AU602699B2 - Substituted phenyl alpha-fluoroacrylates - Google Patents

Abstract

Certain esters of alpha -fluoroacrylic acid are available via hydrolysis of alpha -hydroxymethyl- alpha -fluoromalonic esters, followed by decarboxylation of the hydrolysis product. Phenyl alpha -fluoroacrylates which are substituted on the phenyl radical can be prepared by hydroxymethylation of dimethyl alpha -fluoromalonates, decarboxylation and dehydration of the resultant dimethyl alpha -hydroxymethyl- alpha -fluoromalonate and esterification of the resultant alpha -fluoroacrylic acid with substituted phenols. The substituted phenyl alpha -fluoroacrylates are colourless liquids or colourless solids which are polymerisable. They are suitable as starting material for the preparation of fluorinated polymers.

Description

Zii COMMONWEALTH OF AUSTRALIA 29 PATENTS ACT 1852-69 o 0 COMPLETE SPECIFICATION

(ORIGINALW

Class lot. Clans Application Number Lodged: ecor.4iete Specificatic Lodged: Prk'rty: Related Art: Accepted: Published: This doc'mnlit coj a:"7,I amrendm.,nq~ c~ FSacuu11 4 a,-id is .'r1 Name of Applicant'- Ad dress of Applicant; Aqtual Inventor: Address for Service: HOECHST AKTIENGESELLSCHAFT 45 Bruningstrasse, D-6230 Frankfurt/Main 80, Federal Republic of Germany RUDOLF HEUMULLER, PETER HERBRECHTSMEISER, GUNTER SIEGEMUND and WERNER GROH EDWD. WATERS SONS, 50 QUEEN STREET, MELBOUIE, AUSTRALIA, 3000.

J~j Complete Specification for the Invention entitled: SUBSTITUTED PHENYL OrLFLUOROACRYLATES The following statement Is a lull destirlption of this Invention, Including the best method of performing It known to I- us 1, -1 ~L HOECHST AKTIENGESELLSCHAFT HOE 86/F 136 Dr.DA/nmu Substituted phenyl a-fluortacrytates The invention relates to esters of ct-afLuoroacryLic acid with substituted phenols, a process for the preparation of these esters and their use.

Esters of a-fluoroacrylic acid are already known. Thus the pheny ester of c-fluoroacrylic acid is prepared by reacting ethyl monofluoroacetate in the presence of sodium ethylate with ethyl oxalate, converting the sodium ac-fluoroacrylate obtained into a-fluoroacryLoyl chloride by means of thionyl chloride and then esterifying this product with phenol (German Patent NV. 2,950,491 US Patent No. 4,297,466). It is a disadvantage in this process that ethyl monofluoroacetate, which is highly toxic, has to be empLoyed. Phenyl a-fluoroacrylate can be polymerized and is used for the preparation of polymers which, at roum temperature, are translucent or transparent or light-transmissive, colorless solids.

Other esters of a-fiuoroacrylic acid, in particular butyl a-fluoroacrylate, can be prepared by acid hydrolysis of the appropriate a-hydroxymethyl-a-fluoromaonate followed by decarboxylation of the hydrolysic product with simultaneous elimination of alcoho (British Patent No.

1,115,287). This method is, however, only described for the example of butyl ac-fluoroacrylate; the ester rapidly polymerizes under the influence of light.

,4 Polymers of fluorinated icrylic acid esters are also known, which correspond to the formula RHC=CR-CO-OR 1 in which R is a hydrogen atom, a methyl group or a halogen atom and R 1 is a fluorinatod alkyl or aryL radical (Us Patent No. 2,877,207); the fluoroalky radical of the alcohol component is, in partieular, a radical containing two hydrogen atoms on the carbon atom in the 1-poEition and no detailed statements at all are made i ii I- aq~rm~p-~uu -2 concerning suitable aryl radicals.

It is also known that polymers of a-halogenoacrylic acid esters with halogen-containing alcohol components are used for the preparation of radiation-sensitive protective Layers (US Patent No. 4,259,407). The starting materials used are monomers of the formula H 2 C CX-COGR in which X is a fluorine, chlorine or bromine atom and R represents a fLuorinated alkyl, aryl or alkoxy group.

Amongst the polymers containing an aromatic alcohol component, only poly-(m-trifluoromethylphenyl a-fluoroacrylate) is mentioned by name; there is, however, no information at all about any properties of this polymer or the corresponding monomer.

Finally, it is also known that polymers of a-fluoroacrylic acid esters are suitable as the core material for optical fibers (European published application 0,128,517).

Phenyl a-fluoroacrylate is the only ester having an S 20 aromatic alcohol component which is shown in terms of a formula, but there is no information at all on the S0 preparation and properties of this ester.

The object of the invention is to provide esters of a-fluoroacrylic acid with substituted phenols which tan C 1 be prepared in an economical manner using starting terc: ials of as low toxicity as possible and which can be porymerized to give products having a high transmittance of Light.

3 0 a fThe invention relates to phenyl a-fluorocrylates of the formuLa (1) H t CP C 0 I- -3 in which R denotes a halogenoalkyl group having 1 to 8 carbon atoms and p is nought, 1, 2 or 3, X denotes a halogen atom and n is nought or an integer from 1 to (it being possible for X to denote different halogen atoms if n is greater than Y denotes a hydrogen atom, a cyano group, the radical X or the radical R and m is nought or 1, the sum of n m denoting 1 to The invention also relates to a process for the preparation of a substituted phenyl a-fluoroacrylate, which comprises reacting dimethyl a-fluoromalonate with formaldehyde in a first process stage, then hydrolyzing, decarboxylating and dehydrating the resulting hydroxymethylated dimethyl ct-fluoromalonate in a second process S 15 stage and subsequently, in a third process stage, esterifying the resulting a-fluoroacrylic acid (if appropriate in the form of an acid halide) with a phenol of the formula HO (Y)

P

in which X, Y, R, n, m and p have the meaning indicated 0 in formula (if appropriate in the form of an alkali metal phenate).

Finally, the invention also relates to the use of sub- S stituted phenyl a-fluoroacrylates of the formula as a starting material for the preparation of polymers containing fluorine.

i t The process according to the invention is carried out in i three stages: dimethyl a-fluoromalonate is first reacted with formaldehyde to give dimethyl a-hydroxymethyl-afluoromalonate, the latter is then hydrolyzed and the hydrolysis product is decarboxylated and dehydrated, and finally, the resulting a-fluoroacrylic acid is esterified with a substituted phenol.

In the first process stage, dimethyl a-fluoromalonate is

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an rr ran ~,rrprx (rcC

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4subjected to hydroxymethylation with formaldehyde.

(Dimethyl a-fluoromalonate is a known compound; see Journal of Fluorine Chemistry 25 (1984), 203 212.) The formaldehyde is preferably employed in the form of an aqueous solution having a formaldehyde content of to 40% by weight. The formaldehyde is employed in an amount of 1 to 10 mol, preferably 1.1 to 3 mol (relative to 1 mol of dimethyl a-fLuoromalonate). It is also possible to use paraformaldehyde, hexamethylenetetramine or 1,3,5-trioxane instead of formaldehyde. It is advantagous to carry out the reaction in the presence of a basic catalyst, which is then used in an amount of 2 to preferably 5 to 15, mol (relative to the dimethyl C-fluoromalonate). The catalyst used is, in particular, 15 an alkali metal bicarbonate, for example potassium bicarbonate and sodium bicarbonate. The reaction is carried out at a temperature of 5 to 40 0 C, preferably 15 to The dimethyl a-hydroxymethyL-a-fluoromalonate formed is then isolated from the reaction mixture, preferably by salting out or extraction by means of a water-immiscible organic solvent. A suitable solvent is, above all, an aliphatic chlorinated hydrocarbon having 1 to 4 carbon atoms, for example methylene dichloride, chloroform, carbon tetrachloride, 1,1-dichloroethane or 1,2-dichloroethane. A combination of salting out and extraction is particularly advantageous; a saturated salt solution (ammonium sulfate or sodium chloride) is then first added to the reaction mixture, and this mixture is then extracted. Dimethyl a-hydroxymethyl-a-fluoromalonate is obtained in the form of a colorless solid by evaporating the solvent.

In the second process stage, the dimethyl a-hydroxymethyla-fluoromalonate is hydrolyzed in an aqueous acid medium, and the hydrolysis product is decarboxylated and dehydrated. The reaction is carried out at a pH from -1 to 6, preferably 0 to 2; the acid medium is prepared by means of an aqueous acid solution, preferably a dilute inorganic acid, such as hydrochloric acid or sulfuric ifr

C

ii

L

c 1

I

I:

i Ia,~n 5 acid. The reaction temperature is within the range from to 110 0 C, preferably 95 to 1050C. When the evolution of gas is complete, the reaction mixture is distilled under a pressure of 1013 to 600 mbar, and the 5 distillate is extracted with an organic solvent. The solvent used here is also a water-immiscible solvent, preferably an ether, such as diethyl ether. a-fluoroacrylic acid is obtained in the form of a colorless solid after the solvent has been removed by evaporation. In a preferred variant, the c-fluoroacrylic acid is isolated in the form of its ammonium salt. This is effected by passing gaseous ammonia through the solution obtained after the extraction, and then freeing the colorless crystalline precipitate from the solvent.

In the third process stage, the a-fluoroacrylic acid is esterified with a substituted phenol. The phenol is employed in an amount of 0.5 to 1.5 mol, preferably 0.8 to 1.2 mol (relative to 1 mol of a-fluoroacrylic acid),, In some cases if the acid is employed in the form of a halide the phenol is employed in the form of an alkali metal phenate, preferably sodium phenate or potassium phenate. The a-fluoroacrylic acid is employed for the esterification as such or, preferably, in the form of an acid halide, in particular as a-fluoroacryl chloride.

The acid halide is prepared by means of a customary halogenating agent, for example oxalyl chloride, phosphorus pentachloride, phosphorus trichloride, phosphorus oxychloride, benzoyl chloride, benzotrichloride, phosphorus tribromide, sulfur tetrafluoride and, especially, thionyl chloride. The halogenation by means of thicnylchloride is preferably carried out in the presence of a catalyst, such as dimethyl formamide. The reaction is carried out in an aromatic hydrocarbon, for example toluene, xylene and trimethylbenzene, as the solvent, and the reaction temperature is within the range from to 100 C, preferably 70 to 90 0

C.

The esterification is preferably carried out in a solvent o 1 -6and the reaction temperature in this case is -10 to 50 0

C,

preferably 0 to 25 0 C. The solvent used is a polar organic solvent, in particular a symmetrical, asymmetrical or cyclic ether, for example diethyl ether, dipropyl ether, diisopropyl ether, tert.-butyl methyl ether, tetrahydrofuran and dioxane, and aliphatic halogenated hydrocarbon, preferably a chlorinated hydrocarbon, for example methyLene dichloride, chloroform, carbon tetrachloride, 1,1-dichloroethane and 1,2-dichLoroethane, an aromatic halogenatic hydrocarbon, preferably a chlorinated hydrocarbon, for example chLorobenzene and 1,2-dichlorobenzene or !,3-dichlorobenzene, or an aliphatic or aromatic nitrile, for example acetonitrile and benzonitrile. The solvent can also be a mixture of sevoral polar solvents. It is expedient to carry out the esterification of the acid halide with the phenol in the presence of an organic base, in particular a trialkylamine having 1 to 4 carbon atoms in each of the alkyl groups. The base is employed in an amount of 0.5 to 2 mol. preferably 0.8 to 1.2 mol (relative to 1 mol of acid halide). The resulting substituted phenyl a-fluoroacrylate is isolated from the reaction mixture by distilo lation, preferably under a pressure of 1013 to 200 mbar, or after the Iolvent has been removed by distillation by hot extraction of the solid residue with a nonpolar solvent, preferably an aliphatic hydrocarbon, such as nhexane, and subsequent crystallization. It is expedient to carry out the distillation in the presence of a customary polymerization inhibitor, for example hydroquinone or hydroquinone monomethyl ether; this is used in an amount Sof 100 to 500 ppm (relative to a-fluoroacryloyl halide).

The bottom temperature is within the range from 20 to 100 0 C, preferably 30 to 85 0 C. The phenyl ester is purified further by being distilled again, preferably under reduced pressure, or recrystallized. The substituted phenyl a-fluoroacrylates according to the invention carry 1 to 5, preferably 2 to 5, substituents on the phenyl radical; preferred esters are those which contain, as substituents or in the substituent, a fluorine atom or several fluorine atoms.

J

-7 The esters according to the invention includle, for example, the following compounds: 2- or 3- or 4-fLuorophenyl c-fLuoroacrylate, 2- or 3- or 4-chiorophenyL af luoroacryLate, 2- or 3- or 4-bromophenyL c-f LuoroacryLate, 2- or 3- or 4-iodophenyL c-fLuoroacryLate, 2,3- or 2,4- or or 2,6- or 3,4- or 3,5-difLuorophenyL c-fLuoroacrylate, 2,3- or or 2,5- or 2,6- or 3,4- or dichiorophenyt c-fLuoroacryLate, 2- or 3-chLor-4-fLuoro-' phenyl ot-f Luo roac ryL ate, 2-bromo-4-ch Ioropheny I ct-fl uoroacryLate, 4-bromo-2-chLorophenyL c-ftuoroacryLate, 2,6dibromo-4-fLuorophenyL c-fLuoroacryLate, 4-bromo-2, 6dichLorophenyL a-fiuoroacryLate, 2,4-di chLoro-6-iodophenyL c-fLuoroacryLate, 2,3,4- or 2,3,5- or 2,3,6- or 2,4,5or 2,4,6- or 3,4,5-trichLoro-phenyL c-fLuoroacryL ate 2,4,6-tribromophenyL c-fLuoroacryLate, 2,4,6-triiodophenyL c-fLuoroacryL ate, 2,3,5,6-tetrafLuorophenyL ct-f Luoroacry'Late, 2,3,4,5-tetrachLorophenyL ct-fLuoroacryLato', 2,13,5,6-tetrachLorophenyL ct-f LuoroacryLate, pentaf'luoro- 4 phenyL c-fLuoroacryLate, pent ach LorophenyL c-fLuoroacryLate, pentabrornophenyL c-fLuoroacryLate, 2,6-diiodo-4-trifLuoroiethyLphenyL ot-fLuoroacryLate, 2- or 3- or 4-trifLuoromethyLphenyL c-fLuoroacryLate, 2-(heptaftuoro-2-propyL phenyL or 4-(heptafLuoro-2-propyL)-phenyL c-fLuoroacryLate, 2 o r 3e5 b is tr if Luo ro m eth yL )p he ny L a- fLu o ro a cryL a te 254cyaopenflx-uoroacryl ate, 2,6-dichloro-4-cyanophvenl t-luro 254anohey ctuoroacrylate, 2,6-dichromn-4-cyanopheny uoo ac ryLate, 2,6-d if Luoro-4-cyanophenyL at-f Luoroac ryL ate, 4-cyano-2,3,5,6-tetrafLuorophelyL c-fLuoroac ry~.ate, 4- (or 3,5)-difLuorophenyL c-fLuoroacryLate, 2chLoro-4.5- (or 4,6)-difLuorophelyt c-ftuoroacryLate, or 2,6- or 3,5-dichtoro-4-fLuoropheny( c-fLuoroacryLate, 2,6- or 3,4-dlibromo-3,4 (or 2,6)-dichLorophenyL ot-f Luoroacrylate, 2,4,6-trichLoro-3-f LuoropheiyL LuoroacryL ate, 2,4- or 2,6-d ichtoro-3-triftuoromethyLpheyLt c-fLuoroacryLate, 2,6-dibroino-4- (or 5) -trif uoromethyiphenyL otf LuoroacryLate, 2,4-dibronio-5- (or 6)-trif Luoromethyiphenyt c-f LuoroacryLate, 2- or 4-bromo-3- (or 5)-trif LuoromethyLphenyL c-fluoroacrylate, 2,3,6-tr ibrono,405-bisbromomethyLphenyL c-f LuoroacryL&-ee, 2,4,5-tr ibromo-3,6-bis- -8- (bromomethyL )phenyL ct-f Luoroac ryL ate, 2,4,6-tr i chioro- (chtoromethyL )phenyL t-f Luoroac ryL ate, 3,4,5tr ichLoro-2,6-b is( chLorome thy L phenyl cx-f Luoro a cryL ate, 2,4,6-tr ichLoro-3-chLoromethyLphenyL ca-fLuoroacryLate, 2,4-dibromo-6-dibroniomethy)KphenyL c-ftuoroacryL ate, 2,6dibromo-4-dibromomethyLphenyL c-f Luoroac ryl ate, 2,3,5,6tet rach Loro-4-c h Loromethy LphenyL a-f Luoroa c ryt ate, 2- or 3-f Luoro-4-rnethyLphenyL ca-f LuoroacryLate, 3- or 4- or fLuoro-2-methyLphenyL c-fLuoroac ryl ate, 2-f Luoro-6methyLphenyL c-f LuoroacryLate, 4-f (Uoro-3-methyLphenyL a-f lurroacry~ate, 2,4,6-tr ichLoro-3,5-dimethy Lph.enyL caf LuoroacryLate, 2,6-dichLoro-3,5-dimethyLphenyL a-f Luoroacrytate, 2,6-dichLoro-4-methyLphenyL c-f LuoracryLate, 2,4,6-tr ibromo-5,5-dimethyLphenyt ca-f LuoroacryL ate, 2,4,6tribromo-3-methyLphenyL a-fLuoroacryLate, 2,3,5,6-tetrafLuoro-4-cyanophenyL c-fLuoracryLate, 2- or 3- or 4methyiphenyL a-f LuoroacryLate, 2,3- or 2,4- or 2,5- or 2,6- or 3,4- or 3,5-diimethyLphenyL c-f Luoroac;-yLate, 202,4,6-trimethyLphenyL ca-f Luoroacry~ate, 2,3,5,6-tetracx-f LuoroacryLate, 2-or 3- or 4-isopr~pyLphenyl a-fLuoroac rylate, 4-isopropyL-3,5-dimethyLphenyL a-f LuoroacryLate and 2,3- or 2,5- or 2,6- or 3,4- or di isopropyLphenyl c-fLuoroacryLate.

The substituted phenyl esters of a-fLuoroacryLic acid are colorless Liquids or colorless solids at room temnperature. They are readily poLymerizabLe and are suitable for the preparation of crystal clear, Light-transmissive, V colorless polymers.

The f olLowing examples serve to iL Lustrate the invent ion 4 in greater dletail. Percentages relate in each case to w e ig ht.

ExampLe 1 a) 489g (0.48 rnoL) of potassium bicarbonate were dissolved i n 535 g (6 .59 moL of aqueous f ormaLd~inyde so Lut ion (37% strength by weight) in a 4-litre glass flask.

1: i~luux~"~~~ 9 841 g (5.6 mol) of dimethyl a-fLucromalonate were added dropwise to this solution, with stirring, in the course of 3 1/2 hours; the temperature was kept meanwhile within the range from 20 to 250C. Stirring was continued for 2 hours at the same temperature, and during this time dimethyl a-hydroxymethyl-a-fluoromalonate was precipitated in the form of a colorless solid. 2,500 g of an aqueous, saturated solution of ammonium sulfate were then added to the reaction mixture, which was then extracted with methylene dichloride. The extraction solution was dried by means of anhydrous sodium sulfate. 906 g (90% of theory) of dimethyl a-hydroxymethyl-a-fluoromalonate were obtained after removing the methylene dichl.eride by distillation (bath temperature 400C, 25 mbar).

b) 175 g (0.97 mol) of dimethyl a-hydroxymethyi-a-fluoromalonate, 750 ml of water and -5-0 ml of f ydro-ch-.oric acid (36% strength by weight) -6ere heat at the boil for 2 1/2 hours in a 2-Litre glass flask equipped with a thermometer and stirrer and a Vigreux column fitted with a distillation head. The temperature of the reaction mixture was 1030C. The reaction mixture was then distilled. 1 g of hydroquinone monomethyl ether was added to the distillate and the latter was extracted with diethyl ether, and the extraction solution was dried by means of anhydrous sodium sul-ate.

17 g (1 mol) of gaseous ammonia were then passed into the solution at room temperature. The colorless precipitate obtained thereby was filtered off, washed with diethyl ether and dried at room temperature under reduced pressure. 70.8 g (68% of theory) of ammonium a-fLuoroacrylate were obtained.

c) 100 g (0.934 mol) of ammonium a-fluoroacrylate were dispersed in a mixture of 600 g of mesitylene and ml of dimethylformamide in a 1-litre glass flask and 119 g (1.0 mot) of thionyl chloride were added in the course of one hour. The resulting mixture was heated zr c E rC Pt B pcCI CC P ttl tC

I

tc*t r F C ii i-o 1 aO 0 00 0 0 O 00 000000 0000 O0 S0 0 **a 00 o to 0 t a a 9€ at 9 10 to a temperature of 80 0 C and was kept at this temperature for 2 hours, with stirring. The Liquid obtained after the mixture had cooled to room temperature was distilled under reduced pressure, and the fraction obtained up to 100 0 C/160 mbar was distilled again under normal pressure.

67 g (66% of theory) of a-fluoroacryloyl chloride were obtained, boiling point 65 to 67 C.

d) A solution of 111g (0.5 mol) of potassium pentafluorophenate in 250 ml of anhydrous acetonitrile was added dropwise, in the course of 1 hour, at a temperature of 25 0 C and with stirring, to a solution of 54.5 g (0.502 mol) of a-fluoroacryloyl chlrcide in 100 ml of anhydrous acetone nitrile, and the reaction mixture 15 was then stirred for a further 2 hours at the same temperature. The solid formed was filtered off and wauhed with 100 ml of anhydrous acetonitrile. The mixture of filtrate and wash solution was distilled, after adding 0.01 g of hydroquinone monomethyl ether.

20 107.1 g (84% of theory) of penafluorophenyl a-fluoroacrylate were obtained, boiling point 41 to 42 0

C

(under 2 mbar).

Example 2 13.9 g (0.128 mol) of -fluoroacryluyl chloride (obtained in accordance with example 1c) were added dropwise, at a temperature of 25 0 C, with stirring and in the course of minutes, to a solution of 30 g (0.0985 mol) of potassium pentachlt ophenate in 400 ml of anhydrous acetonitrile, and the reaction mixture was then stirred for a further 90 minutes at the same temperature. The solid formed was filtered off and washed with 20 ml of anhydrous acetonitrile. After 0.01 g of hydroquinone monomethyl ether had been added, the volatile constituents in the mixture of filtrat and washing liquor were distilled off and the residue was recrystallized from boiling n-hexane.

17 g (51% of theory) of pentachlorophenyl c-ftuoroacrylate were obtained, melting point 90 to 92 0

C.

er 4 0 t to ii Example 3 49 g (0.181 mol) of 2,6-dibromo-4-fLuorophenoL were dissoLved in 150 mL of anhydrous methyLene dichioride, and 18.3 g (Q).181 mod) of triethylamine were added to the solution; 20 g (0.184 moL) of ca-fLuoroacryLoyL chloride (obtained in accordance with example 1c) were then added dropwise at a temperature of 50C, with stirring apd in the course of 30 minutes, and the reaction mixture was stirred for a further 30 minutes at the same temperature.

The solid formed was fi~tered off and washed with 30 ml of methyLene dichLoride. The mixture of filtrate and wash solution was distilled, after adding 0.01 g of hydroquinone monomethyL ether. 46 g (74% of theory) of 2,6-dibromo-4-fLuorophenyL a-fLuoroacryLate were obtained, boiling Point 86 to 88 0 C (under 0.4 mbar).

Example 4 2.2 g (0.02 moL) of c-fLuoroacryloyL chloride (obtained in accordance with example 1c) were added dropwise, at a temperature of 5 0 C, with stirring and in the course o f 5 inu t es, t o a s oLu t io n o f 7.-8 g 0 19 m o L) o f Z,6 dijodo-4-trifLuoromethypheiyt and 2 g (0.02 mol) of triethyLamine in 80 mt of anhyd -,ws methyLeoi~ *and the reactiri mixture was then stirred lt "i 0, minutes at the same temperature. Th! SO I was f iltered of f and washed wi th I) OnL of rethyLene dichLorideo After 0.00) gj of hydroq lrnoyt4 ,onomethyL ether had been added, the VoLatiLe co~nsti~uortts in the mixture of filtrate and wash solution were removed by dist iL Lat ion, and the res idue was rec ryst~i'LL ed I rbm boiling in-hexane. 7 g (76X of theory) of Zo6-ii -do-4trifluoromethyiphenyl t4-fl1uoroacrylate were obtin ?kt, Metrk.

point 93 to 95 0

C.

Example 16.2 g (0.1 moL) of 4-trifLuorometh 6soLved 12 in 80 ml of anhydrous diethyl ether, and 10.1 g (0.1 mol) of triethylamine were added in portions to the solution; 12 g (0.11 mlol) of a-fluoroacryloyl chloride (obtained in accordance with example Ic) were then added dropwise, at a temperature of 100C, with stirring, and in the course of 20 minutes, and the reaction mixture was stirred for a further 60 minutes at the same temperature.

The solid formed was filtered off and washed with 20 ml of diethyl ether. The mixture of filtrate and wash solution was distilled, after adding 0.005 g of hydroquinone monomethyl ether. 19.5 g (83% of theory) of 4-trifluoromethy phenyl a-fluoroacrylate were obtained, boiling point 69 to 70 0 C (under 3 mbar).

Example 6 5 g (0.169 mol) of 3-trifluoromethylphenol were dissolved in 100 ml of anhydrous methylene dichloride, and 17.1 g (0.769 mol) of triethylamine were added in portions to the solution; 20 g (0.184 mol) of O-fluoroacryloyl chloride (obtained in accordance with example 1c) j were then added dropwise, at a temperature of 5 0 C, with stirring and in the course of 20 minutes, and the reaction mixture 'as stirred for a further 60 minutes at the same i 25 temperature. The solid formed was filtered off and washed with 30 ml of methylene dichloride. The mixture of filtrate and wash solution was distilled, after adding 0.01 g of hydroquinone monomethyl ether. 27 g i (68% of theory) of 3-trifluoromethylphenyl a-fluoroacrylate were obtained, boiling point 78 to 79 0 C (under j 4 mbar).

Example 7 26.2 g (0.1 mol) bf 4-perfluoroisopropylphenol were dissolved in 100 ml of anhydrous diethyl ether, and 10.1 g (0.1 mol) of triethylamine were added to the solution; 12 g (0.11 mol) of a-fluoroacryloyl chloride (obtained in accordance with example 1c) were then added I i i In i In 13 dropwise, at a temperature of 10 0 C, with stirring and in the course of 15 minutes, and the reaction mixture was stirred for a further 30 minutes at the same temperature. The solid formed was filtered off and washed with 20 ml of diethyl ether. The mixture of filtrate and wash solution was distilled, after adding 0.005 g of hydroquinone monomethyl ether. 22.9 g (69% of theory) of 4-perfluoroisopropylphenyl a-fluoroacrylate were obtained, boiling point 65 to 66 0 C (under 1 mbar).

Example 8 cr s #*l@i Ctf Itc g (0.038 mol) of 2 -perfluoroisopropylphenol were dissolved in 30 ml of anhydrous diethyl ether, and 3.9 g 15 (0.038 mol) of triethylamine were added to the solution; 4.3 g (0.039 mol) of a-fluoroacryloyl chloride (obtained in accordance with example Ic) were then added dropwise, at a temperature of 10 0 C, with stirring and in the course of 12 minutes, and the reaction mixture was stirred for a further 30 minutes at the same temperature.

The solid formed was filtered off and washed with 10 mi of diethyl ether. The mixture of filtrate and wash solution was distilled after adding 0.002 g of hydroquinone monomethyl ether. 7 g (55% of theory) of 2-perfluoroisopropylphenyl a-fluoroacrylate were obtained, boiling point 85 0 C (under 1 mbar).

Example 9 10 g (0.092 mol) of a-fluoroacryLoyl chloride (obtained in accordance with example Ic) were added dropwise, at a temperature of 5 0 C, with stirring and in the course of minutes, to a solution of 10.7 g (0.09 mol) of 4-cyanophenol and 9.1 g (0.09 mol) of triethylamine in 150 ml of anhydrous methyleve dichloride, and the reaction mixture was then stirred for a further 30 minutes at the same temperature. The solid formed was filtered off and washed with 20 ml of anhydrous methylene dichloride.

After 0.005 g of hydroquinone monomethyl ether had been iI si; 5

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I. 14 added, the volatile constituents in the mixture of filtrate and wash sorution were removed by distillation, and the residue was recrystallized from boiling n-hexane.

11.2 g (65% of theory) of 4-cyanophenyl c-fluoroacrylate were obtained, melting point 78 to 79 0

C.

Example g (0.092 moL) of ac-fluoroacrytoyt chloride (obtained in accordance with example 1c) were added dropwise, at a temperature of 5 0 C, with stirring and in the course of minutes, to a solution of 16.7 g (0.089 moL) of dichloro-4-hydroxybenzonitrie and 9 g (0.089 moL) of triethyamine in 200 mL of anhydrous methylene dichloride, and the reaction mixture was then stirred for a further minutes at the same temperature. The solid formed was filtered off and washed with 20 mL of anhydrous methylene dichloride. After 0.005 g of hydroquinone monomethyl ether had been added, the "olatile constituents in the mixture of filtrate and wash solution were removed by distillation, and the residue was recrystaized from boiling n-heptane. 18.7 g (81% of theory) of 2,6dichloro-4-cyanophenyl a-fluoroacrylate were obtained, ui;lting point 95 to 990C.

S' Example 11 g (0.092 mot) a-fluoroacryLoy chLoride (obtained in accordance with example ic) were added dropwise, at a temperature of 5 0 C, with stirring and in the course of j 1 minutes, to a solution of 24.8 g (0.09 iol) of dibromo-4-hydroxybenzonitrie and 9.1 (009 mot) of triethylamine in 200 mi of anhydrous methyLene dichoride, and the reaction miyture was then stirred for a further 30 minutes at the same temperature. The solid formed was filtered off and washed with 20 ml of anhydrous methylene dichloride. After 0.005 g of hydroquinone monomethyL ether had been added, the volatile constituents in the mixture of filtrate and wash solution were removed by 1, 15 distillation, and the residue was recrystaLLized from boiling n-heptane. 17.5 g of tcheory) of 2,6-dibromo- 4-cyanophenyl ca-fLuoroacryLate werve obtained, meLcing point 135 to 1380C.

A

61

'I.

I

Claims (1)

16- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A phenyl a-fluoroacrylate of the formula (1) (c) n CH CF CO 0 (Y) in which R denotes a halogenoalkyl group having 1 to 8 carbon atoms and p is nought, 1, 2 or 3, X denotes a halogen atom and n is nought or an integer from I to 5 (it being possible for X to denote different halogen atoms if n is greater than Y denotes a hydrogen atom a cyano group, the radical X or the radical R and m is nought or 1, the sum of n m p being I to 2. A process for the preparation of a phenyl c-fluoro- acrylate, which comprises reacting dimethyl a-fluoromalonate with formaldehyde in a mol. ratio of 1:1-10 in a first process stage at a reaction temperature of 5 0 -40 0 C then hydrolizing, decarboxylating and dehydrating the resulting hydroxymethylated dimethyl a-fluoromalonate in a second process stage, at a reaction temperature of 90 0 -110°C and at pH 1 to 6 and subsequently esterifying, in a third process stage, at a reaction temperature of -10 0 -500C the resulting a-fluoroacrylic acid (if appropriate in the form of an acid halide) with a phenol of the formula itt a mol. ratio of 1:0.5-1.5 (X) t r c t H O Y) in which X, Y, R, n, m and p have the meaning indicated in formula (if appropriate in the form of an alkali metal phenate). Ji 3. The process as claimed in claim 2, wherein the first process stage is carried out at a temperature from to 40 0 C, the second process stage is carried out at a temperature from 90 to 110 0 C, and the third process stage is carried out at a temperature from -10 to 50 0 C. 4. The use of the phenyl a-fluoroacrylate of the formula as a starting material for the preparation of ~2I A 17 a fLuorine-.containing poLymer. DATED this 11th day of June 1987. HOECHST AKTIENGESELLSCHAFT a q r at 0~ t e a 'a I EDWD. WATERS SONS PATENT ATTORNEYS 50 QUEEN STREET MELBOURNE. VIC. 3000.