Process for the preparation of geminal diarylalkanes, new geminal diarylalkanes and alk(en)ylated aromatic compounds

The invention relates to a new process for the preparation of geminal diarylalkanes of the formula ##STR1## by Friedel-Crafts alkylation of aromatic compounds with specific aliphatic halogen compounds (addition compounds of CCl.sub.4 , to .alpha.-olefins), to new geminal diarylalkanes and the aralkyl compounds resulting as intermediates.

The invention relates to a new process for the preparation of geminal 
diarylalkanes, to new geminal diarylalkanes and to new alk(en)ylated 
aromatic compounds. 
1,1-Diarylalkanes are easily obtainable by acid-catalyzed alkylation of 
aromatic compounds with aldehydes or styrenes (see, for example, J. Org. 
Chem. 26 (1961) p. 1398). The preparation of geminal diarylalkanes with 
non-terminal geminal aryl groups, which could be carried out, in 
principle, by condensation of aliphatic ketones or .alpha.-methylstyrenes 
with aromatic compounds, is limited, however, to the use of activated 
aromatic compounds such as phenols and anilines. Toluene, for example, 
cannot be condensed with acetone or methylstyrenes to give the 
corresponding 2,2-diarylpropanes (see J. Org. Chem. loc. cit.). 
The preparation of geminal diarylalkanes with non-terminal aryl groups, for 
example 2,2-ditolylpropane, causes considerable difficulties and requires 
special alkylating agents and Friedel-Crafts catalysts in each case for 
each aromatic compound (see J. Org. Chem. loc. cit. and J. Org. Chem. 41 
(1976) p. 1698 ff., in particular p. 1701). 
As geminal diarylalkanes, especially also those with non-terminal aryl 
groups, have a considerable industrial interest as starting compounds, 
inter alia for the preparation of plastics (for example polyimides), the 
object was therefore to find an economical process by which geminal 
diarylalkanes could be prepared from all sorts of aromatic compounds. 
Surprisingly, it has been found that certain 1,1,1,3-tetrachloropropanes or 
the isomeric 1,1,1-trichloro-2- or 1,1,3-trichloro-1-propenes obtainable 
from these by HCl elimination represent ideal aliphatic condensation 
components for aromatic compounds, as, per mole, they react with 2 moles 
of all sorts of aromatic compounds, activated or non-activated, in the 
presence of customary Friedel-Crafts catalysts with elimination of 
vinylidene chloride to give geminal diarylalkanes. Surprisingly, the 
Friedel-Crafts reaction of tetrachloropropanes (trichloropropenes) does 
not stop at the stage of the aralkyl compounds, but these aralkyl 
compounds react with further aromatic compound with the elimination of 
vinylidene chloride to give the desired geminal diarylalkanes. 
This reaction of the tetrachloropropanes or trichloropropenes to be used 
according to the invention with aromatic compounds to give diarylalkanes 
has the advantage compared to the known processes that it is widely 
applicable, i.e. to all sorts of aromatic compounds, and the preparation 
of geminal diarylalkanes, which were hitherto not accessible at all or 
only in laboratory amounts, is made possible in industrial amounts, that 
it only requires customary Friedel-Crafts catalysts and that the 
halogenoalkanes or halogenoalkenes to be used as alkylating agents are 
obtainable by addition of CCl.sub.4 to basic petrochemicals, namely 
.alpha.-olefins such as propene, i-butene, 2-methyl-1-butene, 2-methyl- 
1-pentene, 4-methyl-1-pentene, n-octene, n-dodecene, n-heptadecene and 
n-octadecene and are therefore easily accessible. CCl.sub.4 is produced in 
a substantial amount as a chlorolysis product since organic 
chlorine-containing residues are customarily worked up by chlorolysis and 
new areas of use for CCl.sub.4 are therefore sought. 
The process according to the invention indicates an efficient route to 
convert this CCl.sub.4, which can be prepared from waste products in a 
large amount, on the one hand into the desired geminal diarylalkanes but 
also on the other hand into the vinylidene chloride obtained as the 
coupling product; vinylidene chloride is a monomer which is in demand for 
the preparation of useful copolymers (for example modacrylic fibres, saran 
polymers). 
That is to say, in the course of the newly found reaction, a conversion of 
the CCl.sub.4 obtained during the residual chlorolysis (i.e., a C.sub.1 
-compound with limited utility) takes place to give a C.sub.2 -compound 
having substantially wider utility (vinylidene chloride) as a result of 
the use of the halogenoalkanes or halogenoalkenes prepared from CCl.sub.4 
and olefins and their reaction with aromatic compounds to give 
diarylalkanes and vinylidene chloride. 
The invention therefore relates to a process for the preparation of 
monomeric or oligomeric geminal diarylalkanes of the formula 
##STR2## 
in which 
n is an integer from 1 to 5 or, preferably, zero, 
##STR3## 
independently of one another represent an optionally substituted aryl 
radical and 
##STR4## 
either denotes a 
##STR5## 
radical, 
R.sub.1 represents hydrogen or a C.sub.1 -C.sub.18 -alkyl radical and 
R.sub.2 represents hydrogen or an optionally substituted C.sub.1 -C.sub.18 
-alkyl radical, 
which is characterized in that aromatic compounds of the formulae 
##STR6## 
in which 
##STR7## 
have the meaning indicated under formula (I), are reacted with an 
aliphatic halogen compound of the formulae 
##STR8## 
in which 
R.sub.1 and R.sub.2 have the meaning indicated under formula (I), in the 
presence of Friedel-Crafts catalysts. 
The molar ratios in which the aromatic compounds II and the aliphatic 
halogen compounds III are employed depends on the desired final products, 
and whether monomeric or oligomeric diarylalkanes are desired. For the 
preparation of monomeric geminal diarylalkanes (compounds of the formula 
(I) in which n is zero), the aromatic compounds II are employed in excess, 
preferably in an amount of 10 to 30 moles per mole of aliphatic halogen 
compound. For the preparation of the oligomeric geminal diarylalkanes 
(compounds of the formula (I) in which n is an integer from 1 to 5), the 
aromatic compounds and aliphatic halogenoalkanes are used, depending on 
the degree of oligomerization desired, in a molar ratio of 1:1 to 5:1. 
The process according to the invention can be carried out both in the 
liquid phase and in the gas phase. When carrying out the process in the 
liquid phase, it is preferably carried out at temperatures of -50.degree. 
to +200.degree. C., preferably -20.degree. to +150.degree. C. 
Friedel-Crafts catalysts employed are the Friedel-Crafts catalysts 
customarily used for the alkylation of aromatic compounds, for example 
AlCl.sub.3, BF.sub.3, FeCl.sub.3, ZnCl.sub.2, TiCl.sub.4, ZrCl.sub.4, 
SnCl.sub.4, H.sub.3 PO.sub.4, HF, HBF.sub.4, acidic alkaline earth 
phosphates, aluminas, zeolites or acidic ion exchange resins. If 
appropriate, the additional use of co-catalysts, as are frequently used in 
the Friedel-Crafts alkylation, may be advantageous for the acceleration of 
the reaction; a co-catalyst of this type is, for example, HCl. 
The liquid phase alkylation according to the invention can be carried out, 
for example, as follows: one of the halogenoalkanes of the formula 
(IIIa-c), a mixture of these compounds or a solution of the compounds in 
an organic solvent is added with stirring at temperatures of -10.degree. 
to +50.degree. C. to the solution of the Friedel-Crafts catalyst in excess 
aromatic compound or in the aromatic compound diluted with an inert 
organic solvent, such as methylene chloride. The reaction mixture is 
stirred further at temperatures of 0.degree. to +50.degree. C. for some 
time, 10 min. to 20 hours depending on the batch size, in order to 
complete the reaction. The catalyst is then deactivated by adding water. 
The organic phase of the reaction mixture is separated off and, after 
drying, worked up by distillation. 
When carrying out the process according to the invention in the gas phase, 
the reaction is carried out at temperatures of about 200.degree. to 
450.degree. C. Catalysts used are the Friedel-Crafts catalysts such as 
Al.sub.2 O.sub.3 .multidot.SiO.sub.2, H.sub.3 PO.sub.4 
.multidot.SiO.sub.2, BF.sub.3 /.sub..gamma. Al.sub.2 O.sub.3 and acidic 
zeolites customarily used for gas phase alkylations of aromatic compounds. 
The gas phase alkylation according to the invention is carried out as 
follows: the aromatic compounds (II) and aliphatic halogen compounds 
IIIa-c are brought into the gaseous state by heating in a suitable 
apparatus, for example a coil or falling film evaporator, and transferred 
to a suitable reactor for continuous gas phase processes, for example a 
tube bundle reactor, which contains the alkylation catalyst in solid form. 
The reaction mixture leaving the reactor is separated into liquid and 
gaseous products by condensation. 
The pure substances are obtained by fractional distillation, it optionally 
being possible beforehand to remove hydrogen chloride by washing 
processes, for example with water. 
The condensation reaction on which the process according to the invention 
is based proceeds in two stages: 
##STR9## 
The process according to the invention can be carried out as one step or 
two steps, depending on whether it is wished to stop the alkylation 
reaction at the stage of the aralkyl compounds IVa or b or whether it is 
wished immediately to obtain the geminal diarylalkanes of the formula (I). 
The two stage procedure is preferably used for the preparation of geminal 
diarylalkanes of the formula (I) in which 
##STR10## 
represent different aryl radicals. 
In the two stage procedure, the condensation of the aromatic compounds in 
the first reaction stage with the aliphatic halogen compounds IIIa-c is 
carried out using weakly active Friedel-Crafts catalysts such as 
ZnCl.sub.2, ZnI.sub.2 or SnCl.sub.4 and/or at low temperatures such as 
-70.degree. to +10.degree. C. and in short reaction times. 
For the second stage, the condensation of the aralkyl compounds IVa or b 
with further aromatic compound II, stronger Friedel-Crafts catalysts such 
as AlCl.sub.3 and higher temperatures such as +25.degree. C. to 
+150.degree. C. are used, as for the one stage procedure. 
As already emphasized, the process according to the invention is suitable 
for the preparation of geminal diarylalkanes from all sorts of aromatic 
compounds. Suitable aromatic compounds are, for example, benzene, toluene, 
o-, m- and p-xylene, diphenylmethane, 2,2-diphenylpropane, diphenyl, 
4-methyl-diphenyl, naphthalene, 1- and 2-methylnaphthalene, 
2,3-dimethyl-naphthalene, acenaphthene, chlorobenzene, bromobenzene, 
fluorobenzene, phenol, o-, m- and p-cresol, anisole, phenetole, diphenyl 
ether, thiophenol and diphenyl thioether. 
Correspondingly, examples of optionally substituted aryl radicals 
##STR11## 
which may be mentioned are: phenyl, biphenyl, diphenylmethane, 
2,2-diphenylpropane and naphthyl radicals optionally substituted by 
C.sub.1 -C.sub.4 -alkyl such as methyl, ethyl, isopropyl; hydroxyl; 
C.sub.1 -C.sub.4 -alkoxy such as methoxy and ethoxy; phenoxy; mercapto; 
C.sub.1 -C.sub.4 -alkylmercapto such as methylmercapto; phenylmercapto; 
and by halogen such as fluorine, chlorine or bromine, and in addition the 
acenaphthyl radical. 
C.sub.1 -C.sub.18 -Alkyl radicals which may be mentioned for R.sub.1 and 
R.sub.2 are: 
the methyl, ethyl, propyl, butyl, octyl, dodecyl, heptadecyl and octadecyl 
radical; suitable substituents for R.sub.2 are, above all, halogen atoms 
such as chlorine atoms. 
The geminal diarylalkanes of the formula (I) obtainable by the process 
according to the invention are mostly new. The new monomeric compounds are 
useful intermediates for the preparation of plastics, for example 
polyimides. The new geminal diarylalkanes, in particular the 
2,2-diarylpropanes whose aryl groups are substituted by two vicinal methyl 
groups, open up the possibility of preparing new polyimides, which could 
not be prepared hitherto, with new interesting properties. The vicinal 
methyl groups of the aryl radicals are converted into carboxyl groups by 
oxidation, and the tetracarboxylic acids thus obtained are reacted with 
diamines to give polyimides. 
The new oligomeric diarylalkanes are suitable as electrical insulating 
fluids and heat transfer fluids. 
The invention therefore also relates to new geminal diarylalkanes; these 
correspond to the formula 
##STR12## 
in which, for the case in which 
n' is an integer from 1 to 5, 
##STR13## 
independently of one another, represent an optionally substituted aryl 
radical and 
##STR14## 
either denotes 
##STR15## 
radical, with the proviso that when 
##STR16## 
is phenyl or hydroxyphenyl, 
##STR17## 
R.sub.1 ' represents hydrogen or a C.sub.1 -C.sub.18 -alkyl radical and 
R.sub.2 ' denotes hydrogen or an optionally substituted C.sub.1 -C.sub.18 
-alkyl radical, 
and in which, for the case in which 
n' is zero, 
##STR18## 
represents 
##STR19## 
represents 
##STR20## 
R.sub.1 ' represents methyl and 
R.sub.2 ' represents hydrogen or methyl. 
Examples of representatives of the new diarylalkanes of the formula (VI), 
when n'=0 in this, which may be mentioned are: 
1-phenyl-1-xylyl-ethane, 2-phenyl-2-xylyl-propane, 
2,2-bis-(4-chlorophenyl)-propane, 2,2-bis-(biphenyl)-propane, 
2-biphenyl-2-xylyl-propane, 
1-biphenyl-1-tolyl-ethane,2-biphenyl-2-tolyl-propane,2-biphenyl-2-phenyl-p 
ropane,2-phenyl-2-tolyl-propane, 2,2-bis-(p-phenoxy-phenyl)-propane, 
2-phenyl-2-(p-phenoxy-phenyl)-propane and 
2-(p-phenoxy-phenyl)-2-xylyl-propane. 
The aralkyl compounds of the formulae (IVa and b) obtainable in the two 
stage implementation of the process according to the invention are also 
new; it has been found that these are not only intermediates for the 
preparation, in particular, of asymmetrical geminal diarylalkanes of the 
formula (I) but that they are also interesting intermediates for the 
preparation of plant protection agents and, for example, open up a new 
more favourable route for the preparation of known active compounds. 
The invention therefore also relates to the aralkyl compounds of the 
formulae (IVa and b) in which 
##STR21## 
R.sub.1 and R.sub.2 have the meaning indicated under formula (I). 
Examples of representatives of these new aralkyl compounds which may be 
mentioned are: 
1,1,1-trichloro-3-methyl-3-phenyl-butane 
1,1,1-trichloro-3-methyl-3-tolyl-butane 
1,1,1-trichloro-3-methyl-3-xylyl-butane 
1,1,1-trichloro-3-methyl-3-chlorophenyl-butane 
1,1,1-trichloro-3-methyl-3-bromophenyl-butane 
1,1,1-trichloro-3-methyl-3-fluorophenyl-butane 
1,1,1-trichloro-3-methyl-3-ethoxyphenyl-butane 
1,1,1-trichloro-3-methyl-3-hydroxyphenyl-butane 
1,1,1-trichloro-3-methyl-3-mercaptophenyl-butane 
1,1,1-trichloro-3-methyl-3-methylmercapto-phenyl-butane 
1,1,1-trichloro-3-methyl-3-tolyl-butane 
1,1,1-trichloro-3-methyl-3-xylyl-pentane 
1,1,1-trichloro-3-methyl-3-chlorophenyl-pentane 
1,1,1-trichloro-3-methyl-3-fluorophenyl-pentane 
1,1,1-trichloro-3-methyl-3-ethoxyphenyl-pentane 
1,1,1-trichloro-3,4-dimethyl-3-tolyl-pentane 
1,1,1-trichloro-3,4-dimethyl-3-xylyl-pentane 
1,1,1-trichloro-3,4-dimethyl-3-fluorophenyl-pentane 
1,1,1-trichloro-3,4-dimethyl-3-ethoxyphenyl-pentane 
1,1,1-trichloro-3-methyl-3-biphenyl-butane 
1,1,1-trichloro-3-methyl-3-biphenyl-pentane 
1,1,1-trichloro-3-methyl-3-naphthyl-butane 
1,1,1-trichloro-3-methyl-3-dimethylnaphthyl-butane 
1,1,1-trichloro-3-methyl-3-acenaphthyl-butane 
1,1,1-trichloro-3-methyl-3-phenoxyphenyl-butane 
1,1-dichloro-3-phenyl-butene 
1,1-dichloro-3-tolyl-butene 
1,1-dichloro-3-hydroxyphenyl-butene 
1,1-dichloro-3-methoxyphenyl-butene 
1,1-dichloro-3-fluorophenyl-butene 
1,1-dichloro-3-cumyl-butene 
1,1-dichloro-3-biphenyl-butene 
1,1-dichloro-3-phenyl-pentene 
1,1-dichloro-3-tolyl-pentene 
1,1-dichloro-3-methoxyphenyl-pentene 
1,1-dichloro-3-ethoxyphenyl-pentene 
1,1-dichloro-3-hydroxyphenyl-pentene 
1,1-dichloro-3-phenyl-heptene 
1,1-dichloro-3-tolyl-undecene 
1,1-dichloro-3-phenyl-heptadecene 
1,1-dichloro-3-phenyl-nonadecene 
1,1-dichloro-3-methyl-3-phenyl-butene 
1,1-dichloro-3-methyl-3-tolyl-butene 
1,1-dichloro-3-methyl-3-chlorophenyl-butene 
1,1-dichloro-3-methyl-3-xylyl-butene 
1,1-dichloro-3-methyl-3-ethoxyphenyl-butene 
1,1-dichloro-3-methyl-3-hydroxyphenyl-butene 
1,1-dichloro-3-methyl-3-tolyl-pentene 
1,1-dichloro-3-methyl-3-ethoxyphenyl-pentene 
1,1-dichloro-3-methyl-3-xylyl-pentene 
1,1-dichloro-3,4-dimethyl-3-phenyl-pentene 
1,1-dichloro-3,4-dimethyl-3-tolyl-pentene 
1,1-dichloro-3,4-dimethyl-3-xylyl-pentene 
1,1-dichloro-3,4-dimethyl-3-fluorophenyl-pentene 
1,1-dichloro-3,4-dimethyl-3-ethoxyphenyl-pentene 
The significance of the compounds IVa and b as intermediates for the 
preparation of plant protection agents may be illustrated as exemplified 
by the preparation of insecticides of the type MTI 800 (see DE-OS (German 
Published Specification) 3,317,907). A multistage process is described for 
the preparation of these aromatic alkane derivatives which requires 
complicated reactions and the use of expensive reagents which can only be 
handled with difficulty on the industrial scale, such as Grignard 
compounds and LiAlH.sub.4 (see DE-OS (German Published Specification) 
3,317,908, and the reaction scheme on p. 62/63). With the aid of the 
aralkyl compounds of the formulae IVa and b according to the invention, 
not only the number of reaction steps can be substantially lowered, but 
the individual reactions can be carried out without difficulties on the 
industrial scale, as they only require simple reagents customarily used in 
chemical techniques. 
That is to say that, with the aid of the aralkyl compounds of the formula 
IVa and b according to the invention, the active compounds described in 
DE-OS (German Published Specification) 3,317,908 can be prepared in a 
simplified, essentially more economical way.

EXAMPLE 1 
25 g (0.12 mol) of 1,1,1,3-tetrachloro-3-methylbutane in 250 g (3.2 mol) of 
benzene are added in the course of 15 min with stirring and cooling at 
temperatures of 0.degree. to 5.degree. C. to a solution of 2.5 g (0.019 
mol) of AlCl.sub.3 in 10 ml of dichloromethane. The reaction mixture is 
stirred at 5.degree. C. for 100 min. After adding 50 ml of water, the 
organic phase is separated off, dried and fractionally distilled. 
268 g of crude product are obtained, which according to GC analysis 
contains 4.1% of vinylidene chloride.(=11 g=94.8% of theory). 20.4 g (=87% 
of theory) of 2,2-diphenyl-propane (b.p.: 89.degree. C./0.1 mbar) are 
obtained by fractional distillation of the crude product. 
EXAMPLE 2 
500 g (2.38 mol) of 1,1,1,3-tetrachloro-3-methylbutane are added in the 
course of 10 min. with stirring and cooling at 0.degree. C. to a solution 
of 20 g (0.15 mol) of AlCl.sub.3 in 2,500 g (27 mol) of dry toluene. The 
reaction mixture is stirred at 0.degree. C. for 60 min and, after adding 
200 ml of water, the organic phase is separated off, dried using sodium 
sulphate and worked up by fractional distillation. 
145 g (=72% of theory) of vinylidene chloride, 90 g of unreacted 
1,1,1,3-tetrachloro-3-methyl-butane and 410 g (=94% of theory) of 
2,2-di-tolyl-propane (isomer mixture; b.p.: 106.degree.-115.degree. C./0.1 
mbar) are obtained. Content of p,p'-isomer of the isomer mixture: 65%. 
EXAMPLE 3 
100 g (0.48 mol) of 1,1,1,3-tetrachloro-3-methyl-butane are added with 
stirring at room temperature to a solution of 2.5 g (0.015 mol) of 
anhydrous FeCl.sub.3 in 1,400 g (15.2 mol) of anhydrous toluene. The 
reaction mixture is stirred at 50.degree. to 60.degree. C. for 60 min and 
then at reflux temperature for 180 min. After adding water, the organic 
phase is separated off, dried and worked up by distillation. 
80.8 g (=73.5% of theory) of 1,1-dichloro-3-tolyl-3-methyl-but-1-ene are 
obtained (b.p.: 85.degree.-89.degree. C./0.2 mbar). 
EXAMPLE 4 
500 g (2.38 mol) of 1,1,1,3-tetrachloro-3-methylbutane are added with 
stirring and cooling at temperatures of 0.degree. to 10.degree. C. in the 
course of 30 min to a solution of 50 g (0.38 mol) of AlCl.sub.3 in 5,000 g 
(44.6 mol) of dry chlorobenzene. The reaction mixture is stirred at 
10.degree. C. for a further 90 min. After adding 500 ml of water, the 
organic phase is separated off, washed with soda solution until neutral 
and dried using sodium sulphate. 
The following are obtained in the fractional distillation: 4,750 g of 
precursor; it contains 4.5% (=213 g=92.6% of theory) of vinylidene 
chloride according to GC analysis; 532 g (=84.3% of theory) of 
2,2-bis-(chlorophenyl)-propane (predominantly the p,p'-isomer) (b.p.: 
160.degree.-165.degree. C./0.8 mbar) and 84 g ,(=14% of theory) of 
1,1-dichloro-3-chlorophenyl-3-methyl-butene (predominantly the 
p,p'-isomer) (b.p.: 115.degree.-118.degree. C./0.3 mbar). 
EXAMPLE 5 
30 g (0.14 mol) of 1,1,1,3-tetrachloro-3-methylbutane are added with 
stirring to a solution of 2 g (0.015 mol) of AlCl.sub.3, 462 g (3.0 mol) 
of diphenyl and 106 g (1.0 mol) of o-xylene in 450 ml of methylene 
chloride. The reaction mixture is stirred at 10.degree. C. for a total of 
20 hours, a further 2 g of AlCl.sub.3 being additionally added after 5 and 
7 hours in each case. After adding 50 ml of water, the organic phase is 
separated off and, after drying, worked up by distillation. 
Unreacted o-xylene and diphenyl ar recovered. 13.8 g (=32% of theory) of a 
fraction of boiling range 210.degree.-225.degree. C./0.2 mbar consisting 
predominantly of 2-biphenyl-2-xylyl-propane and 15 g (=30% of theory) of a 
fraction of boiling range 225.degree.-250.degree. C./0.2 mbar consisting 
essentially of 2,2-bis-(biphenyl)-propane are obtained. m.p. of the 
2,2-bis-(biphenyl)-propane purified by recrystallization from hexane: 
138.degree.-139.degree. C. 
EXAMPLE 6 
30 g (0.14 mol) of 1,1,3-trichloro-but-1-ene are added in the course of 30 
min at 0.degree. C. with stirring and cooling to a solution of 2.8 g of 
AlCl.sub.3 (0.02 mol) in 300 ml (3.0 mol) of dry benzene. The reaction 
mixture is stirred at 0.degree. to 5.degree. C. for a further 90 min. 
After adding 50 ml of water, the organic phase is separated off and worked 
up by fractional distillation. 
27 g (=71% of theory) of 1,1-dichloro-3-phenyl-but-1-ene (b.p.: 
73.degree.-74.degree. C./0.15 mbar) and 2.6 g (=7.6% of theory) of 
1,1-bisphenyl-ethane (b.p.: 87.degree.-89.degree. C./0.1 mbar) are 
obtained. 
EXAMPLE 7 
The reaction was carried out as described in Example 6 with the difference 
that the reaction temperature was 25.degree. C. and the reaction time 18 
hours. The precursor (210 g) removed by distillation under normal pressure 
contains 5.9% (=13.4 g=91% of theory) of vinylidene chloride according to 
GC analysis. 18.2 g (=53% of theory) of 1,1-bisphenylethane (b.p.: 
88.degree.-90.degree. C./0.1 mbar) are obtained in the subsequent vacuum 
distillation. 
EXAMPLE 8 
First 5 g of AlCl.sub.3 and then 30 g of 1,1,1,3 
-tetrachloro-3-methyl-butane are added with stirring and cooling to a 
solution of 500 g of diphenyl ether in 300 ml of dichloromethane. After 
stirring for 5 hours, 5 g of AlCl.sub.3 are again added and the reaction 
mixture is warmed to 22.degree. C. After a further reaction time of 10 
hours, 200 ml of water are added dropwise and the phases are separated. 
The organic phase which has been dried using sodium sulphate is distilled. 
33.3 g (=61% of theory) of 2,2-bis-(4-phenoxyphenyl)-propane (b.p.: 
225.degree.-230.degree. C./0.6 mbar) are obtained. 
EXAMPLE 9 
1 g of AlCl.sub.3 and 30 g of 1,1,1,3-tetrachloro-3-methyl-butane are added 
at 0.degree. C. to a solution of 154 g of biphenyl in 312 g of benzene. 
After stirring for 5 hours, a further 2 g of AlCl.sub.3 are added and the 
reaction mixture is stirred at 20.degree.-25.degree. C. for a further 10 
hours. After adding 50 ml of water, the phases are separated. The organic 
phase is worked up by distillation. 
13.5 g of 2-biphenyl-2-phenyl-propane (b.p.: 190.degree.-195.degree. 
C./0.05 mbar) are obtained in addition to 2,2-diphenylpropane and 
2,2-bis-(biphenyl)-propane. 
EXAMPLE 10 
300 g of 1,1,1,3-tetrachloro-3-methyl-butane are slowly added at 0.degree. 
C. with stirring and cooling to a mixture of 2,400 ml of benzene, 600 ml 
of o-xylene and 12 g of AlCl.sub.3. After stirring for 5 hours, the 
reaction is terminated by adding 250 ml of water. The organic phase is 
worked up by distillation. Vinylidene chloride, benzene and o-xylene are 
first removed by distillation under normal pressure; 290 g of unreacted 
1,1,1,3-tetrachloro- 3-methyl-butane, 33 g of 2-phenyl-2-o-xylylpropane 
(boiling range: 130.degree. C.-134.degree. C./0.4 mbar) and 61 g of 
2,2-bis-(o-xylyl)-propane (b.p.: 158.degree. C.-160.degree. C./0.2 mbar) 
are then obtained by vacuum distillation. 
EXAMPLE 11 
25 g of AlCl.sub.3 are dissolved in 2,700 ml of anhydrous o-xylene with 
stirring. 270 g of 1,1,1,3-tetrachloro-3-methyl-butane are then added 
dropwise with stirring in the course of 15 minutes; the reaction mixture 
is then initially stirred at 0.degree. C.-10.degree. C. for one hour, then 
at 20.degree. C. for a further hour. The reaction is terminated by adding 
1,000 ml of water. The separated organic phase is worked up by 
distillation. In addition to vinylidene chloride and xylene. 305 g (=94% 
of theory) of 2,2-bis-(o-xylyl)-propane (b.p.: 152.degree. C.-155.degree. 
C./0.15 mbar) are obtained. 
EXAMPLE 12 
a) A solution of 235 g (=1.12 mol) of 1,1,1,3-tetrachloro-3-methyl-butane 
in 800 g (8.7 mol) of toluene is added with stirring and cooling at 
-50.degree. C. in the course of 20 min. to a suspension of 40 g of 
AlCl.sub.3 in 100 ml of dichloromethane. After stirring at -50.degree. C. 
for 40 minutes, water is added to the reaction mixture and the organic 
phase is separated off. After washing and drying the organic phase, this 
is freed from solvent and excess toluene in a rotary evaporator. 299 g of 
crude product are obtained, which contains 82% (=245 g=82.5% of theory) of 
1,1,1-trichloro-3-methyl-3-p-tolyl-butane according to GC analysis. The 
pure compound (b.p.: 89.degree. C./0.04 mbar) is obtained by distillation 
of the crude product. 
b) Use of the 1,1,1-trichloro-3-methyl-3-p-tolylbutane for the preparation 
of 1-[4-fluoro-3-phenoxyphenyl]-4-methyl-4-p-tolyl-pentane. 
.alpha.) The crude product from stage a) is mixed, with vigorous stirring, 
with a solution of 300 g of sodium hydroxide in 240 ml of water with the 
addition of 3 g of tetrabutylammonium bromide and the mixture is heated to 
100.degree. C. with stirring for 20 hours. The reaction mixture is 
extracted with dichloromethane; the combined extracts are washed with 
dilute hydrochloric acid and, after drying, worked up by distillation. 140 
g (=78.8% of theory of 1-chloro-3-methyl-3-p-tolyl-butine (b.p.: 
114.degree.-115.degree. C./20 mbar) are obtained. 
.beta.) A solution of 96.5 g (0.5 mol) of 1-chloro-3-methyl-p-tolyl-butine 
in 500 ml of absolute methanol is heated to reflux temperature with 
stirring for 72 hours after adding 90 g of activated zinc dust. The 
reaction mixture is then concentrated in a rotary evaporator; the residue 
is taken up using dilute hydrochloric acid and dichloromethane and the 
organic phase is separated off. The organic phase is worked up by 
distillation; 66 g (=83% of theory) of 3-methyl-3-p-tolyl-butine (b.p.: 
90.degree.-92.degree. C./22 mbar) are obtained. 
.gamma.) A solution of 0.2 mol of butyllithium in hexane is added at 
-70.degree. C. with stirring to a solution of 32 g (0.2 mol) of 
3-methyl-3-p-tolyl-butine in 150 ml of absolute tetrahydrofuran and then a 
solution of 43.2 g (0.2 mol) of 4-fluoro-3-phenoxy-benzaldehyde in 100 ml 
of tetrahydrofuran is added at -30.degree. C. The reaction mixture is 
warmed to room temperature and stirred at this temperature for 12 hours. 
The solvent is then removed in vacuo and the residue is taken up using 
water and dichloromethane. The organic phase is separated off and worked 
up by distillation. 72 g of crude product are obtained, which consists 
essentially of 
1-[4-fluoro-3-phenoxyphenyl]-3-methyl-3-p-tolyl-pent-2-in-1-ol according 
to GC-MS analysis (by-product: 4-fluoro-3-phenoxyphenyl 
3-methyl-3-p-tolyl-butin-1-yl ketone). 
.delta.) The crude product is dissolved in 2,000 ml of methanol and the 
solution is hydrogenated at 80.degree. C. and at a hydrogen pressure of 40 
bar in a stirring autoclave after adding 7 g of Pd-C (5%). After 
separating off the Pd catalyst and concentrating the reaction solution in 
a rotary evaporator, 69 g of a crude product are obtained which contains 
93% (=64.2 g=88.6% of theory) of 
1-[4-fluoro-3-phenoxyphenyl]-4-methyl-4p-tolyl-pentane (n.sub.D.sup.20 : 
1.5629) according to GC-MS analysis. 
EXAMPLE 13 
a) A mixture of 61 g (0.5 mol) of phenetole and 105 g (0.5 mol) of 
1,1,1,3-tetrachloro-3-methyl-butane is added slowly with stirring at 
0.degree. C. to a suspension of 66.5 g (0.5 mol) of AlCl.sub.3 in 100 ml 
of dichloromethane. After stirring for 4 hours, 1,000 ml of water are 
added to the reaction mixture with ice-cooling. The mixture is extracted 
several times with dichloromethane and, after drying, the combined 
extracts are worked up by distillation. 30 g (=20% of theory) of 
1,1,1-trichloro-3-p-ethoxyphenyl-3methyl-butane (b.p.: 
145.degree.-150.degree. C./0.1 mbar) are obtained in addition to unreacted 
starting material. 
b) Use of the 1,1,1-trichloro-3-p-ethoxyphenyl-3-methylbutane for the 
preparation of 
1-[4-fluoro-3-phenoxy-phenyl]-4-[p-ethoxyphenyl]-4-methyl-pentane. 
.alpha.) The mixture of 1,1,1-trichloro-3-p-ethoxyphenyl-3-methyl-butane 
obtained in step a), 25 g of potassium tert.-butoxide and 200 ml of 
dimethylformamide is heated at 85.degree. C. with stirring for 12 hours. 
tert.-Butanol and dimethylformamide are then removed from the reaction 
mixture by vacuum distillation. The residue is taken up in water and 
dichloromethane and the organic phase is separated off. 20 g (=89% of 
theory) of 1-chloro-3-epoxyphenyl-3-methyl-butine (b.p.: 
98.degree.-100.degree. C./0.7 mbar) are obtained by vacuum distillation of 
the organic phase. 
.beta.) 20 g of 1-chloro-3-ethoxyphenyl-3-methyl-butine are added to a 
suspension of 20 g of activated zinc powder in 120 ml of methanol. The 
mixture is heated at reflux temperature with stirring for 24 hours. The 
methanol is then removed by distillation, the residue is taken up in 
dilute hydrochloric acid and dichloromethane and the organic phase is 
separated off. Distillation of the organic phase yields 14 g (=83% of 
theory) of 3-[p-ethoxyphenyl]-3-methyl-1-butine (b.p.: 
71.degree.-73.degree. C./0.01 mbar). 
.gamma.) 0.01 mol of a solution of butyllithium in hexane is added at 
-30.degree. C. with stirring to 1.9 g (0.01 mol) of 
3-[p-ethoxyphenyl]-3-methyl-1-butine in 10 ml of absolute tetrahydrofuran. 
After stirring for 3 hours, a solution of 2.2 g (0.01 mol) of 
4-fluoro-3-phenoxy-benzaldehyde in 10 ml of tetrahydrofuran is added to 
the reaction mixture. The reaction mixture is warmed to room temperature 
and, after stirring at this temperature for 5 hours, water and 
dichloromethane (100 ml each) are added. The organic phase is separated 
off and concentrated in vacuo. 3.6 g of crude product are obtained, which 
contains 85% of 
1-[4-fluoro-3-phenoxy-phenyl]-4-[p-ethoxyphenyl]-4-methyl-pent-1-in-1-ol 
(in addition to 7% of the corresponding ketone) according to GC-MS 
analysis. The crude product is catalytically hydrogenated under the 
conditions described in Example 8 .delta.). 3 g of 
1-[4-fluoro-3-phenoxy-phenyl]-4-[p-ethoxyphenyl]-4-methyl-pentane (89% 
pure according to GC-MS analysis=2.7 g=69% of theory) are obtained. The 
compound is obtained pure by chromatography on silica gel (n.sub.D.sup.20 
: 1.5580).