Patent ID: 7601435

Claim:
A quinoxaline derivative represented by a formula (1): wherein in the formula, R 1 -R 12 each independently represents a hydrogen atom, a halogen atom, a lower alkyl group, an alkoxy group, an acyl group, a nitro group, a cyano group, an amino group, a dialkylamino group, a diarylamino group, a vinyl group, an aryl group, or a heterocyclic residue group; R 9 and R 10 , R 10 and R 11 , and R 11 and R 12 are each independent or mutually bonded to form an aromatic ring; Ar 1 -Ar 4 each independently represents an aryl group or a heterocyclic residue group; Ar 1 , Ar 2 , Ar 3 and Ar 4 are each independent or Ar 1 and Ar 2 , and Ar 3 and Ar 4 are respectively mutually bonded directly, or Ar 1 and Ar 2 , and Ar 3 and Ar 4 are bonded via oxygen (O), sulfur (S) or a carbonyl group, and at least one of R 1 - R 4 are different from the others of R 1 -R 4 .