Organic compounds -- part of the class 532-570 series – Organic compounds – Sulfonic acids or salts thereof
Reexamination Certificate
1998-09-22
2001-02-27
O'Sullivan, Peter (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Sulfonic acids or salts thereof
C562S084000, C562S087000, C564S291000, C564S292000, C564S296000, C568S643000, C568S812000, C568S813000, C570S128000, C570S142000, C585S435000, C585S440000, C585S442000
Reexamination Certificate
active
06194606
ABSTRACT:
The present invention relates to new compounds which are useful as intermediates for the production of fluorescent whitening agents and to a process for their production.
In U.S. Pat. No. 2,465,486, a process is described for the production of 4,4′-divinyl-biphenyl. This process comprises dehydrating 4,4′-di-(&agr;-hydroxyethyl)-biphenyl in the presence of a dehydrating agent. The reaction is preferably conducted in an atmosphere of inert gas, at reduced pressure and at elevated temperature. The gaseous 4,4′-divinyl-biphenyl so obtained is chilled to convert it to the solid state.
A further known process for the production of 4,4′-divinyl-biphenyl is that described in JP 08003079. In this process, 4,4′-diethyl-biphenyl is contacted with a dehydrogenation catalyst in the presence of steam; a cooling medium is rapidly added to the gaseous reaction product containing 4,4′-divinyl-biphenyl; and a solution or dispersion containing the 4,4′-divinyl-biphenyl is formed.
The compound 4,4′-divinyl-biphenyl is known for use as a starting material for the production of copolymers with other monomers such as styrene. It is also possible to use 4,4′-divinyl-biphenyl as a starting material for certain fluorescent whitening agents. Thus, 4,4′-divinyl-biphenyl may be reacted, in the presence of a palladium compound, according to the Heck reaction, with diazo compounds to form distyryl-diaryl fluorescent whitening agents. If so used in the Heck reaction, however, there would be obtained only the corresponding symmetrical distyryl-diaryl fluorescent whitening agents.
The present invention provides, as a first aspect, a new class of vinyl-biphenyl compounds which are useful for the production of asymmetrical or symmetrical distyryl-diaryl fluorescent whitening agents.
Accordingly, the present invention provides compounds having the formula:
in which R is hydrogen or C
1
-C
4
alkyl, preferably hydrogen, and Y is hydrogen, C
1
-C
4
alkyl, C
1
-C
4
alkoxy, CF
3
, halogen (F, Cl, Br or I) or SO
3
M in which M is hydrogen, Na, K, Ca, Mg, ammonium, mono-, di-, tri- or tetra-C
1
-C
4
alkylammonium, mono-, di- or tri-hydroxyalkylammonium or ammonium that is di- or tri-substituted with a mixture of C
1
-C
4
alkyl and C
1
-C
4
hydroxyalkyl groups. Preferably Y is hydrogen.
The preferred compound of formula (1) is 4-vinyl-4′-&agr;-hydroxyethyl-biphenyl.
The present invention also provides a process for the production of a compound of formula (1), comprising partially dehydrating a compound having the formula (2):
in which R and Y have their previous significance, at a temperature in the range of from 140° to 260° C., preferably in the range of from 180° to 220° C., in a high-boiling inert solvent.
The solvent used is preferably a polyalkylene glycol or a di-alkyl ether thereof, preferably a polyethylene glycol or a dimethyl ether thereof, especially diethylene glycol or triethylene glycol-dimethyl ether. If an acid-free solvent such as triethylene glycol-dimethyl ether is used, then a minor amount of an acidic compound such as p-toluene sulfonic acid is preferably present during the partial dehydation process according to the invention.
The partial dehydation process according to the second aspect of the invention is preferably conducted at normal pressure and in the presence of a effective amount of a compound which is an inhibitor of the polymerisation of styrene monomers. Examples of such polymerisation inhibitors include quinones, hindered phenols and amines. The preferred polymerisation inhibitor is tert.-butylpyrocatechol.
At dehydration temperatures above 200° C., the product of formula (1) begins to dehydrate to form 4,4′-divinyl-biphenyl. Accordingly, the reaction temperature used in the partial dehydation process according to the invention is preferably held in the range of from 180° to 220° C. and the content of the reaction mixture is monitored, and the reaction is stopped as soon as the optimal amount of the product of formula (2) is detected in the reaction mixture.
In addition to the partial dehydration process according to the present invention for the production of a compound of formula (1), other possible routes are available for obtaining a compound of formula (1). The various routes are summarised in the following scheme:
As a third aspect of the present invention, there is provided a process for the production of a compound having the formula:
in which R and Y have their previous significance, comprising dehydrating a compound having the formula (1), at a temperature in the range of from 140° to 260° C., preferably in the range of from 180° to 220° C., in a high-boiling inert solvent.
The solvent used is preferably a polyalkylene glycol or an di-alkyl ether thereof, preferably a polyethylene glycol or a dimethyl ether thereof, especially diethylene glycol or triethylene glycol-dimethyl ether. If an acid-free solvent such as triethylene glycol-dimethyl ether is used, then a minor amount of an acidic compound such as p-toluene sulfonic acid is preferably present during the partial dehydation process according to the invention.
The dehydation process according to the third aspect of the present invention is preferably conducted at normal pressure and in the presence of a effective amount of a compound which is an inhibitor of the polymerisation of styrene monomers. Examples of such polymerisation inhibitors include quinones, hindered phenols and amines. The preferred polymerisation inhibitor is tert.-butylpyrocatechol.
The preferred starting material of formula (2) is 4-vinyl-4′-&agr;-hydroxyethyl-biphenyl which is dehydrated according to the process of the third aspect of the present invention to produce 4,4′-divinyl-biphenyl.
A fourth aspect of the present invention comprises a process for the production of asymmetric or symmetric compounds having the formula:
in which Y has its previous significance and R
1
and R
2
are the same or different and each is a phenyl group, optionally substituted with one or more groups of formula SO
3
M in which M has its previous significance, which process comprises:
a) reacting a compound having the formula (1), in the presence of a palladium compound, with a diazonium compound having the formula R
1
—N
2
X
&thgr;
in which X
&thgr;
is an anion, to produce a compound having the formula;
in which Y, R and R
1
have their previous significance;
b) dehydrating the compound having the formula (5), at a temperature in the range of from 140° to 260° C., preferably in the range of from 180° to 220° C., in a high-boiling inert solvent to produce a compound having the formula;
in which Y, R and R
1
have their previous significance; and
c) reacting a compound having the formula (6), under the conditions of the Heck reaction, with a diazonium compound having the formula R
2
—N
2
X
&thgr;
in which R
2
and X
&thgr;
have their previous significance, to produce a compound having the formula (4).
Step b) of the process, the dehydration of the compound of formula (5) to the compound of formula (6), is conveniently conducted according to the dehydration procedure described in relation to the process for the production of a compound of formula (3), comprising dehydrating a compound having the formula(1).
The reaction of a compound having the formula (1) with a diazonium compound having the formula R
1
—N
2
X
&thgr;
, and the reaction of a compound having the formula (6) with a diazonium compound having the formula R
2
—N
2
X
&thgr;
, viz. steps a) and c) of the process, are each conducted under the conditions of the Heck reaction, namely in the presence of a palladium compound, as catalyst. The reaction is conducted in an organic solvent such as water, an aliphatic alcohol or an aliphatic acid.
Examples of palladium compound catalysts include inorganic palladium salts such as the chloride, bromide, iodide, nitrate, sulfate, acetate or propionate, and mixtures thereof. The palladium compound may also be used in the form of a complex. Examples of suitable complex formers include
Casagrande Bruno
Eliu Victor
Siebenhaar Bernd
Ciba Specialty Chemicals Corporation
Mansfield Kevin T.
O'Sullivan Peter
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