Patent ID: 7183422

Claim:
A compound represented by the following formula wherein R 1 and R 2 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms; R 3 , R 4 , R 6 , and R 7 each independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; R 5 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, a substituted or unsubstituted acylamino group having 2 to 10 carbon atoms, or a substituted or unsubstituted heterocyclic group having 1 to 6 carbon atoms; R 8 represents a hydrogen atom or a substituted or unsubstituted acyl group having 2 to 10 carbon atoms; and R 9 , R 10 , R 11 , R 12 , and R 13 each independently represent a hydrogen atom or a substituent; provided that R 1 and R 2 may be bonded to each other to form a ring.