Coupling of two arenes with selenium dioxide to give a selenobiaryl ether
The present invention relates to a method for coupling two arenes with selenium dioxide to give a selenobiaryl ether. The method of the present invention includes: adding a first arene to the reaction mixture, adding a second arene to the reaction mixture, adding selenium dioxide to the reaction mixture, adding an acid having a pKa in the range from 0 to 5 to the reaction mixture, and adjusting the reaction temperature of the reaction mixture such that the first arene and the second arene are converted to a selenobiaryl ether. The present invention also relates to novel selenobiaryl ethers.
1. A method for preparing selenobiaryl ethers comprising:
I) forming a reaction mixture by:
a) adding a first arene to the reaction mixture,
b) adding a second arene to the reaction mixture,
c) adding selenium dioxide to the reaction mixture,
d) adding an acid having a pKa in the range from 0 to 5 to the reaction mixture,
II) adjusting the reaction temperature of the reaction mixture to a temperature in the range from 20° C. to 100° C. such that the first arene and the second arene are converted to the selenobiaryl ether,
wherein the second arene does not include phenols, and
wherein the wherein the first arene in method step a) is a compound of the general formula I:
wherein R 1 , R 2 , R 3 , R 4 , R 5 are each independently selected from:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —(C 6 -C 20 )-aryl, —O—(C 6 -C 20 )-aryl, -halogen, —OC═O—(C 1 -C 12 )-alkyl,
two adjacent radicals may additionally be joined to one another to form a condensed system,
where the alkyl and aryl groups mentioned may be substituted,
and at least one of the R 1 , R 2 , R 3 , R 4 , R 5 radicals is —H.
2. The method according to claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 are each independently selected from:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —(C 6 -C 20 )-aryl, —O—(C 6 -C 20 )-aryl,
where the alkyl and aryl groups mentioned may be substituted,
and at least one of the R 1 , R 2 , R 3 , R 4 , R 5 radicals is —H.
3. The method according to claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , are each independently selected from:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl,
where the alkyl groups mentioned may be substituted,
and at least one of the R 1 , R 2 , R 3 , R 4 , R 5 radicals is —H.
4. The method according to claim 1 , wherein the second arene in method step b) is a compound of the general formula II:
wherein R 6 , R 7 , R 8 , R 9 , R 10 are each independently selected from:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —(C 6 -C 20 )-aryl, —O—(C 6 -C 20 )-aryl, -halogen, —OC═O—(C 1 -C 12 )-alkyl,
two adjacent radicals may additionally be joined to one another to form a condensed system,
where the alkyl and aryl groups mentioned may be substituted,
and at least one of the R 6 , R 7 , R 8 , R 9 , R 10 radicals is —H.
5. The method according to claim 4 , wherein R 6 , R 7 , R 8 , R 9 , R 10 are each independently selected from:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —(C 6 -C 20 )-aryl, —O—(C 6 -C 20 )-aryl,
where the alkyl and aryl groups mentioned may be substituted,
and at least one of the R 6 , R 7 , R 8 , R 9 , R 10 radicals is —H.
6. The method according to claim 4 , wherein R 6 , R 7 , R 8 , R 9 , R 10 are each independently selected from:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl,
where the alkyl and aryl groups mentioned may be substituted,
and at least one of the R 6 , R 7 , R 8 , R 9 , R 10 radicals is —H.
7. The method according to claim 4 , wherein the first arene corresponds to the second arene.
8. The method according to claim 1 , wherein the selenium dioxide is added in method step c) in a molar ratio based on the sum total of the first and second arenes within a range from 0.25 to 1.5.
9. The method according to claim 1 , wherein the acid is acetic acid.
10. A compound of the formula 1 or 2:
11. The method according to claim 1 , wherein the added acid in step d) is present in amounts that forms a solution of dissolved first and second arenes and selenium dioxide.