Note: Descriptions are shown in the official language in which they were submitted.
130qlO6
HOECHST AKTIENGESELLSCHAFT HOE 86/F 136 Dr.DA/mu
Substituted phenyl ~-fLuoroacrylates
The invention relates to esters of ~-fluoroacrylic acid
with substituted phenols, a process for the preparation
of these esters and their use.
Esters of ~-fluoroacrylic acid are already known. Thus
the phenyl ester of ~-fluoroacrylic acid is prepared by
reacting ethyl monofluoroacetate in the presence of
sodium ethylate with ethyl oxalate, converting the sodium
~-fluoroacrylate obtained into ~-fluoroacryloyl chloride
by means of th;onyl chloride and then esterifying this
product with phenol (German Patent No. 2,950,491 = US
Patent No. 4,297,4 6 6)~ 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 poly-
mers ~hich, at room temperature, are translucent or
transparent or light-transmissive, colorless solids.
Other esters of ~-fluoroacryl;c acid, in particular butyl
~-fluoroacrylate, can be prepared by acid hydrolysis of
the appropriate ~-hydroxymethyl-~-fluoromalonate followed
by decar~oxylation of the hydrolysis product with
simultaneous elimination of alcohol tBritish Patent No.
1,115,287). This method is, however, only descr;bed for
Z5 the example of butyl ~-fluoroacrylate; the ester rapidly
polymerizes under the influence of light.
Polymers of fluorinated acryl;c acid esters are also
kno~n, uh;ch correspond to the formula RHC=CR-CO-OR1
; ~ 3Q in ~hich R is a hydrogen atom, a methyl group or a halogen
atom and R1 is a fluorinated alkyl or aryl radical
tUS Patent No. 2,877,207); the fluoroalkyl radical af
the aLcohol component is, in particular, a radical con-
taining two hydrogen atoms on the carbon atom in the
1-position and no detailed statements at alL are made
~k
., i, .. .. . .
1 309 1 06
concerning suitable aryl radicals.
It is also known that polymers of ~-halogenoacrylic acid
esters with halogen-containing alcohol components are
used for the preparation of radiation-sensitive protect-
ive layers (US Patent No. 4,259,407). The starting
materials used are monomers of the formula H2C = CX-COOR
in which X is a fluorine, chlorine or bromine atom and
R represents a fluorinated alkyl, aryl or alkoxy group.
Amongst the polymers cuntaining an aromatic alcohol com-
ponent, only poly-(m-trifluoromethylphenyl ~-fluoro-
acrylate) 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 ~-fluoroacrylic
acid esters are suitable as the core material for optical
fibers (European published application 0,128~517).
Phenyl ~-fluoroacrylate is the only ester hav;ng an
aromatic alcohol component which is shown in terms of a
formula, but there ;s no information at a~l on the
preparation and properties of this ester.
The object of the invention is to provide esters of
~-fluoroacrylic acid with substituted phenols which can
be prepared in an economical manner using starting mater-
ials of as low toxicity as possible and which can be
polymerized to give products having a high transmittance
of light.
The invention relates to phenyl ~-fluoroacrylates of the
formula (1)
CN2 = C~ - CO - O ~ (~)m
: .
l s ~ u ~
-- 3
in which R denotes a halogenoalkyl group having 1 to 8
carbon atoms and p is o , 1, 2 or 3, X denotes a
halogen atom and n is or an integer from 1 to 5
(it being possible for X to denote different halogen
atoms if n is greater than 1), 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 denoting 1 to 5.
The invention also relates to a process for the prepar-
ation of a substituted phenyl ~-fluoroacrylate, which
comprises reacting dimethyl ~-fluoromalonate with formal-
dehyde in a first process stage, then hydrolyzing,
decarboxylating and dehydrating the resulting hydroxy-
methylated dimethyl ~-fluoromalonate in a second process
stage and subsequently, in a third process stage, esteri-
fying the resulting -fluoroacrylic acid tif appropriate
in the form of an acid halide) with a phenol o~ the
formuls (2) N0 ~ X)n
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).
Z5
Finally, the invention also relates to the use of sub-
stituted phenyl ~-fluoroacrylates of the formula (1) as a
starting mater;al for the preparation of polymers contain-
;ng fluorine.
The process according to the invention ;s carried out in
three stages: dimethyl ~-fluoromalonate is first reacted
~ith formaldehyde to give dimethyl~-hydroxymethyl-~-
fluoromalonate, the latter is then hydrolyzed and the
hydrolysis product is decarbo~ylated and dehydrated, and
finally, the resulting ~-fluoroacrylic acid ;s esterified
with a substituted phenol.
In the first process stage, dimethyl ~-fluoromalonate is
i,., ~., . ~,
--" 1 309 1 06
-- 4
subjected to hydroxymethylation with formaldehyde.
tDimethyl ~-fluoromalonate is a known compound; see
Journal of Fluorine Chenlistry 25 (1984)~ 203 - 212.)
The formaldehyde is preferably employed in the form of
an aqueous solution having a formaldehyde content of 30
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 ~-fluoromalonate). It is also
possible to use paraformaldehyde, hexamethylenetetramine
or 1,3,5-trioxane instead of formaldehyde. It is advant-
agous to carry out the reaction in the presence of a
basic catalyst, which is then used in an amount of 2 to
_ . .
S0~ preferably S to 15, mol % (relative to the dimethyl
a-fluoromalonate). The catalyst used is, in particular,
an alkali metal bicarbonate, for example potassium bi-
carbonate and sodium bicarbonate. The reaction is car-
ried out at a temperature of S to 40C, preferably 15 to
30C. The dimethyl a-hydroxymethyl-~-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, ~or example methylene dichloride,
chloroform, carbon tetrachloride, 1,1-dichloroethane or
1,Z-d;chloroethane. 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 ~-hydroxymethyl-~-fluoro-
malonate is obtained in the form of a colorless solid byevaporating the solvent.
In the second process stage, the dimethyl ~-hydroxymethyl-
~-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 med;um ;s prepared
by means of an aqueous acid solution, preferably a dilute
inorganic acid, such as hydrochloric acid or sulfuric
-` 1 309 1 06
acid. The reaction temperature is with;n the range from
90 to 110C, preferably 95 to 105C. When the
evolution of gas is complete, the reaction mixture is
distilled under a pressure of 1013 to 600 mbar, and the
distillate is extracted with an organic solvent. The
solvent used here is also a water-immiscible solvent,
preferably an ether, such as diethyl ether. -fluoro-
acrylic acid is obtained in the form of a colorless solid
after the solvent has been removed by evaporation. In a
preferred variant, the -fluoroacrylic acid is isoLated
;n 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 precip;tate from the solvent.
- In the third process stage, the ~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 l mol of ~-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 ~-fluoroacrylic acid is employed for the
esterification as such or, preferably, in the form of an
acid halide, in particular as ~-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 thionyl-
chloride 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 ~rimethylbenzene, as the solvent,
and the reaction temperature is w;thin the range from 50
to 100C, preferably 70 to 90C.
The esterification is preferably carried out in a solvent
, . ,~ , .. . . . .
-- 6
and the reaction temperature in this case ;s -10 to 50C,
preferably 0 to 25C. The solvent used is a polar
organic solvent, in part;cular a symmetr;cal, asymmetrical
or cyclic e~her, 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 tetra-
chloride, 1,1-dichloroethane and 1,2-dichloroethane, an
aromatic halo~enatic hydrocarbon, preferably a chlorinated
hydrocarbon, for example chlorobenzene and 1,Z-dichloro-
benzene or 1,3-dichlorobenzene, or an aliphatic or
aromatic nitrile, for example acetonitrile and benzo-
nitrile. The solvent can also be a mixture of several
polar solvents. It is expedient to carry out the ester-
- ification of the acid halide with the phenol in the
presence of an organic base, in particular a trialkyl-
amine 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 mo; of
acid halide)~ The resulting substituted phenyl ~-fluoro-
acrylate is isolated from the reaction mixture by distil-
lation, preferably under a pressure of 1013 to 200 mbar,
or - after the solvent has been removed by distillation -
by hot extract;on of the solid residue with a nonpolarsolvent, pre~erably an aliphatic hydrocarbon, such as n-
hexane, and subsequent crystallization. It is expedient to
carry out the dist;llation in the presence of a customary
polymerization inhibitor, for example hydroquinone or
hydroquinone monomethyl ether; this is used in an amount
of 100 to 500 ppm (relative to ~-fluoroacryloyl halide).
The bottom temperature is within the range from 20 to
100C, preferably 3û to 85C. The phenyl ester is purified
further by being distilled again, preferably under reduced
pressure, or recrystallized. The substituted phenyl a-fluoro-
acrylates according to the invent1on carry 1 to 5, preferably
2 to 5, substituents on the phenyl rad;cal; preferred esters are
those which contain, as substi~uents or in the substituent, a
fluorine atom or several fluorine atoms.
1 309 1 06
,, . ~
-- 7
The esters according to the invention include, for
example, the follow;ng compounds: 2- or 3- or 4-fluoro-
phenyl a-fluoroacrylate, 2- or 3- or 4-chlorophenyl a-
fluoroacrylate, 2- or 3- or 4-bromophenyl a-fluoroacrylate,
2- or 3- or 4 iodophenyl a-fluoroacrylate, 2,3- or 2,4- or
2,5- or 2,6- or 3,4- or 3,5-difluorophenyl a-fluoro-
acrylate, 2,3- or 2,4- or 2,5- or 2,6- or 3,4- or 3,5-
d;chlorophenyl a-fltloroacrylate, 2- or 3-chlor-4-fluoro-
phenyl a-fluoroacrylate, 2-bromo-4-chloro~henyl a-fluoro-
acrylate, 4-bromo-2-chlorophenyl -fluoroacrylate, 2,6-
d;bromo-4-fluorophenyl a-fluoroacrylate, 4-bromo-2,6-
dichlorophenyl a-fluoroacrylate, 2,4-dichloro-6-iodophenyl
a-fluoroacrylate, 2,3,4- or 2,3,5- or 2,3,6- or 2,4,5-
or 2,4,6- or 3,4,5-trichloro-phenyl a-fluoroacrylate,
2,4,6-tribromophenyl a-fluoroacrylate, 2,4,6-triiodophenyl
-fluoroacrylate, 2,3,5,6-tetrafluorophenyl a-fluoro-
acrylate, 2,3,4,5-tetrachlorophenyl a-fluoroacrylate,
2,3,5,6-tetrachlorophenyl a-fluoroacrylate, pentafluoro-
phenyl a-fluoroacrylate, pentachlorophenyl a-fluoroacrylate,
pentabromophenyl a-fluoroacrylate, Z,6-diiodo-4-trifluoro-
methylphenyl a-fluoroacrylate, 2- or 3- or 4-trifluoro-
methylphenyl a-fluoroacrylate, 2-(heptafluoro-2-propyl)-
phe~nyl or 4-~heptafluoro-2-propyl)-phenyl a-fluoroacrylate,
2,6- or 3,5-bis(tr;fluoromethyl)-phenyl a-fluoroacrylate,
`25 4-cyanophenyl ~-fluoroacrylate, 2,6-dibromo-4-cyanophenyl
a-fluoroacrylate, 2,6-d;chloro-4-cyanophenyl a-fluoro-
acrylate, 2,6-difluoro-4-cyanophenyl a-fluoroacrylate,
4-cyano-2,3,5,6-tetrafluorophenyl a-fluoroacrylate, 4-
chloro-2,5- ~or 3,5)-difluorophenyl a-fluoroacrylate, 2-
30~ chloro-4,5- (or 4,6)-difluorophenyl a-fluoroacrylate, 2,5-
~or 2,6- or 3,5-dichloro-4-fluorophenyl a-fluoroacrylate,
2,6- or 3,4-dibromo-3,4 ~or 2,6)-dichlorophenyl a-fluoro-
acrylate, 2,4,6-trichloro-3-fluorophenyl a-fluoroacrylate,
2,4- or 2~6-dichloro-3-trifluoromethylphenyl ~-fluoro-
acrylate, 2,6-d;bromo-4- ~or 5) -trifluoromethylphenyl ~-
~: -fluoroacrylate, 2,4-dibromo-5- ~or 6)-trifluoromethylphenyl
a-fluoroacrylate, 2- or 4-bromo-3-: ~or 5)-trifluoromethyl-
phenyl -fluoroacrylate, 2,3,6-tribromo,4,5-bisbromo-
methylphenyl a-fluoroacrylate, 2,4,5-tribromo-3,6-bis-
:
.
1 309 1 06
-- 8
(bromomethyl)phenyl ~-fluoroacrylate, 2,4,6-trichloro-
3,5-bistchloromethyl)phenyl) ~-fluoroacrylate, 3,4,5-
trichloro-2,~-bistchloromethyl)phenyl ~-fluoroacrylate,
2,4,6-trichloro-3-chloromethylphenyl ~-fluoroacrylate,
5 2,4-d;bromo-6-dibromomethylphenyl -fluoroacrylate, 2,6-
dibromo-4-dibromomethylphenyl a-fluoroacrylate, 2,3,5,6-
tetrachloro-4-chloromethylphenyl ~-fluoroacrylate, 2- or
3-fluoro-4-methylphenyl ~-fluoroacrylate, 3- or 4- or 5-
fluoro-2-methylphenyl ~-fluoroacrylate, 2-fluoro-6-
10 methylphenyl ~-fluoroacrylater 4-fluoro-3-methylphenyl
~-fluoroacrylate, 2,4,6-trichloro 3,5-dimethylphenyl ~-
fluoroacrylate, 2,6-dichloro-3,5-dimethylphenyl ~-fluoro-
acrylate, 2,6-dichloro-4-methylphenyl -fluoracrylate~
2,4,6-tribromo-3,5-d;methylphenyl ~-fluoroacrylate, 2,4,6-
tribromo-3-methylphenyl ~-fluoroacrylate, 2,3,5,6-tetra-
fluoro-4-cyanophenyl -fluoracrylate, 2- or 3- or 4-
methylphenyl ~-fluoroacrylate, 2,3- or 2,4- or 2,5- or
Z,6- or 3,4- or 3,5-dimethylphenyl -fluoroacrylate,
2,4,6-tr;methylphenyl -fluoroacrylate, 2,3,5,6-tetra-
methylphenyl -fluoroacrylate, 2- or 3- or 4-isopropyl-
phenyl -fluoroacrylate, 4-isopropyl-3,5-dimethylphenyl
~-fluoroacrylate and 2,3- or 2,5- or 2,6- or 3,4- or 3,5-
di;sopropylphenyl ~fluoroacrylate~
The subst;tuted phenyl esters of ~-fluoroacrylic ac;d
are colorless liquids or colorless solids at room tem-
perature. They are readily polymerizable and are suitable
for the preparation of crystal clear, light-transmissive,
colorless polymers.
The following examp(es serve to illustrate the invention
;n greater detail. Percentages relate ;n each case to
weight.
Example 1
--.
a) 48 g (0.48 mol) of potassium bicarbonate were dissolved
in 535 9 ~6.59 mol) of aqueous formaldehyde solution
~37% strength by we;ght) ;n a 4-litre glass flask.
~ 1 30q 1 Oh
841 9 (5.6 mol) of dimethyl a-fluoromalonate 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 25C. Stir-
r;ng was continued for 2 hours at the same temperature,
and during this time dimethyl a-hydroxymethyl-~-fluoro-
malonate was precipitated in the form of a colorless
solid. 2,500 9 of an aqueous, saturated solution of
ammonium sulfate were then added to the reaction mix-
ture, 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 dichloride
by distillation (bath temperature 40C, 25 mbar).
b) 175 9 (0.97 mol) of dimethyl a-hydroxymethyl-~-fluoro-
malonate, 750 ml of water and 750 ml of hydrochloric
acid ~36% strength by we;ght) were heated at the boil
for 2 1/2 hours ;n a 2-l;tre glass flask equipped with
a thermometer and stirrer and a Vigreux column fitted
with a dist;llat;on head. The temperature of the
reaction mixture was 103C. The react;on 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 solu-
tion was dried by means of anhydrous sod;um sulfate.
17 9 (1 mol) of gaseous ammonia were then passed into
the solution at room temperature. The colorless pre-
cipitate obtained thereby was filtered off, washed
with diethyl ether and dried at room temperature under
reduced pressure. 70.8 9 t68% of theory) of ammonium
a-fluoroacrylate were obtainedO
:
i 35 c~ 100 g (0.~34 mol) of ammon~ium a-fluoroacrylate were
dispersed in a m;xture of 600 g of mesitylene and
15 ml of dimethylformamide in a 1-li`tre glass flask
and 119 9 (1.0 mol) of thionyl chloride were added in
the course of one hour. The resulting m;xture was heated
---` 1 30q 1 06
- 10 -
to a temperature of 80C and was kept at this temperature
for 2 hours, with stirring. The liquid obtained after
the mixture had coo(ed to room temperature was distilled
under reduced pressure, and the fraction obtained up to
100C/160 mbar was distilled again under normal pressure~
67 g (66% of theory) of ~-fluoroacryloyl chloride were
obtained, boiling point 65 to 67C.
d) A solution of 1119 (0.5 mol) of potassium pentafluoro-
phenate in 250 ml of anhydrous acetonitrile was added
dropwise, in the course of 1 hour, at a temperature
of 25C and with stirring, to a solution of 54.5 9
(0.502 mol) of ~-fluoroacryloyl chloride in 1nO ml of
anhydrous acetone nitrile, and the reaction mixture
was then stirred for a further 2 hours at the same
temperature. The solid formed was filtered off and
washed with 100 ml of anhydrous acetonitrile. The
mixture of filtrate and wash solution was distilled,
after adding 0.01 g of hydroquinone monomethyl ether.
107.1 g (84% of theory) of penafluorophenyl ~-fluoro-
acrylate were obtained, boiling point 41 to 42C
~under 2 mbar).
Example 2
13.9 g ~O~lZ8 mol) of a-fluoroacryloyl chloride (obtained
in accordance with example 1c) were added dropwise, at a
temperature of 25C, with stirring and in the course o~ 30
m;nutes, to a solution of 30 g (0.0985 mol) of potassium
pentachlorophenate in 4ûO ml of anhydrous acetonitrile,
and the react;on m;xture was then st;rred for a further
90 m;nutes at the same temperature. The sol;d formed
was f;ltered off and washed w;th 20 ml of anhydrous aceto-
n;tr;le. After 0.01 g of hydroqu;none monomethyl ether had
been added, the volatile constituents in the m;xture of
filtrat and washing liquor were distilled off
and the residue was recrystallized from boiling n-hexane.
17 g (51% of theory) of pentachlorophenyl ~-fluoroacrylate
were obtained, meltlng polnt 90 to 92C.
: '
1 3nql 06
- 11 -
Example 3
49 g (0.181 mol) of 2,6-dibromo-4-fluorophenol were dis-
solved in 150 ml of anhydrous methylene dichloride, and
1~.3 g (0.181 mol) of triethylamine were added to the
solution; 20 g (0.184 mol) of ~-fluoroacryloyl chloride
(obtained in accordance with example 1c) were then added
dropwise at a temperature of 5C, with stirring and 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 filtered off and washed with 30 ml
of methylene dichloride. The mixture of filtrate and
~ash solution was distilled, after adding 0.01 9 of
hydroquinone monomethyl ether. 46 9 (74% of theory) of
2,6 dibromo-4-fluorophenyl ~-fluoroacrylate were obtained,
- boiling point 86 to 88C (under 0.4 mbar).
Example 4
2.2 9 (0~02 mol) of ~-fluoroacryloyl chloride (obtained
in accordance with example 1c) were added dropwise, at
a temperature of 5C, with stirring and in the course
of 5 minutes, to a solution of 7.8 g (0.019 mol) of 2,6-
diiodo-4-trifluoromethylphenyl and 2 g (0.02 mol) of
triethylamine in 80 ml of anhydrous methylene dichloride,
and the reaction m;xture was then stirred for a further
30 minutes at the same temperature. The solid formed
~as filtered off and washed with 1û ml of anhydrous
methylene dichloride. After 0~001 g of hydroquinone
monomethyl ether had been added, the volatile constituents
in the mixture of filtrate and wash solution were removed
by distillation, and the residue was recrystaLl;zed from
boiling in-hexane. 7 g (76~ of theory) of 2,6-diiodo-4-
trifluoromethylphenyl ~-fluoroacrylate were obtained, melting
point 93 to 95C.
Exam~le 5
16.2 9 (0.1 mol) of 4-trifluoromethylphenol were dissolved
1 309 1 06
,
- 12 -
in 80 ml of anhydrous diethyl ether, and 10.1 9 (0.1 mol)
of triethylamine were added in portions to the solut;on;
12 g (0.11 mol) of o~-fluoroacryloyl chloride (obtained in
accordance with example 1c) were then added dropw;se,
at a temperature of 10C, 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 sol-
ution was distilled, after adding 0.005 9 of hydroquinonemonomethyl ether. 19.5 9 (83~ of theory) of 4-trifluoro-
methylphenyl ~-fluoroacrylate were obtained, boiling
point 69 to 70C (under 3 mbar).
Example 6
27.5 9 (0.169 mol) of 3-trifluoromethylphenol were
dissolved in lOO ml of anhydrous methylene dichloride,
and 17.1 9 (0.169 mol) of triethylamine were added in
portions to the solution; 20 9 tO.184 mol) of ~-fluoro-
acryloyl chloride (obtained in accordance with example 1c)
were then added dropwise, at a temperature of 5C, 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 30 ml of methylene dichlor;de. The mixture
of filtrate and wash solution was distilled, after
adding 0.01 9 of hydroquinone monomethyl ether. 27 g
(68% of theory) of 3-trifluoromethylphenyl ~-fluoro-
acrylate were obtained, boiling point 7~ to 79C (under
- 4 mbar).
Example 7
:
26.2 9 (0.1 mol) of 4-perfluoroisopropylphenol were
dissolved in 100 ml of anhydrous diethyl ether, and
10~1 g (0.1 molj of triethylamine were added to the
solut;on; 12 9 (0.11 mol) of ~-fluoroacryloyl chloride
(obtained in accordance with example 1c) were then added
1 3()ql 06
- 13 -
dropwise, at a temperature of 10C, with stirring and
in the course of 15 minutes, and the reaction mixture
was stirred for a further 30 minutes at the same temper-
ature. The solid formed was filtered off and washed w;th
2û ml of diethyl ether. The mixture of filtrate and wash
solution was distil~ed, after adding 0.005 g of hydro-
quinone monomethyl ether. 22.9 g (69% of theory) of
4-perfluoroisopropylphenyl a-fluoroacrylate were obtained,
boiling point 65 to 66C (under 1 mbar).
Example 8
10 g (0.038 mol) of 2-perflùoroisopropylphenol were
dissolved in 30 ml of anhydrous diethyl ether, and 3.9 g
(0.038 mol) of triethylamine were added to the solution;
4.3 g (0.039 mol) of ~-fluoroacryloyl chloride (obtained
in accordance with example 1c) were then added dropwise,
at a temperature of 10C, 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 ml
of diethyl ether. The mixture of filtrate and wash sol-
ut;on was d;stilled after adding 0.002 g of hydroquinone
monomethyl ether. 7 9 ~55~ of theory) of 2-perfluoro-
isopropylphenyl a-fluoroacrylate were obtained, boiling
point 85C (under 1 mbar).
Example 9
10 9 (0.092 mol) of a-fluoroacryloyl chloride (obtained in
accordance with example 1c) were added drop~ise, at a
temperature of 5C, with stirring and in the course of
20 minutes, to a solution of 10~7 g (0.09 mol) of 4-cyano-
phenol and 9.1 g (0.09 mol) of triethylamine in 150 ml
of anhydrous methylene dichloride, and the reaction
mixture was then stirred for a further 30 minutes at the
same temperatureu The solid formed was filtered off and
washed with Z0 ml of anhydrous methylene dichloride.
After 0.005 9 of hydroquinone monometbyl ether had been
.:
~ 3~39 1 0 6
- 14 -
added, the volatiLe constituents in the mixture of
filtrate and wash solution were removed by distillation,
and the residue was recrystallized from boiling n-hexane.
11.2 9 (65% of theory) of 4-cyanophenyl ~-fluoroacrylate
were obtained, melting point 78 to 79C.
Example 10
10 g (0.092 mol) of ~-fluoroacryloyl chloride (obtained in
accordance with example 1c) were added dropwise, at a
temperature of 5C, with stirring and in the course of
20 minutes, to a solution of 16.7 g (0.089 mol) of 3,5-
dichloro-4-hydro~ybenzonitrile and 9 9 (0.089 mol) of
triethylamine in Z00 ml of anhydrous methylene 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 9 of hydroquinone monomethyl
ether had been added, the volatile constituents in the
mixture of filtrate and wash solution were removed by
distillat;on, and the residue was recrystallized from
boiling n-heptane. 18.7 9 ~81% of theory) of 2,6-
dichloro-4-cyanophenyl ~-fluoroacrylate were obtained,
melting point 95 to 99C.
ZS
Example 11
10 g (0.092 mol) ~-fluoroacryloyl chloride (obtained ;n
accordance with example 1c) were added dropwise, at a
temperature of 5C, with stirring and in the course of
S minutes, to a solution of 24.~ 9 (0.09 mol) of 3,5-
dibromo-4-hydroxybenzonitrile and 9.1 9 tO.09 mol) of
triethylamine in 200 ml of anhydrous methyLene dichloride,
and the reaction mixture was then stirred for a further
~5 30 minutes at the same temperature. The solid formed was
filtered off and washed w;th 29 ml of anhydrous methylene
dichloride. After O.OOS g of hydroquinone monomethyl
ether had been added, the volatile constituents in the
mixture of fiLtrate and ~ash s~lut1on were removed by
':~
.,
``" - 1 309 1 06
- 15 -
distillation, and the residue was recrystallized from
boiling n-heptane~ 17~5 9 (55% of theory) of 2,6-dibromo-
4-cyanophenyl ~-fluoroacrylate were obtained, melting
point 135 to 138C.
:
~: :
