Patent ID: 7994345

Claim:
A process for purifying a thiophene represented by general formula (I), wherein, R 1 and R 2 are each selected independently from the group consisting of hydrogen, linear or branched C 1 -C 20 -alkyl groups, linear or branched C 1 -C 20 -oxyalkyl groups, linear or branched C 1 -C 20 -alkyl groups which are interrupted by 1 to 5 oxygen atoms, linear or branched C 1 -C 20 -oxyalkyl groups which are interrupted by 1 to 5 sulphur atoms, a fused ring of linear or branched C 1 -C 20 -dioxyalkylene formed by R 1 and R 2 together, and a fused ring of linear or branched C 1 -C 20 -dioxyarylene formed by R 1 and R 2 together, and said thiophene being liquid at room temperature, said method being selected from the group consisting of, a method (I) comprising, (a) providing a first solution comprising said thiophene and at least one solvent, and (b) cooling said first solution to a temperature below the melting temperature of said thiophene, thereby precipitating said thiophene as a solid from said first solution, and a method (II) comprising, (a) providing a second solution comprising at least one solvent and optionally said thiophene, (b) cooling said second solution to a temperature below the melting temperature of said thiophene, to form a cooled second solution, and (c) adding said thiophene to said cooled second solution, thereby precipitating said thiophene as a solid from said cooled second solution.