Process for preparing a polyaromatic compound

Details Process for preparing a polyaromatic compound Process for preparing a polyaromatic compound

2002-05-15

2003-07-08

Seaman, D. Margaret (Department: 1625)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

C546S006000, C546S022000, C546S304000, C562S035000, C562S041000, C568S002000, C568S016000

Reexamination Certificate

active

06590100

ABSTRACT:

The present invention relates to a process for preparing a polyaromatic compound.
The invention relates in particular to a compound of the biphenyl type.
In the subsequent specification of the present invention, the term “polycyclic aromatic compound” denotes a compound comprising at least one sequence of two aromatic, carbocyclic and/or heterocyclic rings.
The term “aromatic compound” denotes the classical concept of aromaticity as defined in the literature, in particular by Jerry MARCH, Advanced Organic Chemistry, 4th edition, John Wiley and Sons, 1992, pp. 40 et seq.
More simply, the expression “aryl” will be used to denote all aromatic compounds, whether carbocyclic aromatic compounds or heterocyclic aromatic compounds.
Structures of the biaryl type are encountered in numerous molecules which are used in the agrochemical sector, especially in herbicides or pesticides, or in the pharmaceutical sector. In particular, a process is sought for preparing compounds of the alkylbiphenyl or cyanobiphenyl type.
Miyaura Norio [Tetrahedron Letters 37, (17), pp. 2993-6 (1996)] describes the preparation of compounds of the biphenyl type in accordance with the Suzuki reaction, which involves reacting an arylboronic acid and a chlotoaromatic compound in the presence of a nickel catalyst, NiCl
2
(dppf), potassium phosphate, and butyllithium in dioxane.
The said process makes it possible to employ a choloroaromatic compound, which is of greater interest from an economic standpoint than a reactant of bromoaromatic type; however, the process has the disadvantage of being conducted in an organic solvent.
The object of the present invention is to provide a process for preparing compounds of the biaryl type in an aqueous or aqueous-organic medium.
What has now been found, and constitutes the subject-matter of the present invention, is a process for preparing a polycyclic aromatic compound comprising at least one sequence of two aromatic rings, which consists in reacting an aromatic compound bearing a leaving group and an arylboronic acid and/or its derivatives in the presence of a base and an effective amount of a nickel catalyst, characterized in that the reaction is conducted in a reaction solvent which is water optionally in a mixture with an organic solvent and in the presence of an effective amount of a catalyst based on nickel with at least one water-soluble phosphine ligand.
In accordance with the process of the invention, it has been found that it is possible to carry out a coupling reaction of an arylboronic acid and a haloaromatic compound in the presence of water if use is made of a catalyst based on nickel with a water-soluble phosphine ligand.
It is important according to the invention that the phosphine is water-soluble.
A first embodiment of the invention consists in preparing a complex of the nickel with the water-soluble phosphine in situ, by employing separately in the reaction medium a nickel salt or a complex of nickel and a water-soluble phosphine.
Another variant embodiment of the process of the invention is to prepare this type of complex beforehand, at the time of use, and then to introduce it into the reaction medium.
One advantage of the process of the invention lies in the use of a catalyst based on nickel which is less expensive than the palladium catalysts most frequently used in the coupling reactions of an arylboronic acid and a haloaromatic compound. Furthermore, nickel is a metal which is easily introduced into the C(aromatic)—Cl bond.
More precisely, the aromatic compound bearing at least one leaving group, referred to hereinafter as “haloaromatic compound” corresponds to the general formula (I):
in which:
A symbolizes the radical of a ring which forms all or part of a carbocyclic or heterocyclic, aromatic, monocyclic or polycyclic system,
R, which is identical or different at each occurrence, represents substituents on the ring,
Y represents a leaving group, preferably a halogen atom or a sulphonic ester group of formula —OSO
2
—R, in which R is a hydrocarbon group, and
n represents the number of substituents in the ring.
In the formula of the sulphonic ester groups, R is a hydrocarbon group of arbitrary type. However, given that Y is a leaving group, it is of interest from an economic standpoint for R to be simple in nature, and to represent more particularly a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl or ethyl group, although it may also represent, for example, a phenyl or tolyl group or a trifluoromethyl group. Among the groups Y, the preferred group is a triflate group, which corresponds to a group R representing a trifluoromethyl group.
As preferred leaving groups it is preferred to select a bromine or chlorine atom.
The invention applies in particular to haloaromatic compounds corresponding to the formula (I) in which A is the radical of a cyclic compound having preferably at least 4 atoms in the ring, preferably 5 or 6, which is optionally substituted, and representing at least one of the following rings:
a monocyclic or polycyclic aromatic carbocycle,
a monocyclic or polycyclic aromatic heterocycle containing at least one of the heteroatoms O, N and S.
Without limiting the scope of the invention, it will be specified that the optionally substituted radical A represents the radical:
1.—of an aromatic, monocyclic or polycyclic carbocyclic compound.
The term “polycyclic carbocyclic compound” denotes:
a compound consisting of at least two aromatic carbocycles which jointly form ortho-condensed or ortho- and peri-condensed systems;
a compound consisting of at least two carbocycles only one of which is aromatic, which jointly form ortho-condensed or ortho- and peri-condensed systems.
2.—an aromatic, monocyclic or polycyclic heterocyclic compound.
The term “polycyclic heterocyclic compound” is defined as:
a compound consisting of at least two heterocycles containing at least one heteroatom in each ring, at least one of the two rings being aromatic, and jointly forming ortho-condensed or ortho- and peri-condensed systems;
a compound consisting of at least one carbocycle and at least one heterocycle, at least one of the rings being aromatic, and jointly forming ortho-condensed or ortho- and peri-condensed systems.
More particularly, the optionally substituted radical A represents one of the following rings:
an aromatic carbocycle:
an aromatic bicycle comprising two aromatic carbocycles:
a partially aromatic bicycle containing two carbocycles one of which is aromatic:
an aromatic heterocycle:
an aromatic bicycle comprising one aromatic carbocycle and one aromatic heterocycle:
a partially aromatic bicycle comprising one aromatic carbocycle and one heterocycle:
an aromatic bicycle comprising two aromatic heterocycles:
a partially aromatic bicycle comprising one carbocycle and one aromatic heterocycle:
a tricycle comprising at least one carbocycle or one aromatic heterocycle:
In the process of the invention, it is preferred to employ a haloaromatic compound of formula (I) in which A represents an aromatic nucleus, preferably a benzenic or naphthalenic nucleus.
The aromatic compound of formula (I) can bear one or two or more substituents.
The number of substituents present on the ring depends on the carbon condensation of the ring and on the presence or absence of unsaturations on the ring.
The maximum number of constituents which can be borne by a ring is readily determined by the person skilled in the art.
In the present text, the term “two or more” generally means less than 4 substituents on an aromatic nucleus.
Examples of substitutents are given hereinbelow, although this list is not limitative.
The identical or different group or groups R preferably represent one of the following groups:
a linear or branched alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl or tert-butyl,
a linear or branched alkenyl or alkynyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, such as vinyl or allyl,
a linear or br

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