas R ^{1 is} hydrogen or chlorine, R ^{2 is} hydrogen, fluorine, chlorine or bromine, R ^{3 is} hydrogen or chlorine and R ^{4 is} fluorine or chlorine, at least one the radicals R ¹ , R ² and R ^{3 are} different from hydrogen,
R ^{5 represents} hydrogen, methyl, ethyl, isopropyl or benzyl,
R ⁶ and R ^{7 represent} methyl or ethyl,
R ^{8 represents} hydrogen or methyl and
A ^⊖ for one equivalent of chloride, hydrogen sulfate or acetate or for S equivalent of sulfate. 3. Process according to claims 1 to 2, characterized in that the catalysts are PdCl ₂ , PdBr ₂ , Pd (NO ₃ ) ₂ , H ₂ PdCl ₄ , Pd (CH ₃ COO) ₂ , Na ₂ PdCl ₄ , K ₂ PdCl ₄ , Pd (II) acetylacetonate, tetra (trisphenylphosphine) Pd or tris (dibenzylidene acetone) Pd ₂ in amounts of 0.001 to 10 mol%, based on the diazonium salt of the formula (IV). 4. The method according to claims 1 to 3, characterized in that the Diazonium salts of formula (IV) from the corresponding anilines Reaction with sodium nitrite in acidic, aqueous solution or by reaction with an alkyl nitrite in acidic methanol and it in the form of used in their production reaction mixtures. 5. The method according to claims 1 to 4, characterized in that one per Moles of diazonium salt of the formula (IV) 0.5 to 2 moles of acrylic acid or Acrylic acid derivatives of the formula (V) are used. 6. Polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula


in the
R ^{2 '} for chlorine and R ^4' for fluorine or
R ^{2 'is} fluorine and R ^{4' is} chlorine. 7. Use of polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula (III) for the preparation of indanone derivatives of the formula


in the
R ¹ , R ² , R ³ and R ^{4 are the} same or different and each represents hydrogen, fluorine, chlorine or bromine, at least two of these radicals being different from hydrogen and
R ^{9 represents} COOH, CONH ₂ or COOR ¹⁰ , where
R ^{10 is} C ₁ -C ₄ alkyl. 8. Use of polyhalogenated cinnamic acids and cinnamic acid derivatives of the formula (III) for the preparation of indanone derivatives of the formula


in the
R ¹ , R ² , R ³ and R ^{4 are the} same or different and each represents hydrogen, fluorine, chlorine or bromine, at least two of these radicals being different from hydrogen and
R ^{8 represents} hydrogen, chlorine, bromine or optionally substituted C ₁ -C ₁₀ alkyl.