Title of Invention

PROCESS FOR PREPARING BIPHENYL TYPE AROMATIC THIOETHERS

Abstract ABSTRACT IN/PCT/2001/00873/CHE Process for preparing biphenyl type aromatic thioethers The invention concerns a method for preparing aromatic diphenyl thioethers. More particularly the invention concerns the preparation of 4-chloro-4 -thiomethyldiphenylether. The inventive method for preparing an atomatic diphenyl thioether is characterized in that it consists in reacting in an aqueous medium a diazonium salt of an aromatic diphenyl compound with a disulphide sulphur compound, in the presence of an efficient amount of a coupling catalyst.
Full Text PROCESS FOR PREPARING BIPHENYL TYPE AROMATIC THIOETHERS
The present invention relates to a process for preparing biphenyl type aromatic thioethers.
More precisely, the invention relates to the preparation of an aromatic compound comprisii] a concatenation of at least two phenyl groups at least one of which carries a thioether group.
More particularly, the invention relates to the preparation of 4-chloro-4 thiomethyldiphenyether.
When a flmctional group is to be introduced into a biphenyl typ6 molecule, there is problem with introducing a functional group into only one of the benzene rings.
The present invention aims to provide a process that consists of introducing at least on :hioether group into one of the^phenyl groups.
It has now been discovered, and this forms the subject matter of the present invention, . )rocess for preparing a biphenyl type aromatic thioether, characterized in that a diazonium salt of; )iphenyl type aromatic compound is reacted with a disulphide type sulphur-containing compound ii in aqueous medium in the presence qf an effective quantity of a coupling catalyst.
The term "biphenyl type aromatic thioether" means a concatenation of two phenyl group: onnected together wherein at least one of the benzene rings carries a thioether function.
In a preferred variation of the process of the invention, the thioether is prepared using £ rocess that associates preparation of the diazonium salt from the corresponding aromatic amim len, without separation, carrying out the reaction with the sulphur-containing compound.
In accordance with the process of the invention, a biphenyl type aromaticamine ^n be used 3 the starting compound; in a first step, it is transformed into a diazonium salt.
The term "biphenyl type aromatic amine" means a concatenation of two phenyl groups jnnected together wherein at least one of the benzene rings carries an amine fimction.
The starting aromatic amine can be represented by the following general formula (I):


I'pe starting substrate, at least one of the 5 hydrogen atoms of the aromatic ring can be replaced by n atom other than a hydrogen atom. In particular, it can be a halogen atom, carbon, oxygen or itrogen.
Group R| represents a hydrogen atom or any other group R.

Group R can have any nature provided that it does not interfere with the diazotisation reaction.
Non-limiting examples of substituents that can be cited are given below:
• a linear or branched alkyl group, preferably containing 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms;
• a linear or branched alkenyl group preferably containing 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms;
• a linear or branched halogenoalkyl group preferably containing 1 to 4 carbon atoms, and 1 to 9 halogen atoms;
• a cycloalkyl group containing 3 to 7 carbon atoms, preferably a cyclohexyl group;
• a phenyl group;
• a hydroxyl group;
• a NO2 group;
• a R3-O- alkoxy group or R3-S- thioether group where R3 represents a linear or branched alkyl group containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, or a phenyl group;
• a -N-(R2)2 group where groups R2, which may be identical or different, represent a hydrogen atom, a linear or branched alkyl group containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, or a phenyl group;
• a -NH-CO-R2 group where R2 has the meaning given above;
• a carboxyl group or R2-O-CO- derivative, where group R2 has the meaning given above;
• an acyloxy or aroyloxy group R3-CO-O-, where group R3 has the meaning given above;
• a B(OR3)2 group, where group R3 has the meaning given above;
• a halogen atom, preferably a fluorine atom;

• a CF3 group;
• two groups R can together form an alkylenedioxy group containing 1 to 4 atoms in the alkylene group, preferably a methylenedioxy or ethylenedioxy group.
Preferred groups R that can be cited are a halogen atom, preferably a fluorine, chlorine or bromine atom or a halogenoalkyl group, preferably perfluoroalkyl; a hydroxyl group; an alkyl or alkoxy group containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms; an amino group or an amino group substituted with one or two alkyl groups containing 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms.
Preferred compounds are those with formula (I) where Ri represents a fluorine atom or a chloriAe atom and Z represents an oxygen atom.
,^ In accordance with the process of the invention, in a first step the diazonium salt of the biphenyl type aromatic amine preferably with formula (I) is prepared.
To this end, to transform the amino group into a diazonium group, the starting substrate is reacted with an acid. While it is possible to use an acid such as sulphuric acid, it is preferable to use 1 hydrogen acid to put the amine group into the halohydrate salt form.
V Thus, the starting substrate preferably with formula (I) is preferably reacted with lydrochloric acid or hydrobromic acid.
5^ ■ The quantity of acid used is such that the mole ratio between the number of H"^ ions and the lumber of moles of substrate is in the range 2.0 to 2.5, preferably in the range 2.0 to 2.2. ) In the next step, the diazonium salt is prepared by reacting the biphenyl type aromatic ainine n the halohydrate form with a diazotisation reactant that is any source of N0+.
Thus it is possible to start from nitrogen dioxide NO2, nitrogen trioxide N2O3, nitrogen jtroxide N2O4, nitric oxide NO associated with an oxidising agent such as nitric acid, nitrogen ioxide or oxygen. When the reactant is a gas under the reaction conditions, it is bubbled into the ledium.

It is also possible to use a nitrous acid, a nitrosyl sulphide or a nitrose or a nitrous salt,
preferably an alkali metal salt, more preferably a sodium salt. |
i I
It is also possible to use alkyl nitrites, more particularly those with formula (II): j

in which formula (II), Ra represents a linear or branched alkyl group containing 1 to 12 i
carbon atoms, preferably 1 to 4 carbon atoms. f'
i Advantageously, sodium nitrite is used.
The quantity of diazotisation reactant used can vary widely. When it is expressed as the mole ratio of the aromatic amine/ diazotisation reactant defined as NO"^, it is at least equal to the stoichiometric quantity but preferably, it is used in an excess of up to 120% of the stoichiometric quantity, preferably in the range 100% to 120%.
Regarding the concentration of the aromatic amine substrate in the reaction medium, it is preferably in the range 0.5 to 2.5 mol/I, more preferably about 1 mol/1.
The amine halohydrate is prepared by simply mixing the starting amine and the acid.
The reaction is advantageously carried out at a temperature in the range 50°C to 1QQ°C.
The diazotisation reactant is then added, preferably slowly in fractions or continuously.
Regarding the temperature of the diazotisation reaction, this is generally a low temperature, advantageously in the range -10°C to 20°C, preferably in the range 0°C to 10°C.
In the process of the invention, the sulphur-containing compound is reacted with the

in which formula (III):

• A represents a halogen atom X, preferably a chlorine or bromine atom, a HSO4' group or a S04~ group;
• Ri and Z have the meanings given above;
• n equals 1 or 2.
The sulphur-containing compound used preferably has the following formula (IV):
R4-S-S-R5 (IV)
in said formula (IV):
• R4 and R5, which may be identical or different, represent a hydrocarbon group containing
1 to 24 carbon atoms, which can be a saturated or unsaturated, linear or branched
aliphatic acyclic group; a saturated, unsaturated or aromatic, monocyclic or polycyclic
carbocyclic or heterocyclic group, or a linear or branched, saturated or unsaturated
aliphatic group carrying a cyclic substituent.
Th^ sulphur-containing compound used in the process of the invention has formula (IV)
where R4 and R5 can have a number of meanings. Different, non-limiting, examples will be given
below.
( With compounds with formula (IV), R4 and R5 preferably represent a saturated or
unsaturated, linear or branched acyclic aliphatic group preferably containing 1 to 24 carbon atoms,
i comprising one or more unsaturated bonds in the chain, generally 1 to 3 unsaturated bonds which
I
I
\ may be simple double bonds or conjugated double bonds or triple bonds.
More particularly, R4 and R5 represent a linear^r branched alkyl, alkenyl, or alkadienyl group preferably containing 1 to 12 carbon atoms.
R4 and R5 represent a linear or branched halogenoalkyj_ group preferably containing 1 to 12 carbon atoms, more preferably 1 to 4 carbon atoms, and 3 to 25 halogen atoms. The hydrocarbon chain can optionally be:

/
• interrupted by a functional atom or group; groups B cited above may be cited in this respect;
• and/or carry one of the following substituents: -OH, -COR3, -COOR2, -CHO, -CN, -NO2, -X, -CF3
where groups R2, which may be identical or different, and group R3 have the meanings given above.
Groups R4 and R5 can represent a halogenoalkyl group, preferably perhalogenoalkyi, or a halogenoalkenyl group.
In formula (IV), the saturated or unsaturated linear or branched aliphatic acyclic group can optionally carry a cyclic substituent. The term "cycle" means a saturated, unsaturated or aromatic carbocyclic or heterocyclic cycle.
The aliphatic acyclic group can be bonded to the cycle by a covalent bond or by a group B as cited above.
Examples of cyclic substituents that can be envisaged are cycloaliphatic, aromatic or heterocyclic substituents, in particular cycloaliphatic substituents containing 6 carbon atoms in the cycle or benzenic substituents, such cyclic substituents themselves optionally carrying one or more substituents.
Examples of such groups that can be mentioned are the benzyl group.
In general formula (IV), R4 and R5 can represent a monocyclic carbocyclic group. The number of carbon atoms in the cycle can vary widely from 3 to 8 carbon atoms, but is preferably 5 or 6 carbon atoms.
The carbocyle can be saturated or may comprise 1 or 2 unsaturated bonds in the cycle, preferably 1 or 2 double bonds.
Preferred examples of groups R4 and R5 that can be cited are cyclohexyl or cyclohexene-yl groups.

f
When R4 or R5 represents a saturated or unsaturated monocyclic carbocyclic group, one or more of the carbon atoms of the cycle may be replaced by a heteroatom, preferably oxygen, nitrogen or sulphur or by a functional group, preferably carbonyl or ester, leading to a monocyclic heterocyclic compound. The number of atoms in the cycle can be in the range 3 to 8 atoms, preferably 5 or 6 atoms.
Groups R4 and R5 can also be polycyclic carbocyclic, preferably bicyclic, meaning that at least two cycles have two carbon atoms in common. With polycyclic groups, the number of carbon atoms in each cycle is in the range 3 to 6: the total number of carbon atoms is preferably 7.
Groups R4 and R5 can also be polycyclic heterocyclic, preferably bicyclic, which means that at least two cycles have two atoms in common. In this case, the number of atoms in each cycle is in the range 3 to 6, more preferably 5 or 6.
Groups R4 and R5 preferably represent an aromatic carbocyclic group, in particular benzenic or a concatenation of 2 or 3 benzene rings separated by atoms or groups B as defined above.
Examples of groups R4 and R5 with formula (IV) that can more particularly be mentioned are phenyl groups.
R4 and R5 can also represent a polycyclic aromatic hydrocarbon group; the cycles can between them form ortho-condensed or ortho- and peri-condensed systems. More particularly, the group can be the naphthyl group.
In general formula (IV), R4 and R5 can also represent an aromatic heterocyclic group in particular comprising 5 or 6 atoms in the cycle, wherein 1 or 2 are heteroatoms such as nitrogen, sulphur or oxygen.
Illustrative examples of heterocyclic groups that can be cited are tetrahydrofuryl, tetrahydrothienyl, pyrrolidinyl, furyl, thienyl, pyrrolyl and pyridyl.

R4 and R5 can also represent a polycyclic aromatic heterocyclic group defined as either a group constituted by at least two aromatic or non aromatic heterocycles containing at least one heteroatom in each cycle and forming between them ortho- or ortho- and peri-condensed systems, or a group constituted by at least one aromatic or non aromatic hydrocarbon cycle and at least one aromatic or non aromatic heterocycle forming between them ortho- or ortho- and peri-condensed systems.
Illustrative examples of polycylic groups that can be cited are: isoquinolyl^ quiriolyl, naphthyridinyl, benzofuranyl and indolyl.
It should be noted that if group R4 and R5 comprises a cycle, that cycle may carry a substituent. The nature of the substituent is irrelevant as long as it does not interfere with the desired product. The substituents are of the same nature as R.
Preferred examples of groups R4, R5 that can be cited are linear or branched alkyl groups containing 1 to 4 carbon atoms, 2-carboxyethyl, cyclohexyl, phenyl, benzyl, benzoyl, pyridyl, etc..
The process is readily carried out using a number of sulphur-containing compounds.
Preferred examples of disulphide type sulphur-containing compounds that can b mentioned are:
• dimethyldisulphide;
• diethyldisulphide;
• di-n-propyldisulphide;
• diisopropyldisulphide;
• di-n-butyldisulphide;
• diisobutyldisulphide;
• di-sec-butyldisulphide;
• di-tert-butyldisulphide;

diisoamyldisulphide; di-n-hexyldisulphide; di-tert-heptyldisulphide; di-n-undecyldisulphide; distearyldisulphide; diallyldisulphide; dicyclohexyldisulphide; diphenyldisulphide; dibenzyldisulphide dibenzoyldisulphide; dithiopyridine; dithioglycolic acid.
Preferred compounds from the list cited above are dialkyldisulphides preferably )ntaining 1 to 4 carbon atoms in the alkyl portion.
The quantity of sulphur-containing compound is such that said mole ratio is preferably in e range 1 to 1.5.
The coupling reaction is carried out in an aqueous medium. The quantity of water •esent in the reaction medium generally represents 100%) to 500%) by weight of the aromatic amine. In a variation, the process of the invention consists of adding an organic solvent which is ert under the reaction conditions.
Examples of organic solvents that can be cited are saturated aliphatic monocarboxylic ;ids, more particularly formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, jntanoic acid and 2-methylbutanoic acid.
Acetic acid is the preferred saturated aliphatic monocarboxylic acid.

It is also possible to use a solvent such as acetone or dimethylformamide.
The quantity of organic solvent used, expressed as the weight of starting amine, is advantageously in the range 100% to 1000%, preferably in the range 200% to 500%.
In the process of the invention, the diazonium salt, preferably with formula (III), is reacted with the sulphur-containing compound, preferably with formula (IV): the reaction is carried
^- *u f V * 1 * C4TAL.VST
out m the presence of a couplmg catalyst. —
The coupling catalyst is a catalyst comprising at least one metallic element selected from the 4"^ and 5'*' period of groups IIIA, IV A, VA, VIA, VIIA, VIII, IB and IIB of the periodic table.
Preferred metals that can be cited are: copper, iron, cobalt, nickel, palladium and platinum.
The elements are defined in the periodic table published in the "Bulletin de la Societe Chimique de France, n°l (1966).
The metallic elements can also be supplied in the form of a zero metal or an inorganic derivative such as an oxide or hydroxide. It is possible to use a mineral salt, preferably a nitrate,
sulphate, oxysulphate, halide, oxyhalide, silicate, carbonate or an organic derivative, preferably ai
j
cyanide, oxalate, acetylacetonate; an alcoholate, more preferably a methylate or ethylate; or a^ carboxylate, more preferably an acetate. It is also possible to use complexes, in particular chlorine-containing or cyanide-containing complexes of said metals and/or alkali metals, preferably sodium or potassium, or ammonium.
More specific examples of palladium catalysts that can be cited are palladium (II) chloride, hydrated palladium (II) nitrate, dihydrated palladium (II) sulphate, palladium (II) acetate, ammonium tetrachloropalladate (II), potassium hexachloropalladate (IV), and palladium (II) tetrakisphenylphosphine.
Platinum catalysts that can be mentioned include platinum (II) chloride, ammonium tetrachlorplatinate (II), ammonium hexachloroplatinate (IV), hydrated sodium tetrachloroplatinate

(IV), hexahydrated sodium hexachloroplatinate (IV), potassium hexachloroplatinate (IV), and hexahydrated chloroplatinic acid.
Nickel or cobalt catalysts that can be cited include nickel (II) bromide and chloride and cobalt (II) chloride or bromide.
The catalyst of choice used in the process of the invention is copper-based.
Examples of catalysts that can be cited are copper metal or organic or inorganic copper I or copper II compounds.
Preferably, catalysts based on copper 0 and I are used.
Non limiting examples of copper compounds that can be cited are cuprous bromide, cupric bromide, cuprous iodide, cuprous chloride, cupric chloride, basic copper II carbonate, cuprous nitrate, cupric nitrate, cuprous sulphate, cupric sulphate, cuprous sulphite, cuprous oxide, cuprous acetate, cupric acetate, cupric trifluoromethylsulphonate, cupric hydroxide, copper I methylate, copper II methylate, and chlorocupric methylate with formula ClCuOCHs.
The quantity of catalyst used, expressed as the ratio of the weight of diazonium salt is generally in the range 0.1 to 20 mole %, preferably 1% to 10%.
The coupling reaction between the diazonium salt preferably with formula (III) and the sulphur-containing compound is advantageously carried out at a temperature in the range 0°C to 120°C, preferably in the range 80°C to 100°C.
In general, the reaction is carried out at atmospheric pressure, but lower or higher pressures may also be suitable. Autogenous pressure is employed when the reaction temperature is higher than the boiling temperature of the reactants and/or products.
In a preferred variation of the process of the invention, the process of the invention is carried out in a controlled atmosphere of inert gas. A rare gas atmosphere can be established, preferably argon, but nitrogen is more economical.

The reaction is continued until the diazonium salt is completely transformed. The reaction progress can be monitored using any conventional analytical technique such as gas chromatography or high performance liquid chromatography.
The reaction period is generally short, of the order of 30 min to 2 hours.
From a practical viewpoint, the two reactants are brought together in any order. In a preferred variation, the sulphur-containing compoimd is preferably added to the diazonium salt, followed by the catalyst.
At the end of the reaction, two phases are obtained; the aqueous phase comprises all of the salts formed and the organic phase comprises, in addition to any excess reactants, the desired compound which preferably has formula (VI):

in which formula (VI), R1, R4 and Z have the meanings given above.
The desired product is recovered from the organic phase using conventional techniques. By way of illustration, it is possible to add an organic solvent, for example isopropyl ether or an alkane such as methylcyclohexane, to extract all of the organic compounds and then, from this organic phase, to separate the compound using the usual separation techniques such as distillation or crystallisation from a suitable solvent, preferably an alcohol, more particularly methanol or isopropanol.
The following examples are given by way of illustration and are in no way limiting in nature.
The following abbreviations are used in the examples:


RR = number of moles of 4-chloro-4'thiomethvldiphenvlether formed. %
Number of moles of 4-chloro-4'aminodiphenylether introduced
EXAMPLE 1
2.20 g (10 mmoles) of 4-chloro-4'-aminodiphenylether, 8 ml of water and, with stirring, 2.33 g (23 mmoles) of 36% hydrochloric acid were charged into a 50 ml double envelope reactor.
It was heated to 90°C and the mixture became homogeneous.
This temperature was maintained for 45 minutes then it was cooled to 10°C.
0.69 g (10 mmoles) of an aqueous 30% sodium nitrite solution was poured in over two hours using a syringe driver.
The diazonium salt was added dropwise to a mixture of 0.82 g of dimethyldisulphide and 5 ml of water and 31 mg of copper metal in a 100 ml reactor at 50°C.
15 ml of isopropyl ether was added.
The reactor was emptied and the organic phase was washed with 100 ml of water and 100 ml of 10% sodium bisulphite in water and again with 100 ml of water.
The organic phase was concentrated under reduced pressure of 2 mbars, at 50°C for 1 hour.
1.38 g of 4-chloro-4'-thiomethyldiphenylether was obtained, corresponding to a degree of transformation of 100^ and a yield RR of 55%,. '
The product obtained could be purified by crystallisation from methanol.
EXAMPLES 2 TO 14
The above example was repeated, changing the nature of the catalyst.
The quantity of product formed was determined by gas chromatographic analysis.
The results are shown in Table (I).


165 g of Cl-Ph-0-Ph-NH2 (0.75 moles) was charged into a 2.0 litre three-necked flask provided with a thermometer, a dropping funnel, a coolant surmounted by an argon reservoir (balloon) and maintained under an inert atmosphere with vigorous magnetic stirring. 300 ml of acetic acid was then added.
The assembly was heated to 80°C then 82.5 g of a concentrated aqueous hydrochloric acid solution (37%) was slowly added.
The reaction medium was stirred for about 45 min at 80°C.
The temperature was allowed to return to 65°C with stirring.
2.13 g of CuCh was then added to the reaction medium, followed by 132 ml of Me2S2.
Then an aqueous NaNOi solution (solution of 54 g in 120 ml of H2O) was added using the dropping funnel.
When no more gas had been released, the temperature was returned to ambient temperature and the reaction medium was diluted with 360 ml of water. Two phases appeared.
500 ml of methylcyclohexane was added and the two phases were separated.

The aqueous phase was extracted again with methylcyclohexane (500 ml).
After evaporating off the methylcyclohexane, 242 g of a brown oil was recovered. The crude product was recrystallised to produce 124 g of pink-white crystals (yield: 66%; purity: 97.2%, determined by gas chromatography; and MPt = 56.0°C).
A second recrystallisation was possible.



WE CLAIM:
1. A process for preparing a biphenyl type aromatic thioether, characterized in that a diazonium salt of a biphenyl type aromatic compound is reacted with a disulphide type sulphur containing compound in an aqueous medium in the presence of an effective quantity of a coupling catalyst.
2. The process according to claim 1, wherein it consists of preparing the diazonium salt from the corresponding aromatic amine then, without separation, carrying out the reaction with the sulphur-containing compound.
3. The process according to claim 1 or claim 2, wherein the aromatic starting amine has general formula (I):

in which
R1 represents a hydrogen atom or a substituent R selected from:
a linear or branched alkyl group containing 1 to 6 carbon atoms; a linear or
branched alkenyl group containing 2 to 6 carbon atoms:
a linear or branched halogenoalkyl group, preferably containing 1 to 4
carbon atoms, and 1 to 9 halogen atoms;
a cycloalkyl group containing 3 to 7 carbon atoms;
a phenyl group;
a hydroxy 1 group;

a NO2 group;
a R3-O- alkoxy group or R3-S- thioether group where R3 represents a linear
or branched alkyl group containing 1 to 6 carbon atoms, or a phenyl group;
a -N-(H2)2 group where groups R2, which may be identical or different,
represent a hydrogen atom, a linear or branched alkyl group containing 1 to
6 carbon atoms, or a phenyl group;
a -NH-CO-R2 group where R2 has the meaning given above;
a carboxyl group or R2-O-CO derivative where group R2 has the meaning
given above;
an acyloxy or arcyloxy group R3-CO-O-, where group R3 has the meaning
given above;
a B(OR3)2 group, where group R3 has the meaning given above; a halogen
atom;
a CF3 group;
two groups R can together form an alkylenodioxy group containing 1 to 4
atoms in the alkylene group;
Z represents;
a covalent bond;
an alkylene or alkylideno group containing 1 to 4 carbon atoms;
a group B which may be one of the following atoms or groups:


i
in which formulae, R2 represents a hydrogen atom or an alkyl group containing 1 to 6 carbon atoms, or a phenyl group,
4. The process according to claim 3, wherein the aromatic starting amine has general formula (I) in which Ri represents a hydrogen atom or any other group selected from:
a linear or branched alkyl group, preferably containing 1 to 4 carbon atoms; a linear or branched alkenyl group containing 2 to 4 carbon atoms; a cyclohexyl group;
a R3-O- alkoxy group or R3-S- thioether group where R3 represents a linear
or branched alkyl group containing 1 to 6 carbon atoms, preferably 1 to 4
carbon atoms, or a phenyl group;
a -N-(R2)2 group where groups R2, which may be identical or different,
represent a hydrogen atom, a linear or branched alkyl group containing 1 to
4 carbon atoms, or a phenyl group;
a -NH-CO-R2 group where R2 has the meaning given above;
a carboxyl group or R2-O-CO- derivative where group R2 has the meaning
given above;
an acyloxy or aroyloxy group R3-CO-O- where group R3 has the meaning
given above;
a B(OR3)2 group, where group R3 has the meaning given above;
a fluorine atom;
two groups R can together form a methylenedioxy or ethylenedioxy group;
Z represents: a covalent bond;

an methylene or isopropylidene group;
a group B which may be one of the following atom; or groups:

in which formulae R2 represents a hydrogen atom or an alkyl group containing 1 to 6 carbon atoms, or a phenyl group.
5. A process according to claim 4, wherein the aromatic starting amine
has general formula (I) in which group R is a fluorine, chlorine or bromine
atom, or a perfluoroalkyl group; a hydroxy 1 group; an alkyl or alkoxy group
containing 1 to 4 carbon atoms; an amino group or an amino group
substituted by one or two alkyl groups containing 1 to 4 carbon atoms.
6. The process according to any one of claims 1 to 5, wherein the aromatic
starting amine has general formula (I) where Ri represents a fluorine atom or
chlorine atom and Z represents an oxygen atom.
7. The process according to any of claims 1 to 6, wherein the halohydrate of
the biphenyl type aromatic amine preferably with formula (I) is prepared by
reacting said amine with a hydrogen acid, preferably hydrochloric acid or
hydrobromic acid.

8. The process according to claim 7, wherein the quantity of acid used is
such that the mole ratio between the number of H+ ions and the number of
moles of substrate is in the range 2.0 to 2.5, preferably in the range 2.0 to
2.2.
9. The process according to claim 7 or 8, wherein the reaction between the
aromatic amine and the hydrogen acid is carried out at a temperature in the
range 50°C to 100°C.
10. The process according to anyone of claims 1 to 9, wherein the diazonium salt is prepared by reacting the biphenyl type aromatic amine in the halohydrate form with a diazotisation reactant that is any source of NO"^.
11. The process acoording to claim 10, wherein the diazotisation reactant is any source of NO^, preferably nitric oxide NO associated with an oxidising agent, nitrogen dioxide NO2, nitrogen trioxide N2O3, nitrogen tetroxide N2O4, nitrous acid; nitrosyl sulphate or a nitrous salt, preferably an alkali metal salt, more preferably sodium, or any alkyl nitrite.
12. The process according to claim 11, wherein the quantity of diazotisation reactant used, expressed as the mole ratio of the aromatic amine/diazotisation reactant defined as NO^, is in the range 100% to 120%.
13. The process according to any one of claims 10 to 12, wherein the temperature of the diazotisation reaction is in the range -10°C to 20*'C, preferably in the range 0°C to 10°C.
14. The process according to any one of claims 10 to 13, wherein the diazonium salt obtained preferably has formula (III):


in which formula (III):
X represents a halogen atom X, preferably a chlorine or bromine atom, a HS04,' group or a S04= group;
R] and Z have the meanings defined in anyone of claims 3 to 6; n equals 1 or 2.
15. The process according to claim 1 or claim 2, wherein the sulphur-containing compound used has the following formula (IV):
R4-S-S-R5 (IV)
in said formula (IV):
R4 and R5, which may be identical or different, represent a hydrocarbon group containing 1 to 24 carbon atoms, which can be a saturated or unsaturated, linear or branched acyclic aliphatic group; a saturated, unsaturated or aromatic monocyclic or polycyclic carbocyclic or heterocyclic group; or a linear or branched, saturated or unsaturated aliphatic group carrying a cyclic substituent.

16. The process according to claim 15, wherein the sulphur-containing compound has general formula (IV) where R4 and R5 represent a saturated or unsaturated, linear or branched acyclic aliphatic group preferably containing 1 to 24 carbon atoms, saturated or comprising one or more unsaturated bonds in the chain, generally 1 to 3 unsaturated bonds which may be simple or conjugated double bonds, or triple bonds.
17. The process according to claim 15 or claim 16, wherein the sulphur-containing compound has general formula (IV) where R4 and R5 represent a linear or branched alkyl, alkenyl or alkadienyl group preferably containing 1 to 12 carbon atoms; the hydrocarbon chain can optionally be:
interrupted by an atom or a functional group B as defined in claim 3;
and/or carry one of the following substituents: OH, -COR3 -COOR2, -CHO, -CN, -NO2 -X, -CF3;
in which formulae, groups R2, may be identical or different, and group R3 have the meanings defined above.
18. The process according to anyone of claims 15 to 17, wherein the 1
sulphur-containing compound has general formula (IV) where R4 and R5
represent a linear or branched halogenoalkyl group preferably containing 1 to 12 carbon atoms and more preferably 1 to 4 carbon atoms, and 3 to 25 halogen atoms.
19. The process according to an one of claims 15 to 18, wherein the sulphur-
containing compound has general formula (IV) where R4 and R5 represent a
saturated or unsaturated, linear or branched acyclic aliphatic group carrying
a cyclic substituent, preferably a benzene ring: the acyclic aliphafic group

may be bonded to the ring via a covalent bond or by a group B as defined in claim 3.
20. The process according to claim 15, wherein the sulphur-containing
compound has general formula (IV) in which R4 and R5 represent:
a monocyclic group that is saturated or contains 1 or 2 unsaturated bonds in the cycle; the number of carbon atoms in the cycle may be in the range 3 to 8 carbon atoms, preferably 5 or 6; apolycyclic carbocyclic group, preferably bicyclic; the number of carbon atoms in each cycle is in the range 3 to 6; the total number of carbon atoms preferably being equal to 7.
21. The process according to claim 15, wherein the sulphur-containing compound general formula (IV) in which groups R4, and R5 represent an aromatic carbocyclic group, in particular a benzene ring or a concatenation of 2 or 3 benzene rings separated by atoms or groups B as defined in claim 3.
22. The process according to claim 15, wherein the sulphur-containing compound has general formula (IV) where R4 and R5 represent:
an aromatic heterocyclic group containing 5 or 6 atoms in the ring, 1 or 2 of which are heteroatoms; a polycyclic aromatic carbocyclic or heterocyclic group.
23. The process according to any one of claims 15 to 22, wherein the
sulphur-containing compound has general formula (IV) where groups R4
and R5 represent a linear or branched alkyl group containing 1 to 4 carbon
atoms, or a 2-carboxyethyl, cyclohexyl, phenyl, benzyl, benzoyl or pyridyl
group.

24. The process according to claims 15 to 23, wherein the sulphur-containing compound has general formula (IV) in which R4 and R5 are identical.
25. The process according to claim 15, wherein the sulphur-containing compound having general formula (IV) is a disulphide type compound selected from:
dimethyldisulphide;
diethyldisulphide;
di-n-propyldisulphide;
diisopropyldisulphide;
di-n-butyldisulphide;
diisobutyldisulphide;
di-sec-butyldisulphide;
di-tert-butyldisulphide;
diisoamyldisulphide;
di-n-hexyldisulphide;
di-tert-heptyldisulphide;
di-n-undecy Idisulphide;
distearyldisulphide;
diallyldisulphide;
dicyclohexyldisulphide;
diphenyldisulphide;

dibenzyldisulphide; dibenzoy Idi sulphide; dithiopyridine; dithioglycolic acid.
26. The process according to anyone of claims 1 to 26, wherein the coupling catalyst is a catalyst comprising at least one metallic element selected from the 4* and 5*' period of groups IIIA, IVA, VA, VIA, VIIA, VIII, IB and IIB of the periodic table.
27. The process according to claim 26, wherein the coupling catalyst is a catalyst comprising at least one of the following metallic elements: copper, iron, cobalt, nickel, palladium and platinum.
28. The process according to claims 26 or 27, wherein the coupling catalyst is a catalyst in which the metallic element is supplied in form of a zero metal or an inorganic derivative such as an oxide or hydroxide or a mineral salt, preferably a nitrate, sulphate, oxysulphate, halide, oxyhalide, silicate, carbonate or an organic derivative, preferably a cyanide, oxalate or acetylacetonate; an alcoholate, more preferably a methylate or ethylate; or a carboxylate, more preferably an acetate.
29. The process according to anyone of claims 26 to 28, wherein the catalyst is copper metal or an organic or inorganic copper I or copper II compound.
30. The process according to claim 25, wherein the copper compound is selected from cuprous bromide, cupric bromide, cuprous iodide, cuprous chloride, cupric chloride, basic copper II carbonate, cuprous nitrate, cupric

nitrate, cuprous sulphate, cupric sulphate, cuprous sulphite,cuprous oxide, cuprous cetate, cupric acetate, cupric trifluoromethylsulphonate, cupric hydroxide, copper I methylate, copper II methylate, and chlorocupric methylate wth formula ClCuOCHs.
31. The process according to any one of claims 26 to 31 , wherein the quantity of catalyst used, expressed as the ratio of the weight of the diazonium salt, is in the range 0.1 % to 20 molo %, preferably 1 % to 10%.
32. The process according to claim 1, wherein the quantity of sulphur-containing compound is such that the ratio between the number of moles of sulphur-containing compound and the number of moles of diazonium salt is in the range 1 to 1.5.

33. The process according to anyone of claims 1 to 32, wherein the coupling reaction is carried out in an aqueous medium the quantity of water present in the reaction medium represents 100% to 500% by weight of the aromatic amine.
34. The process according to any one of claims 1 to 33, wherein the coupling reaction is carried out in the presence of an organic solvent, preferably a saturated carboxylic acid, more preferably acetic acid.
35. The process according to anyone of claims 1 to 34, wherein the
disulphide type sulphur-containing compound is added to the diazonium salt
followed by the catalyst.
36. The process according to any one of claims 1 to 35, wherein in coupling
reaction between the diazonium salt preferably with formula (III) and the

sulphur-contining compound preferably with formula (IV) is carried out at a temperature in the range 0°C to 120°C, preferably in the range 80°C to 100°C.
37. The process according to anyone of claims 1 to 36, wherein at the end of the reaction, a compound is obtained that preferably has the following formula (VI):

in which formula (VI), R1 R4 ond Z have the meanings defined in claims 3 to 6, and 15 to 23.
The process according to claim 37, wherein the compound with formula (VI) is 4- chloro-4'-thiomethyl- diphenylether.
39. A process for preparing a biphenyl type aromatic thioether substantially as herein described and exemplified.


Documents:

in-pct-2001-00873-che abstract.pdf

in-pct-2001-00873-che claims duplicate.pdf

in-pct-2001-00873-che claims.pdf

in-pct-2001-00873-che correspondence others.pdf

in-pct-2001-00873-che correspondence po.pdf

in-pct-2001-00873-che description (complete) duplicate.pdf

in-pct-2001-00873-che description (complete).pdf

in-pct-2001-00873-che form-1.pdf

in-pct-2001-00873-che form-26.pdf

in-pct-2001-00873-che form-3.pdf

in-pct-2001-00873-che form-5.pdf

in-pct-2001-00873-che pct search report.pdf


Patent Number 200974
Indian Patent Application Number IN/PCT/2001/873/CHE
PG Journal Number 30/2009
Publication Date 24-Jul-2009
Grant Date
Date of Filing 21-Jun-2001
Name of Patentee RHODIA CHIMIE
Applicant Address 25 QUAI PANL DOUMER, F-92408 COURBEVOIE, CEDEX,
Inventors:
# Inventor's Name Inventor's Address
1 BIGOURAUX JEAN-CHRISTOPHE, LA RIVOIRE, F-42800 DARGOIRE
2 SCHLAMA, THIERRY 20 CHEMIN DE PARSONGE, F-69570 DARDILLY
PCT International Classification Number C07C31/14
PCT International Application Number PCT/FR99/03273
PCT International Filing date 1999-12-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 98/16372 1998-12-23 France