Patent ID: 7442448

Claim:
A compound represented by the following formula (1): wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 each independently are hydrogen, a straight or branched alkyl group haying 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a halogen group, a substituted or un-substituted aromatic group having 5 to 18 carbon atoms, a cycloalkyl group having 5 to 18 carbon atoms, or an aromatic heterocyclic group of 5 to 18 carbon. atoms containing one or more hetero-atoms selected from the group consisting of N, O and S; A 1 is a straight or branched alkyl group having 1 to 18 carbon atoms; A 2 is —COA 4 ; A 3 is a straight or branched alkyl group having 1 to 18 carbon atoms; or A 2 and A 3 form together a cycloalkanone having 5 to 18 carbon atoms; A 4 is a straight or branched alkyl group having 1 to 18 carbon atoms; is a single bond or double bond; and Py is a substituted or un-substituted pyridine or isoquinoline.