Electrochemical coupling of two phenols which differ in their oxidation potential

Patent metadata

Field	Value
Publication number	US-2016010225-A1
Application number	US-201314772874-A
Country	US
Kind code	A1
Filing date	Dec 10, 2013
Priority date	Mar 7, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

Electrochemical process for coupling two phenols of different oxidation potential, and novel biphenols which can be prepared by this electrochemical coupling.

First claim

1 . Compound of one of the general formulae (I) to (III):

where R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 10 , R 11 , R 12 , R 13 , R 14 , R 16 , R 18 , R 19 , R 20 , R 21 , R 24 are selected from: —H, -alkyl, —O-alkyl;
R 8 , R 15 , R 17 are -alkyl;
R 1 , R 9 , R 22 , R 23 are selected from: —H, -alkyl;
and, if R 3 is -Me, R 1 and R 2 are not both —H.

2 . Compound according to claim 1 ,
where R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 10 , R 11 , R 12 , R 13 , R 14 , R 16 , R 18 , R 19 , R 20 , R 21 , R 24 are selected from: —H, -alkyl.

3 . Compound according to claim 1 ,
where R 4 and R 5 are —H.

4 . Compound according to claim 1 ,
where R 3 and R 6 are -alkyl.

5 . Compound according to claim 1 ,
where R 11 is —O-alkyl.

6 . Compound according to claim 1 ,
where R 13 is -alkyl.

7 . Compound according to claim 1 ,
where R 19 is -alkyl.

8 . Electrochemical process for preparing biphenols, comprising the process steps of:
a) introducing a solvent or solvent mixture and a conductive salt into a reaction vessel, b) adding a first phenol having an oxidation potential IE Ox 1I to the reaction vessel, c) adding a second phenol having an oxidation potential IE Ox 2I to the reaction vessel, where: IE Ox 2I>IE Ox 1I and IE Ox 2I−IE Ox 1I=IΔEI, the second phenol being added in excess relative to the first phenol, and the solvent or solvent mixture being selected such that IΔEI is in the range from 10 mV to 450 mV, d) introducing two electrodes into the reaction solution, e) applying a voltage to the electrodes, f) coupling the first phenol to the second phenol to give a biphenol.

9 . Process according to claim 8 ,
wherein the second phenol is used at least in twice the amount relative to the first phenol.

10 . Process according to claim 8 ,
wherein the ratio of first phenol to the second phenol is in the range from 1:2 to 1:4.

11 . Process according to claim 8 ,
wherein either the first phenol the second phenol has an —O-alkyl group.

12 . Process according to claim 8 ,
wherein the solvent or solvent mixture is selected such that IΔEI is in the range from 20 mV to 400 mV.

13 . Process according to claim 8 ,
wherein the reaction solution is free of organic oxidizing agents.

14 . Process according to claim 8 ,
wherein the first phenol and the second phenol are selected from: Ia, Ib, IIa, IIb, IIIa, IIIb:

where R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 10 , R 11 , R 12 , R 13 , R 14 , R 16 , R 18 , R 19 , R 20 , R 21 , R 24 are selected from: —H, -alkyl, —O-alkyl;
R 8 , R 15 , R 17 are -alkyl;
R 1 , R 9 , R 22 , R 23 are selected from: —H, -alkyl,
and the following combinations are possible here:

first phenol
Ia
Ib
IIa
IIb
IIIa
IIIb

second phenol
Ib
Ia
IIb
IIa
IIIb
IIIa

15 . Process according to claim 14 ,
where, if R 3 is -Me, R 1 and R 2 are not both —H.

Assignees

• Elsler Bernd
• Dyballa Katrin Marie
• Fridag Dirk
• Waldvogel Siegfried R
• Franke Robert
• Evonik Degussa Gmbh

Inventors

• Dyballa Katrin Marie
• Franke Robert
• Fridag Dirk
• Waldvogel Siegfried R
• Elsler Bernd

Classifications

• C25B3/10 Primary

  Chemistry & Metallurgy · mapped topic

• C07C43/23 Primary

  containing hydroxy or O-metal groups · CPC title

• C25B15/02

  Process control or regulation · CPC title

• C25B3/29 Primary

  Coupling reactions · CPC title

• C25B9/19

  with diaphragms · CPC title