Bifunctional stilbene compounds containing at least one Z-configurated stilbene group, process for their preparation and their use for the preparation of polymers

New Z-stilbene compounds and a process for their preparation are disclosed wherein the compounds correspond to the following formulae: ##STR1##

This invention relates to a process for the preparation of bifunctional 
Z-stilbene compounds, to new bifunctional Z-stilbene compounds and to the 
use of the Z-stilbene compounds for the preparation of polymers. 
Z(cis)-stilbenes may be prepared by, for example, subjecting aryl aldehydes 
and aryl acetic acids to a Perkin condensation and decarboxylating the 
resulting cis-.alpha.,.beta.-diarylacrylic acids in quinoline in the 
presence of copper chromite at temperatures of about 200.degree. C. (see 
F. Merger in Houben-Weyl, Vol. V/1b, page 308). This process does not 
always give rise to pure Z-stilbenes but to products containing a certain 
amount of the corresponding E(trans) stilbenes, the removal of which 
requires an elaborate procedure of chromatography or crystallisation and 
is not always complete. Another disadvantage of the process lies in the 
high temperatures (about 200.degree. C.) required for decarboxylation, 
which may give rise to side reactions. The yields are only moderate and 
the range of variation of the reaction sequence is small due to the fact 
that some substituted aryl halides and aryl acetic acids are difficultly 
obtainable. 
The synthesis of alkyl substituted Z-stilbenes is described by E. B. 
Merkushev and T. S. Skorokhodova in Zhurnal Organicheskoi Khimii, Vol. 18, 
No. 2, pages 355-359. The starting materials used for this synthesis are 
alkyl iodobenzenes which react with acetylene in the presence of Pd 
catalysts to yield di(alkylaryl)acetylenes which are subsequently stereo 
specifically hydrogenated to Z-stilbenes. 
One disadvantage of this process is the use of the expensive and 
difficultly obtainable aryl iodides. The reaction has only been described 
for iodobenzene or alkyl substituted iodobenzenes and is on the whole 
suitable only for the preparation of the corresponding symmetric dialkyl 
substituted Z-stilbenes. 
A process has now been found for the preparation of bifunctional stilbene 
compounds containing at least one Z-configurated stilbene group and 
corresponding to the following formula 
##STR2## 
wherein Z and Y may be identical or different and denote COOR, COR, COCl, 
OCOCl, NCO, NRCOCl, NHR, OR or Cl, where R=hydrogen or C.sub.1 -C.sub.8 
-alkyl, 
A and A.sup.1 are identical or different and denote a chemical bond or 
CH.dbd.CH, 
B denotes 
##STR3## 
B.sup.1 denotes 
##STR4## 
l stands for 0 or 1, p and p.sup.1 stand for 0 or 1, 
q and q.sup.1 stand for 0 or 1 and 
n stands for 0, 1 or 2, 
characterised in that compounds corresponding to the following formula 
##STR5## 
wherein A and p have the meaning indicated above, 
D denotes COOR.sup.1, COR.sup.1, NHR.sup.2, NO.sub.2, OR.sup.3, Cl or Br, 
where R.sup.1 =hydrogen or branched or straight chained C.sub.1 -C.sub.8 
-alkyl, R.sup.2 =OAc, COOC.sub.2 H.sub.5 or another suitable protective 
group and R.sup.3 =OAc, 
##STR6## 
or another suitable protective group and X stands for bromine or iodine 
are reacted with an acetylene corresponding to the following formula 
EQU HC.tbd.C-R.sup.4 (III), 
wherein R.sup.4 stands for 
##STR7## 
or Si(R.sup.5).sub.3, where R.sup.5 and R.sup.6 =C.sub.1 -C.sub.4 -alkyl, 
at temperatures from 30.degree. to 160.degree. C. in the presence of a 
palladium catalyst and a base, the resulting compounds are converted in 
the presence of a base into compounds corresponding to the following 
formula 
##STR8## 
wherein D, A and p have the meanings indicated above, and the compounds of 
formula (IV) are then reacted with compounds corresponding to the 
following formula 
##STR9## 
wherein D.sup.1, A.sup.1 and p.sup.1 have the meanings described for A, D 
and p and 
X stands for bromine or iodine 
at temperatures from 30.degree. to 160.degree. C. in the presence of a 
palladium catalyst and a base and the resulting acetylene compounds are 
reduced with hydrogen or another reducing agent in the presence of 
catalysts to form Z-stilbene compounds corresponding to the following 
formula 
##STR10## 
wherein D, D.sup.1, A, A.sup.1 and p and p.sup.1 have the meanings 
indicated above, and the functional groups D and D.sup.1 are converted 
into the above mentioned functional groups Z and Y of formula (I) in known 
manner or when D and D.sup.1 stand for at least one bromine atom, the 
Z-stilbene compounds of formula (VI) are reacted with compounds 
corresponding to the following formula 
EQU H.sub.2 C.dbd.CHR.sup.7 (VII) 
wherein 
R.sup.7 stands for hydrogen or 
##STR11## 
where D.sup.2 has the meaning given above for D.sup.1 at temperatures from 
30.degree. to 160.degree. C. in the presence of a palladium catalyst and a 
base, and the functional groups D, D.sup.1 and D.sup.2 are converted into 
the functional groups Z and Y of formula (I) in the usual manner or the 
compounds of formula (IV) are reacted with compounds corresponding to the 
following formula 
##STR12## 
wherein A.sup.1 X and p.sup.1 have the meanings indicated above and 
X.sup.1 stands for bromine or iodine 
at temperatures from 30.degree. to 160.degree. C. in the presence of a 
palladium catalyst and a base and the resulting acetylene compounds are 
then reduced to the corresponding Z-stilbene compounds with hydrogen or 
other reducing agents in the presence of catalysts and the functional 
groups D are then converted into functional groups Z and Y of formula (I) 
in known manner. 
The reaction of the aromatic halides of the general formula II with 
acetylenes of formula (III) may be carried out by a method which is 
already known in principle (see e.g. A. Segnitz in Houben-Weyl Vol. 13/9b, 
pages 987 et seq). According to this method, the reaction is carried out 
in the presence of a palladium catalyst and the compound which is basic in 
reaction, optionally in the presence of a cocatalyst, a phosphane and a 
solvent and/or diluent at temperatures of about 30.degree. to 160.degree. 
C., preferably from 40.degree. to 130.degree. C. 
This reaction gives rise to compounds corresponding to the following 
general formula (IX) 
##STR13## 
wherein D, A, p and R.sup.4 have the meanings indicated above. 
Examples of preferred aromatic halides of formula (II) include those in 
which A stands for a chemical bond or CH.dbd.CH, X stands for bromine or 
iodine, p stands for 0 or 1 and D stands for COOR.sup.1, COR.sup.1, 
NHR.sup.2, NO.sub.2, OR.sup.3, Cl or Br, where R.sup.1 =hydrogen or 
branched or straight chained C.sub.1 -C.sub.8 -alkyl, R.sup.2 =OAc, 
COOC.sub.2 H.sub.5 or another suitable protective group and R.sup.3 =OAc, 
##STR14## 
or another suitable protective group. 
The following are given as examples of aromatic halides corresponding to 
formula (II): 4-Bromobenzoic acid, 4-bromobenzoic acid methyl ester 
4-bromobenzoic acid ethyl ester, 4-bromobenzoic acid-n-propyl ester, 
4-bromobenzoic acid-i-propyl ester, 4-bromobenzoic acid-n-butyl ester, 
4-bromobenzoic acid-i-butyl ester 4-bromobenzoic acid tert.-butyl ester, 
4-bromobenzoic acid-n-pentyl ester, 4-bromonitrobenzene, 
4-bromobenzaldehyde, 4-acetoxybromobenzene, 4-acetoxy iodobenzene, 
4-bromophenyl tetrahydropyranyl ether, 4-iodophenyl tetrahydropyranyl 
ether, 1,4-dibromobenzene, 1-bromo-4-iodobenzene, 4-bromoacetophenone, 
(4-bromophenyl)-ethyl) ketone, (4-bromophenyl)-n-propyl ketone, 
(4-bromophenyl)-i-propyl ketone, (4-bromophenyl)-n-butyl ketone, 
4-bromoacetanilide, 4-iodoacetanilide, 4-bromophenyl carbamic acid ethyl 
ester, 1-bromo-4-chlorobenzene, 1-chloro-4-iodobenzene, 
4-bromobiphenyl-4'-carboxylic acid methyl ester, 
4-bromobiphenyl-4'-carboxylic acid ethyl ester, 
4-bromobiphenyl-4'-carboxylic acid n-propyl ester, 
4-bromobiphenyl-4'-carboxylic acid i-propyl ester, 
4-bromobiphenyl-4'-carboxylic acid n-butyl ester, 
4-bromobiphenyl-4'-carboxylic acid i-butyl ester, 
4-bromobiphenyl-4'-carboxylic acid tert.-butyl ester, 4-bromobiphenyl- 
4'-carboxylic acid-n-pentyl ester, 4-bromo-4'-nitrobiphenyl, 
4-acetoxy-4'-bromobiphenyl, 4-bromobiphenyl-4'-tetrahydropyranyl ether, 
4-bromo-4'-iodobiphenyl, 4,4'-dibromobiphenyl, 4-bromo-4'-chlorobiphenyl, 
(4-bromobiphenyl-4'-yl)-methyl ketone, (4-bromobiphenyl-4'-yl)-ethyl 
ketone, (4-bromobiphenyl-4'-yl)-n-propyl ketone 
(4-bromobiphenyl-4'-yl)-i-propyl ketone, (4-bromobiphenyl-4'-yl)-n-butyl 
ketone, 4-acetamino-4'-bromobiphenyl, 4-bromobiphenyl-4'-carbamic acid 
ethyl ester, 4-bromostilbene-4'-carboxylic acid methyl ester, 
4-bromostilbene-4'-carboxylic acid ethyl ester, 
4-bromostilbene-4'-carboxylic acid n-propyl ester, 
4-bromostilbene-4'-carboxylic acid n-butyl ester, 
4-bromostilbene-4'-carboxylic acid i-propyl ester, 
4-bromostilbene-4'-carboxylic acid i-butyl ester, 
4-bromostilbene-4'-carboxylic acid tert.-butyl ester, 
4-bromostilbene-4'-carboxylic acid n-pentyl ester, 
4-bromo-4'-nitrostilbene, 4-acetoxy-4'-bromostilbene, 
4-bromostilbene-4'-tetrahydropyranyl ether, 4-bromo-4'-iodostilbene, 
4,4'-dibromostilbene, 4-bromo-4'-chlorostilbene, 
(4-bromostilbenyl-4')-methyl ketone, (4-bromostilbenyl-4')-ethyl ketone, 
(4-bromostilbenyl-4')-n-propyl ketone, (4-bromostilbenyl-4') i-propyl 
ketone, (4-bromostilbenyl-4')-n-butyl ketone, 4-acetamino-4'-bromostilbene 
and 4-bromostilbene-4'-carbamic acid ethyl ester, preferably 
4-bromobenzoic acid, 4-bromobenzoic acid methyl ester, 4-bromobenzoic acid 
ethyl ester, 4-bromobenzoic acid n-propyl ester, 4-bromobenzoic acid 
i-propyl ester, 4-bromobenzoic acid n-butyl ester, 4-bromobenzoic acid 
i-butyl ester, 4-bromobenzoic acid tert.-butyl ester, 4-bromonitrobenzene, 
4-bromobenzaldehyde, 4-acetoxybromobenzene, 4-acetoxyiodobenzene, 
4-bromophenyl tetrahydropyranyl ether, 4-iodophenyl tetrahydropyranyl 
ether, 1,4-dibromobenzene, 1-bromo-4-iodobenzene, 4-bromoacetophenone, 
(4-bromophenyl)ethyl ketone, (4-bromophenyl)-n-propyl ketone, 
4-bromoacetanilide, 4-iodoacetanilide, 4-bromophenyl carbamic acid ethyl 
ester, 1-bromo-4-chlorobenzene, 4-bromobiphenyl-4'-carboxylic acid methyl 
ester, 4-bromobiphenyl-4'-carboxylic acid ethyl ester, 
4-bromobiphenyl-4'-carboxylic acid n-propyl ester, 
4-bromobiphenyl-4'-carboxylic acid i-propyl ester, 
4-bromobiphenyl-4'-carboxylic acid n-butyl ester, 
4-bromobiphenyl-4'-carboxylic acid i-butyl ester, 
4-bromobiphenyl-4'-carboxylic acid tert.-butyl ester, 
4-bromo-4'-nitrobiphenyl, 4-acetoxy-4'-bromobiphenyl, 
4-bromo-4'-iodobiphenyl, 4,4'-dibromobiphenyl, 4-bromo-4'-chlorobiphenyl, 
(4-bromobiphenyl-4'-yl)-methyl ketone, (4-bromophenyl-4'-yl)-ethyl ketone 
(4-bromobiphenyl-4'-yl)-n-propyl ketone, 4-bromobiphenyl-4'-carbamic acid 
ethyl ester, 4 bromostilbene-4'-carboxylic acid methyl ester, 
4-bromostilbene-4'-carboxylic acid ethyl ester, 
4-bromostilbene-4'-carboxylic acid n-propyl ester, 
4-bromostilbene-4'-carboxylic acid n-butyl ester, 
4-bromostilbene-4'-carboxylic acid i-propyl ester, 
4-bromostilbene-4'-carboxylic acid i-butyl ester, 
4-bromostilbene-4'-carboxylic acid tert.-butyl ester, 
4-bromo-4'-nitrostilbene, 4-acetoxy-4'-bromostilbene, 
4-bromostilbene-4'-tetrahydropyranyl ether, 4-bromo-4'-iodostilbene, 
4,4'-dibromostilbene, 4-bromo-4'-chlorostilbene, 
(4-bromostilbenyl-4')-methyl ketone, (4-bromostilbenyl-4')-ethyl ketone, 
(4-bromostilbenyl-4')-n-propyl ketone and 4-bromostilbene-4'-carbamic acid 
ethyl ester. The following are particularly preferred: 4-Bromobenzoic 
acid, 4-bromobenzoic acid methyl ester, 4-bromobenzoic acid ethyl ester, 
4-bromobenzoic acid n-butyl ester, 4-bromobenzoic acid tert.-butyl ester, 
4-bromonitrobenzene, 4-acetoxybromophenol, 4-bromophenyl-tetrahydropyranyl 
ether, 4-iodophenyl-tetrahydropyranyl ether, 1,4-dibromobenzene, 
1-bromo-4-iodobenzene, 4-bromoacetophenone, (4-bromophenyl)ethyl ketone, 
4-bromoacetanilide, 4-bromophenylcarbamic acid ethyl ester, 
1-bromo-4-chlorobenzene, 4-bromobiphenyl-4'-carboxylic acid methyl ester, 
4-bromobiphenyl-4'-carboxylic acid ethyl ester, 
4-bromobiphenyl-4-carboxylic acid n-butyl ester, 
4-bromobiphenyl-4'-carboxylic acid tert.-butyl ester, 
4-bromo-4'-nitrobiphenyl, 4-acetoxy-4'-bromobiphenyl, 
4-bromo-4'-iodobiphenyl, 4,4'-dibromobiphenyl, 4-bromo-4'-chlorobiphenyl, 
(4-bromobiphenyl-4'-yl)-methyl ketone, (4-bromobiphenyl-4'-yl)-ethyl 
ketone, (4-bromobiphenyl-4'-yl)-n-propyl ketone, 
4-bromobiphenyl-4'-carbamic acid ethyl ester, 
4-bromostilbene-4'-carboxylic acid ethyl ester, 
4-bromostilbene-4-carboxylic acid n-propyl ester, 
4-bromostilbene-4'-carboxylic acid tert.-butyl ester, 
4-bromo-4'-nitrostilbene, 4-acetoxy-4'-bromostilbene, 
4-bromostilbene-4'-tetrahydropyranyl ether, 4-bromo-4'-iodostilbene 
4,4'-dibromostilbene 4-bromo-4'-chlorostilbene, 
(4-bromostilbenyl-4'-methyl ketone, (4-bromostilbenyl-4')-ethyl ketone, 
(4-bromostilbenyl,4')-n-propyl ketone and 4-bromostilbene-4'-carbamic acid 
ethyl ester. 
Preferred compounds of formula (III) are those in which R.sup.5 and R.sup.6 
stand for methyl or ethyl, e.g. 2-methyl-3-butyne-2-ol and 
trimethylsilylacetylene. 
In the process according to the invention, about 0.8 to 1.2 mol preferably 
1.0 to 1.2 mol of compound (III) is used per mol of compound of formula 
(II). Suitable palladium catalysts are described e.g. in R. F. Heck, 
Palladium Reagents in Organic Syntheses, Academic Press, New York 1985. 
Chapter 6, Section 6.8.1). The following are examples of suitable 
palladium catalysts: Pd(OAc).sub.2, PdCl.sub.2 (P.phi..sub.3).sub.2, 
Pd(OAc).sub.2 (P.phi..sub.3).sub.2, Pd(P.phi..sub.3).sub.4 and/or 
PdCl.sub.2, used in a quantity of about 0.005 to 10 mol-%, preferably 0.05 
to 5 mol-%, based on the aryl halide of formula (II) (.phi. denotes 
phenyl). 
The compound which is basic in reaction may be used in excess in order to 
bind the hydrogen halide released in the reaction. The compound which is 
basic in reaction may also be used as diluent. Suitable compounds which 
are basic in reaction include, for example, secondary and/or tertiary 
amines such as diethylamine, diisopropylamine, piperidine, triethylamine, 
pyridine and N,N'-diethylaniline, salts of carboxylic acids such as 
potassium acetate, alkali metal carbonates such as potassium carbonate, 
alkali metal bicarbonates such as sodium bicarbonate, alkali metal 
alcoholates such as sodium methanolate and sodium ethanolate and alkali 
metal hydrides such as sodium hydride. 
Copper(I) iodide, for example, may be used as cocatalyst for the reaction 
of compound (II) with compound (III). This cocatalyst may be added in a 
quantity of about 10 to 1000 mol-%, based on the quantity of palladium 
used. The activity of the catalyst may be further improved by the addition 
of phosphanes. Preferred phosphanes are, for example, triphenylphosphane 
and tri-o-tolylphosphane. The quantity of phosphanes to be used may easily 
be determined by preliminary tests. They are generally used in a quantity 
of about 100 to 1000 mol-%, based on the palladium put into the process. 
It is in some cases advantageous to carry out the reaction according to the 
invention of compounds of formula (II) with compounds of formula (III) in 
the presence of a solvent and/or diluent. The following are examples of 
suitable solvents and diluents: Aromatic hydrocarbons such as benzene, 
toluene or xylene, ethers such as tetrahydrofuran or dioxane, alcohols 
such as methanol or ethanol, acetonitrile, dimethylsulphoxide, 
dimethylformamide and N-methylpyrrolidone as well as amines such as 
diethylamine or triethylamine. The solvents and/or diluents may be used 
singly or as mixtures. The quantity may vary within a wide range and a 
suitable quantity may easily be determined by preliminary tests. 
It is sometimes also advantageous to carry out the reaction in an inert gas 
atmosphere, e.g. a nitrogen atmosphere. This depends, for example, on the 
starting materials used. 
The compounds of formula (IX) obtained by the reaction of compounds of 
formula (II) with compounds of formula (III) are converted into acetylenes 
of the general formula (IV) by a treatment with compounds which are basic 
in reaction, optionally in suitable solvents and/or diluents. In this 
reaction, the group R.sup.4 of the compounds of formula (IX) is replaced 
by hydrogen. Methods for such reactions have been described, e.g. by 
V.Jager in Houben-Weyl, Vol. V/2a, pages 405 and 649. 
The compounds which are basic in reaction may be, for example, alkali metal 
hydroxides such as sodium hydroxide and/or potassium hydroxide, alkali 
metal carbonates such as sodium carbonate and/or potassium carbonate and 
alkali metal hydrides such as sodium hydride. The quantity of basically 
reacting compounds to be used may easily be determined by preliminary 
tests and is normally from 1 to 100 mol-% preferably from 3 to 50 mol-%, 
based on the quantity of compound (IX) put into the process. 
The following are examples of suitable solvents and/or diluents for the 
reaction described above: Aromatic hydrocarbons such as benzene, toluene 
or xylene, alcohols such as methanol or ethanol and mixtures of the 
above-mentioned solvents and/or diluents. 
The reaction temperatures for the above-mentioned reaction depend to a 
large extent on the individual case. If the reaction is carried out in a 
solvent and/or diluent, the temperatures employed would generally be from 
-20.degree. C. to the boiling point of the solvent and/or diluent or 
mixtures used. 
If R.sup.4 in formula (IX) stands for C(CH.sub.3).sub.2 --OH, the acetone 
formed in the above described reaction may be continuously distilled off. 
If R.sup.4 in formula (IX) stands for Si(CH.sub.3).sub.3, the protective 
group may also be replaced by hydrogen by means of a treatment with 
potassium fluoride dihydrate or potassium fluoride in a suitable solvent 
and/or diluent such as methanol, ethanol and/or dimethylformamide. 
In the process according to the invention, the compounds of formula (IV) 
are reacted with compounds of formula (V) at temperatures from 30.degree. 
to 160.degree. C., preferably at 40.degree. to 130.degree. C., optionally 
in an inert gas atmosphere, in the presence of a palladium catalyst and a 
compound which is basic in reaction, optionally in the presence of a 
cocatalyst, optionally a phosphane, and optionally in the presence of a 
solvent and/or diluent. This reaction gives rise to diarylacetylenes 
corresponding to formula (X) 
##STR15## 
wherein D, D.sup.1, A, A.sup.1, p and p.sup.1 have the meanings indicated 
above. 
In the reaction of compounds of formula (IV) with the aromatic halides of 
formula (V) to form the diarylacetylenes of formula (X), from 0.7 to 1.3 
mol, preferably from 0.8 to 1.2 mol of the compound of formula (IV) is 
generally used per mol of compound (V). 
In the process according to the invention the compounds of formula (IV) may 
also be reacted with aromatic dihalides corresponding to the general 
formula (VIII) 
##STR16## 
wherein X.sup.1 and X and A.sup.1 and p.sup.1 have the meanings indicated 
above to form diacetylene compounds corresponding to formula (XI) 
##STR17## 
wherein D, A, A.sup.1, p and p.sup.1 have the meanings indicated above. 
In that case, the compound of formula (IV) is generally used in a quantity 
of about 2.0 to 2.6 mol, preferably 2.0 to 2.2 mol, per mol of the 
compound of formula (VIII). 
The reaction is again carried out at temperatures from 30.degree. to 
160.degree. C. in the presence of a palladium catalyst and a compound 
which is basic in reaction, as described above. 
The following are examples of preferred compounds of formula (VIII): 
1,4-Diiodobenzene, 1-bromo-4-iodobenzene, 1,4-dibromobenzene, 
4,4'-diiodobiphenyl, 4-bromo-4'-iodobiphenyl, 4,4'-dibromobiphenyl, 
4,4'-diiodostilbene, 4-bromo-4'-iodostilbene and 4,4'-dibromostilbene, the 
following being particularly preferred: 1,4-dibromobenzene, 
4,4'-dibromobiphenyl and 4,4'-dibromostilbene. 
As regards the palladium catalyst, the base, the cocatalyst and the 
addition of phosphane and diluent or solvent, the same applies as already 
described for the reaction of compounds of formula (II) with compounds of 
formula (III). 
The acetylenes of formula (X) obtained from the reaction and the 
diacetylenes of formula (XI) obtained are then reduced to the 
corresponding Z-stilbene compounds by means of hydrogen or other suitable 
reducing agents in the presence of catalysts. These Z-stilbene compounds 
are compounds corresponding to formula (VI): 
##STR18## 
wherein D, A, A.sup.1, p and p.sup.1 have the meanings already indicated 
and compounds corresponding to formula (XII) 
##STR19## 
wherein D, A, A.sup.1, p and p.sup.1 have the meanings already indicated. 
The following are examples of suitable reduction processes: Hydrogenation 
in the presence of hydrogenation catalysts such as special palladium or 
nickel catalysts which have been described, for example, by H. Balli in 
Houben-Weyl, Vol. V/1b, pages 588 et seq; by H. Gutmann and H. Lindlar in 
Chemistry of Acetylenes, H. G. Viehe Ed., Marcel Dekker, New York 1969, 
pages 355 et seq; and by J. J. Brunet and P. Caubere in J.Org.Chem. 49, 
4058 (1984); reduction with systems of metal and agents which split off 
protons, such as the reduction with zinc or zinc/copper pairs in acetic 
acid, alcohol or water (described e.g. by H. Balli in Houben-Weyl, Vol. 
V/1b, page 583; by B. L. Sondengam, G. Charles, and T. H. Akam, in 
Tetrahedron Lett. 1069 (1980); and by M. H. P. J. Aerssens, and L. 
Brandsma in J.Chem.Soc.Chem.Commun. 735 (1984); the conversion of 
acetylenes into vinyl silanes followed by stereoselective exchange of the 
silyl group for hydrogen (see e.g. D. G. Batt, and B. Ganem, in 
Tetrahedron Lett. 3323 (1978)) and the monohydroborination of acetylenes 
followed by protolysis, reduction with dialkyl aluminium hydrides or 
reduction with diimine (see H. Balli in Houben-Weyl, Vol. V/1b, pages 583 
et seq). 
When D and D.sup.1 stand for at least one bromine atom, the compounds of 
formula (VI) may be reacted by the process according to the invention with 
compounds of formula (VII) in the presence of a palladium catalyst and a 
compound which is basic in reaction, optionally in the presence of a 
cocatalyst, optionally in the presence of a phosphane and optionally in 
the presence of a solvent and/or diluent at temperatures from 30.degree. 
to 160.degree. C., preferably at 40.degree. to 130.degree. C., optionally 
in an inert gas atmosphere, to produce compounds corresponding to the 
general formulae (XIII), (XIV) and (XV) in which D, A, p, A.sup.1, p.sup.1 
and D.sup.1 and D.sup.2 have the meanings already indicated: 
##STR20## 
The reaction of aromatic halides, in particular aromatic bromides and 
iodides, with ethylene or ethylene derivatives is a known reaction (see 
e.g. R. F. Heck, Org. React. 27, 345 (1982)) and is carried out in the 
present invention by the conventional method. 
The compounds corresponding to formula (VII) are well known compounds of 
organic chemistry or may easily be prepared by analogous processes (see 
e.g. W. Heitz et al, Makromol. Chem. 189, 119 (1988)). 
The following are examples of preferred compounds corresponding to formula 
(VII): 4-Carboxystyrene, 4-carbomethoxystyrene, 4-carboethoxystyrene, 
4-carbo-n-propoxystyrene, 4-carbo-i-propoxystyrene, 
4-carbo-n-butoxystyrene, 4-carbo-i-butoxystyrene, 
4-carbo-tert.-butoxystyrene, 4-acetaminostyrene, 4-acetoxystyrene, 
4-nitrostyrene, (styry-4)methyl ketone, (styryl-4)ethyl ketone, 
(styryl-4)-n-propyl ketone, (styryl-4)-i-propyl ketone, (styryl-4)-n-butyl 
ketone, 4-chlorostyrene and 4-aminostyrene. 
As a final step of the process according to the invention, the resulting 
Z-stilbene compounds containing the functional groups D, D.sup.1 and 
D.sup.2 are converted by basically known methods into the bifunctional 
stilbene compounds of formula (I) claimed according to the invention, 
which contain the functional groups Y and Z and have at least one 
Z-configurated stilbene group. 
The conversion of the functional groups may be carried out, for example, by 
acid or alkaline hydrolysis of esters to the corresponding acids, by 
proton catalysed decomposition of tert.-butyl esters into free carboxylic 
acids and isobutene, by conversion of carboxylic acids into their 
chlorides, e.g. by a reaction with thionyl chloride or oxalyl chloride, 
optionally in the presence of catalytic quantities of DMF or pyridine, by 
the oxidation of aryl ketones to the corresponding aryl carboxylic acids, 
by the reduction of nitro groups to amino groups, by the conversion of 
amino or carboxyl groups into isocyanate groups or by the reaction of 
hydroxyl groups into the corresponding chlorocarbonic acid esters. These 
methods are well known and have been described e.g. in "Organikum", by a 
group of co-authors, VEB Deutscher Verlag der Wissenschaften, Berlin 1976; 
J. March, Advanced Organic Chemistry, Wiley, 3rd Ed. 1985; and C. Ferri, 
Reactionen der organischen Synthese, Stuttgart, Thieme 1978. 
The process according to the invention may be represented by the following 
scheme of formulae which illustrates by way of example the synthesis of 
Z-1-(4-carboxyphenyl)-2-(4'-carboxybiphenyl-4-yl)ethene: 
##STR21## 
Reactions e) 2. and 3. serve merely to purify the reaction product. 
In one variation of the process according to the invention, aryl halides of 
formula (II) can be directly converted into the corresponding 
diarylacetylenes of formula (X) in which D=D.sup.1, A=A.sup.1 and 
p=p.sup.1 and the symbols have the meanings already given for formula (X) 
by reacting the aryl halides of formula (II) with acetylenes of formula 
(III) in the presence of a palladium catalyst and a base, optionally in 
the presence of a cocatalyst, a phosphane, a solvent and/or diluent and a 
phase transfer catalyst at temperatures from 40.degree. C. to 170.degree. 
C., preferably at 60.degree. C. to 130.degree. C. 
The aryl halides of formula (II) are preferably of the type given in the 
above list of aryl halides of formula (II). 
The acetyl compound of formula (III) is preferably 2-methyl-3-butyn-2-ol. 
In this variation, from 0.8 to 1.2 mol, preferably from 0.9 to 1.1 mol of 
acetylene of formula (III) are generally used for 2 mol of the aryl halide 
of formula (II). The palladium catalysts used are those already previously 
mentioned. 
The reaction according to this variation is carried out in the presence of 
a compound which is basic in reaction. Examples of suitable compounds 
which are basic in reaction include alkali metal hydroxides such as sodium 
hydroxide and potassium hydroxide, alkali metal alcoholates such as sodium 
ethanolate and sodium methanolate, alkali metal hydrides such as sodium 
hydride, alkali metal amides such as sodamide, alkali metal carbonates 
such as sodium carbonate and potassium carbonate, alkali metal 
bicarbonates such as sodium bicarbonate and potassium bicarbonate, and 
mixtures of these compounds with one another. The reaction according to 
this variation may also be carried out in the presence of an aqueous 
solution of the above mentioned compounds which are basic in reaction. A 
co-catalyst may be used to accelerate the reaction. The co-catalysts 
already mentioned above are suitable for this purpose. Phosphanes may also 
be used for the reaction according to this variation. Suitable phosgenes 
have already been described above. 
The reaction may be carried out in the presence of a solvent and/or diluent 
if necessary. Examples of suitable solvents and/or diluents include 
aromatic hydrocarbons such as benzene, toluene and/or xylene, amides such 
as dimethylformamide and/or NMP and/or sulphoxides such as 
dimethylsulphoxide and alcohols such as methanol and/or ethanol. 
A phase transfer catalyst for the reaction of compounds of formula (II) 
with compounds of formula (III) may also be used in this variation. 
Suitable phase transfer catalysts are described, for example, by E. V. 
Dehmlow, and S. S. Dehmlow in Phase Transfer Catalysis. 2nd Edition, 
Verlag Chemie, Deerfield Beach. Fla., 1983. The following are suitable 
examples: Tetraethylammonium chloride monohydrate, tetraethylammonium 
bromide, tetraethylammonium iodide, tetraethylammonium tetrafluoroborate, 
tetraethylammonium-p-toluene sulphonate, allyl triethylammonium bromide, 
n-hexyl-trimethylammonium bromide, phenyl triethylammonium chloride, 
phenyltrimethylammonium iodide, benzyl trimethylammonium bromide, benzyl 
trimethylammonium iodide, n-octyl-trimethylammonium bromide, 
tetra-n-propylammonium bromide, tetra-n-propylammonium hydrogen sulphate, 
tetra-n-propylammonium trifluoromethanesulphonate, benzyl triethylammonium 
chloride, benzyl triethylammonium bromide, benzyl triethylammonium 
tetrafluoroborate, n-dodecyl trimethylammonium bromide, 
tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, 
tetra-n-butylammonium iodide, tetra-n-butylammonium hydrogen sulpyhate, 
tetra-n-butylphosphonium bromide, tetraphenylphosphonium chloride, 
tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, 
tetraphenylphosphonium hexafluoroantimonate, tetraphenylphosphonium 
tetrafluoroborate, N-hexadecylpyridinium bromide, tetra-n-hexylammonium 
bromide, tetra-n-hexylammonium hydrogen sulphate, 
n-hexadecyl-tri-n-butylphosphonium bromide, 
triphenylmethyl-triphenylphosphonium chloride, tetra-n-octylammonium 
bromide and tetra-n-dodecylammonium iodide. 
It may be advantageous to carry out the reaction in an inert gas 
atmosphere, e.g. a nitrogen atmosphere. 
In this variation, the reaction is generally carried out by introducing the 
aryl halide of formula (II), the acetylene of formula (III), the palladium 
catalyst, optionally the cocatalyst, the phosphane and the phase transfer 
catalyst into the reaction vessel, optionally in a suitable solvent and/or 
diluent, adding the compound which is basic in reaction and heating the 
reaction mixture to a sufficiently high temperature for the reaction. The 
components for the reaction may, of course, also be added in a different 
sequence. The acetylene of formula (III), optionally dissolved in one of 
the above-mentioned solvents and/or diluents, may be added dropwise to the 
other reactants at the reaction temperature within a suitable period of 
time, i.e. within about 0.5 to 24 hours. The progress of the reaction may 
be followed, for example, gas chromatographically. For working up the 
reaction product, the phases are generally separated and the reaction 
product is isolated by conventional methods. The reaction product in some 
cases already precipitates during the reaction or on cooling after 
termination of the reaction, in which case it is separated by suction 
filtration and the liquid phases are worked up by the usual methods. The 
reaction product may be purified by crystallisation, distillation or 
chromatography. 
The reaction sequence of the process carried out according to this 
variation may be represented by the following scheme of formulae which 
illustrates by way of example the synthesis of Z-4,4'-stilbene 
dicarboxylic acid dichloride: 
##STR22## 
Steps h) 2. and 3. shown here serve merely for further purification of the 
reaction product. 
According to another variation, compounds of formula (X) in which 
D.noteq.D.sup.1 and/or A.noteq.A.sup.1 and/or p.noteq.p.sup.1 may be 
prepared by the reaction of compounds of the general formula (IX) with 
aryl halides of the general formula (V) in the presence of a palladium 
catalyst and/or a compound which is basic in reaction, optionally in the 
presence of a cocatalyst, a phosphane, a solvent and/or diluent and a 
phase transfer catalyst at temperatures from 40.degree. to 170.degree. C., 
preferably at 60.degree. to 130.degree. C. 
Preferred compounds of the formula (IX) are those in which R.sup.4 is 
C(CH.sub.3).sub.2 --OH or Si(CH.sub.3)CH.sub.3. 
Preferred compounds of formula (V) are those already mentioned in 
connection with formula (II). 
As regards the palladium catalyst, the cocatalyst, the base, the diluent 
and/or solvent and the addition of phosphane and phase transfer catalyst, 
the same applies as has already been described for the above mentioned 
variation. 
The quantity of aryl halide corresponding to formula (V) used is generally 
from 0.8 to 1.2 mol, preferably from 0.9 to 1.1 mol, per mol of the 
acetylene corresponding to formula (IX). The reaction of the compounds of 
formula (IX) with those of formula (V) may take place in the same manner 
as in the variation previously described. 
This variation is therefore illustrated below by way of example for the 
synthesis of Z,E-1,4-bis-(4-carboxystyryl)-benzene: 
##STR23## 
The reactions m) 2. and 3. serve to purify the reaction product. 
This invention further relates to new Z-stilbene compounds corresponding to 
the following formulae: 
##STR24## 
These new Z-stilbene compounds may be prepared by the process according to 
the invention described above or by its variations. 
The bifunctional Z-stilbene compounds prepared by the process according to 
the invention are eminently suitable for the preparation of polymers such 
as polyesters, polyester carbonates, polyamides, polycarbonates, 
polyurethanes, polyethers and polyphenylene sulphides. Their special 
properties distinguish them advantageously from known isomeric stilbene 
derivatives which have hitherto been used for the synthesis of polymers 
containing stilbene fragments (see e.g. U.S. Pat. No. 4,654,412). Thus the 
solubility differences between bifunctional Z- and E-stilbene monomers in 
solvents used for the preparation of polymers by phase interface 
condensation is considerable. 
It is possible, for example, to prepare an 11% solution of 
Z-stilbene-4,4'-dicarboxylic acid dichloride in dichloromethane whereas 
the chloride of the known E-stilbene-4,4'-dicarboxylic acid has a 
solubility of less than 1% and therefore cannot be used economically for a 
phase interface condensation, in contrast to the readily soluble 
Z-stilbene compound. It is obviously for this reason that processes for 
the preparation of polystilbene dicarboxylic acids by the phase interface 
condensation process have not hitherto become known. The bifunctional 
Z-stilbene compounds prepared according to the invention, which are in 
part new, have therefore made an important contribution to the 
manufacturing technique of both known and new materials containing 
polystilbene fragments, which materials are distinguished, for example, by 
their high temperature resistance.

EXAMPLES 
Example 1 
4-(Trimethylsilylethinyl)-benzoic acid tert.-butyl ester 
51.4 g of Bromobenzoic acid tert.-butyl ester, 21.6 g of 
trimethylsilylacetylene, 1.4 g of (Ph.sub.3 P).sub.2 PdCl.sub.2 in 400 ml 
of absolute acetonitrile and 100 ml of triethylamine are stirred under 
reflux for 8 hours in an atmosphere of nitrogen. After the reaction 
product has been worked up with CH.sub.2 Cl.sub.2 /H.sub.2 O and 
distilled, 40.6 g of 4-(trimethylsilylethinyl)-benzoic acid tert.-butyl 
ester are obtained. 
Bp..sub.0.04 mm : 120.degree.-130.degree. C. 
Mp.: 60.degree.-62.degree. C. 
NMR (CDCl.sub.3): .delta.=0.28 (s, 9H), 1.63 (s, 9H), 7.53 (m, 2H), 7.95 
(m, 2H). 
Example 2 
4-Ethinyl-benzoic acid tert.-butyl ester 
274.4 g of 4-(trimethylsilylethinyl)-benzoic acid tert.-butyl ester and 
12.5 g of anhydrous potassium carbonate in 1.5 l of absolute methanol are 
stirred together for 3 hours under nitrogen. The reaction mixture is then 
concentrated by evaporation and worked up with CH.sub.2 Cl.sub.2 /H.sub.2 
O to yield 194 g of 4-ethinyl-benzoic acid tert.-butyl ester. 
Mp.: 70.degree.-71.degree. C. 
NMR (CDCl.sub.3): .delta.=1.58 (s, 9H), 3.22 (s, 1H), 7.52 (m, 2H), 7.94 
(m, 2H). 
Example 3 
4,4'-Tolan-dicarboxylic acid-di-tert.-butyl ester 
4-Bromo-benzoic acid tert.-butyl ester, 5.1 g of triphenylphosphine and 375 
ml of NEt.sub.3 are introduced into 1 l of absolute acetonitrile under 
nitrogen and N.sub.2 is passed through the solution for 20 minutes. 10.5 g 
of (P.phi..sub.3).sub.2 PdCl.sub.2 and 1.5 g of copper(I)iodide are then 
added and 166.5 g of 4-ethinyl-benzoic acid tert.-butyl ester dissolved in 
1 l of absolute acetonitrile are slowly added dropwise under reflux and 
the reaction mixture is stirred overnight. The resulting reaction mixture 
is then suction filtered after cooling, stirred up in water, again suction 
filtered, dissolved in CH.sub.2 Cl.sub.2 and filtered after the addition 
of a small quantity of Tonsil, and the solvent is then evaporated off 
under vacuum. 225 g of 4,4'-Tolan-dicarboxylic acid-di-tert.-butyl ester 
are obtained. 
Mp.: 163.degree. C. 
NMR (CDCl.sub.3): .delta.=1.60 (s, 18H), 7.58 (m, 4H), 7.98 (m, 4H) 
Example 4 
4,4'-Tolan-dicarboxylic acid di-tert.-butyl ester 
A mixture of 514 g of 4-bromobenzoic acid tert.-butyl ester, 88.25 g of 
2-methyl-3-butyn-2-ol and 74.5 g of triphenylphosphine in 1250 ml of 
toluene is added to 7.1 g of benzyl triethylammonium chloride, 9.55 g of 
copper(I)iodide and 14 g of (P.phi..sub.3).sub.2 PdCl.sub.2 and the 
reaction mixture is stirred at reflux for 48 hours after the addition of 
750 ml of 5.5 N NaOH. The organic phase is separated off, dried and 
concentrated by evaporation. 430 g of moist crude product are stirred up 
in 550 ml of methanol and suction filtered. 248 g of 
4,4'-tolan-dicarboxylic acid di-tert.-butyl ester are obtained and may be 
further purified by recrystallisation from acetonitrile. 
M.p. and NMR data correspond to those of the product obtained according to 
Example 3. 
Example 5 
Z-4,4'-Stilbene dicarboxylic acid di-tert.-butyl ester 
52.6 g of Zn and 70 ml of ethanol are heated together with 13 g of 
1,2-dibromoethane until evolution of gas ceases. A solution of 13 g of 
CuBr and 15.8 g of anhydrous LiBr in 70 ml of THF is added at 40.degree. 
to 50.degree. C. and the reaction mixture is stirred for 10 minutes. A hot 
solution of 50 g of 4,4'-tolan-dicarboxylic acid di-tert.-butyl ester in 
70 ml of ethanol and 130 ml of THF is added and the mixture is heated 
under reflux for 72 hours. After filtration, the filtrate is concentrated 
by evaporation, taken up with CH.sub.2 Cl.sub.2, washed twice with dilute 
HCl and H.sub.2 O, dried and concentrated by evaporation. 46.3 g of 
Z-4,4'-stilbene dicarboxylic acid di-tert.-butyl ester are obtained. 
M.p.: 126.degree.-127.degree. C. 
NMR (CDCl.sub.3): .delta.=1.58 (s, 18H), 6.69 (s, 2H), 7.24 (m, 4H), 7.84 
(m, 4H). 
Example 6 
Z-(4,4'-Stilbene dicarboxylic acid 
331 g of Z-4,4'-Stilbene-dicarboxylic acid di-tert.-butyl ester in 1700 ml 
of absolute toluene are boiled under reflux for 3 hours together with 10.3 
g of p-toluene sulphonic acid. The reaction mixture is then concentrated 
by evaporation and boiled under reflux for 4 hours with 104.2 g of NaOH, 
1300 ml of H.sub.2 O and 1300 ml of ethanol. The reaction mixture is 
filtered hot after the addition of active charcoal, diluted with about 3 l 
of H.sub.2 O and extracted twice, in each case with 1 l of CH.sub.2 
Cl.sub.2. Concentrated HCl is then added to the aqueous phase. 230 g of 
Z-4,4'-stilbene dicarboxylic acid are obtained after suction filtration 
and drying. 
M.p.: &gt;280.degree. C. 
NMR (DMSO-d.sub.6): .delta.=6.83 (s, 2H), 7.35 (m, 4H), 7.86 (m, 4H). 
Example 7 
Z-4,4'-Stilbene dicarboxylic acid dichloride 
100 g of Z-Stilbene-4,4'-dicarboxylic acid, 400 ml of thionyl chloride and 
3 drops of DMF are stirred at 40.degree. C. until evolution of gas ceases. 
The product is then filtered under nitrogen and evaporated to dryness. 95 
g of Z-4,4'-stilbene dicarboxylic acid dichloride are obtained. 
M.p.: 102.degree. C. 
NMR (CDCl.sub.3): .delta.=6.81 (s, 2H), 7.34 (m, 4H), 8.00 (m, 4H). 
An even purer product is obtained by subsequently recrystallising the 
reaction product from an inert solvent such as cyclohexane, benzene or 
toluene and then optionally treating the resulting crystallised product 
again with thionyl chloride, optionally in a suitable solvent such as 
CH.sub.2 Cl.sub.2. 
Example 8 
4-(4-Carbo-tert.-butoxyphenyl)-2-methyl-3-butyn-2-ol 
257.1 g of 4-Bromobenzoic acid tert.-butyl ester, 168 g of 
2-methyl-3-butyn-2-ol and 15.6 g of (Ph.sub.3 P).sub.2 PdCl.sub.2 in 1.5 l 
of absolute acetonitrile and 480 ml of triethylamine are stirred together 
at reflux for 6 hours under nitrogen. The product is then concentrated by 
evaporation and worked up with toluene/H.sub.2 O to yield 185 g of an oil 
which slowly crystallises. 
NMR (CDCl.sub.3): .delta.=1.60 (s, 9H), 1.65 (s, 6H), 7.43 (m,2H), 7.92 (m, 
2H). 
Example 9 
E-4-(Carbo-tert.-butoxy)-4'-(4-carbo-tert.-butoxystyryl)tolan 
A mixture of 13.02 g of 
4-(4-carbo-tert.-butoxyphenyl)-2-methyl-3-butyn-2-ol, 17.97 g of 
4-bromo-4'-carbo-tert.-butoxystilbene, 0.93 g of triphenylphosphine. 0.34 
g of benzyltriethylammonium chloride, 175 mg of 
bis(triphenylphosphine)palladium(II) chloride and 175 mg of copper(I) 
iodide in 70 ml of toluene and 36 ml of 5,5N NaOH is vigorously stirred 
under reflux for 48 hours. After the addition of 250 ml of saturated 
ammonium chloride solution, the reaction product is extracted with 
methylene chloride, dried and concentrated by evaporation. 
Yield: 22.1 g 
For characterisation see Example 10. 
Example 10 
E-4-(Carbo-tert.-butoxy)-4'-(4-carbo-tert.-butoxystyryl)tolan 
300 ml of NEt.sub.3 and 20.46 g of P.phi..sub.3 are added under nitrogen to 
234 g of 4-bromo-4'-carbo-tert.-butoxystilbene in 1 l of absolute 
acetonitrile. Nitrogen is passed through the stirred suspension for 20 
minutes and 9.12 g of (P.phi..sub.3).sub.2 PdCl.sub.2 and 2.5 g of 
copper(I)iodide are then added. 144 g of 4-Ethinyl benzoic acid 
tert.-butyl ester dissolved in 1 l of absolute acetonitrile are then added 
dropwise under reflux over a period of 6 hours and the reaction mixture is 
boiled under reflux overnight. The hot product obtained after suction 
filtration is dissolved in CH.sub.2 Cl.sub.2, washed several times with 
H.sub.2 O and dried and the solvent is removed. 
Yield: 275 g 
Mp.: 218.degree. C. (decomposition) 
NMR (CDCl.sub.3): .delta.=1.61 (s, 18H), 7.18 (s, 2H), 7.56 (m, 8H), 7.98 
(m, 4H). 
Example 11 
Z,E-1,4-Bis-(4-carbo-tert.-butoxystyryl)-benzene 
272 g of zinc dust in 270 ml of tert.-butanol are boiled with 24.9 ml of 
1,2-dibromoethane until evolution of gas ceases. 55.5 g of CuBr and 66.9 g 
of LiBr in 200 ml of THF are then carefully added at 50.degree. C. When 
the exothermic reaction has died down, 272 g of 
E-4-(carbo-tert.-butoxy)-4'-(4-carbo-tert.-butoxy-styryl)-tolan in 1.7 l 
of THF and 560 ml of tert.-butanol are added and the reaction mixture is 
heated under reflux for 4 days. The resulting reaction mixture is then 
evaporated to dryness, taken up in CH.sub.2 Cl.sub.2 and filtered and the 
filtrate is washed with dilute HCl, dried and concentrated by evaporation. 
Yield: 247 g 
Mp: 125.degree. C. 
NMR (CDCl.sub.3): .delta.=1.59 (s, 9H), 1.61 (s, 9H), 6.65 (m, 2H), 7.13 
(m, 2H), 7.23 (m, 2H), 7.31 (m, 2H), 7.40 (m, 2H), 7.51 (m, 2H), 7.86 (m, 
2H), 7.96 (m, 2H). 
Example 12 
Z,E-1,4-Bis-(4-carboxy-styryl)-benzene 
131 g of Z,E-1,4-Bis-(4-carbo-tert.-butoxy-styryl)benzene are boiled under 
reflux with 6.5 g of p-toluenesulphonic acid in 1 l of toluene for 3 
hours. The reaction product is evaporated to dryness and heated for a 
further 4 hours with 30 g of NaOH in 300 ml of water and 600 ml of 
ethanol. The ethanol is distilled off and the residue is acidified (conc. 
HCl) after dilution with water. The product is suction filtered and dried. 
Yield: 96 g 
NMR (DMSO-d.sub.6): .delta.=6.74 (m, 2H), 7.25 (m, 2H), 7.30-7.45 (m, 4H), 
7.54 (m, 2H), 7.70 (m, 2H), 7.86 (m, 2H), 7.96 (m, 2H), 12.9 (broad, OH). 
Example 13 
1-(4-Carbo-tert.-butoxyphenyl)-2-(4'-carbethoxy-biphenyl-4-yl)-ethyne 
100 ml of triethylamine, 6.3 g of triphenylphosphine, 2.81 g of 
(P.phi..sub.3).sub.2 PdCl.sub.2 and 0.77 g of copper(I)iodide are added 
under nitrogen to 61 g of 4-bromo-4'-carbethoxybiphenyl in 300 ml of 
absolute acetonitrile. 44.3 g of 4-ethinyl-benzoic acid tert.-butyl ester 
dissolved in 300 ml of absolute acetonitrile are slowly added dropwise at 
the reflux temperature and the reaction mixture is boiled overnight. It is 
then suction filtered while hot and stirred up in water and again suction 
filtered and the residue is dissolved in CH.sub.2 Cl.sub.2 and filtered 
after the addition of Tonsil. 
Yield: 73.2 g 
Mp.: 169.degree.-170.degree. C. 
NMR (CDCl.sub.3): .delta.=1.41 (t, 3H), 1.60 (s, 9H), 4.41 (q, 2H), 7.58 
(m, 2H), 7.63 (s, 4H), 7.68 (m, 2H), 7.98 (m, 2H), 8.13 (m, 2H). 
Example 14 
Z-1-(4-Carbo-tert.-butoxyphenyl)-2-(4'-carbethoxybiphenyl-4-yl)ethene 
50.6 g of zinc, 54 ml of absolute ethanol and 10.7 ml of 1,2-dibromoethane 
are boiled until evolution of gas ceases. A solution of 10.7 g of CuBr and 
12.7 g of LiBr in 54 ml of absolute THF is then added at 50.degree. C. 
After 5 minutes, 47.8 g of 
1-(4-carbo-tert.-butoxyphenyl)-2-4'-carbethoxybiphenyl-4-yl)-ethyne in 100 
ml of absolute THF and 30 ml of absolute ethanol are added and the 
reaction mixture is boiled under reflux for 5 days. The product is then 
suction filtered, concentrated by evaporation and worked up with CH.sub.2 
Cl.sub.2 /1 N HCl. 
Yield: 31.2 g 
NMR (CDCl.sub.3): .delta.=1.40 (t, 3H), 4.40 (q, 2H), 6.72 (m, 2H), 7.31 
(m, 2H), 7.38 (m, 2H), 7.53 (m, 2H), 7.65 (m, 2H), 8.00 (m, 2H) 8.10 (m, 
2H). 
The signals partly overlap. 
Example 15 
Z-1-(4-Carboxyphenyl)-2-(4'-carboxybiphenyl-4-yl)-ethene 
31.2 g of 
1-(4-Carbo-tert.-butoxyphenyl)-2-(4'-carbethoxybiphenyl-4-yl)-ethene in 
150 ml of absolute toluene are boiled under reflux for 3 hours with 1 g of 
p-toluene sulphonic acid. The reaction mixture is then evaporated to 
dryness, 8.68 g of NaOH in 100 ml of H.sub.2 O and 100 ml of ethanol are 
added, and the mixture is boiled for 4 hours. It is then filtered hot 
after the addition of active charcoal, diluted with 200 ml of H.sub.2 O 
and extracted twice with CH.sub.2 Cl.sub.2, and the product is 
precipitated from the aqueous phase with conc. HCl. 
Yield: 17.75 g 
NMR (DMSO-d.sub.6): .delta.=6.78 (m, 2H), 7.34 (m, 2H), 7.40 (m, 2H) 7.67 
(m, 2H), 7.80 (m, 2H), 7.88 (m, 2H) 8.04 (m, 2H), 12.91 (broad) OH). 
Example 16 
4-Bromotolan-4'-carboxylic acid-tert.-butyl ester 
2.8 g (Ph.sub.3 P).sub.2 PdCl.sub.2 and 400 mg of CuI are added to a 
solution of 40.4 g of 4-ethinyl-benzoic acid tert.-butyl ester, 56.6 g of 
bromoiodobenzene and 1.34 g of Ph.sub.3 P in 50 ml of diethylamine and 300 
ml of absolute acetonitrile and the reaction mixture is stirred for 72 
hours at 40.degree. C., suction filtered and dried. 
Yield: 50.5 g 
Mp.: 115.degree.-116.degree. C. 
NMR (CDCl.sub.3): .delta.=1.59 (s, 9H, 7.3-7.6 (m, 6H), 7.96 (m, 2H). 
Example 17 
Z-4-Bromo-4'-carbo-tert.-butoxystilbene 
56 g of Zn and 14 g of 1,2-dibromoethane are boiled in 70 ml of ethanol 
until evolution of gas ceases. 14 g of copper bromide and 16.8 g of 
lithium bromide in 70 ml of THF are then added, followed by 50 g of 
4-bromotolan-4'-carboxylic acid tert.-butyl ester in 250 ml of THF and 50 
ml of ethanol and the reaction mixture is boiled under reflux for 44 
hours. The resulting reacting mixture is filtered, concentrated by 
evaporation, taken up with CH.sub.2 Cl.sub.2, washed with dilute 
hydrochloric acid, dried and concentrated by evaporation. 
Yield: 40 g somewhat contaminated with Z-4-stilbenecarboxylic acid 
tert.-butyl ester. 
Example 18 
Z,E,Z-1,2-Bis-(4-carbo-tert.-butoxystilbenyl-4')-ethene 
Ethylene is passed through a solution of 17.9 g of 
Z-4-bromo-4'-carbo-tert.-butoxystilbene, 9.82 g of potassium acetate, 0.91 
g of triphenylphosphine and 0.11 g of (P.phi..sub.3).sub.2 PdCl.sub.2 in 
150 ml of absolute DMF at 100.degree. C. The reaction mixture is diluted 
with water, extracted with ether, thoroughly washed several times with 
water, dried and concentrated by evaporation and the residue is stirred up 
with petroleum ether. 
Yield: 3.2 g 
NMR (CDCl.sub.3): .delta.=1.55 (s, 18H), 7.62 (m, 4H), 7.02 (s, 2H), 
7.15-7.45 (m, 12H), 7.86 (m, 4H).