US 7,449,588 B2
Methods of stabilizing thiophene derivatives
Friedrich Jonas, Aachen (Germany); Klaus Wussow, Netphen (Germany); and Knud Reuter, Krefeld (Germany)
Assigned to H.C. Starck GmbH, Goslar (Germany)
Filed on May 04, 2007, as Appl. No. 11/744,264.
Claims priority of application No. 10 2006 020 744 (DE), filed on May 04, 2006.
Prior Publication US 2007/0260070 A1, Nov. 08, 2007
Int. Cl. C07D 333/16 (2006.01); C07D 495/06 (2006.01)
U.S. Cl. 549—50  [549/78] 20 Claims
 
1. A method of stabilizing thiophene derivatives comprising:
(a) providing a thiophene derivative of the general formula (I):

OG Complex Work Unit Drawing
wherein R1 and R2 each independently represents a moiety selected from the group consisting of hydrogen, optionally substituted C1-20 alkyl groups which can contain up to 5 heteroatoms selected from the group consisting of oxygen and sulfur, optionally substituted C1-20 oxyalkyl groups which can contain up to 5 heteroatoms selected from the group consisting of oxygen and sulfur, or wherein R1 and R2 together represent a fused cyclic moiety selected from the group consisting of optionally substituted C1-20 dioxyalkylene groups and C1-20 dioxyarylene groups; and
(b) treating the thiophene derivative with a basic compound.