Patent ID: 7259265

Claim:
A 4-substituted coumarin compound having a formula of wherein R is a phenyl being substituted with —CHO or a naphthyl, with R 1 , R 2 , R 3 , and R 4 being H, an alkyl having C 1-10 , X, NO 2 , CN, OCH 3 , COOCH 3 or OR 5 , R 5 being H or an alkyl having C 1-10 , and X being a halogen; and wherein R is an aryl, the coumarin compound is not in which R 5 is H, OH, OCH 3 , an alkyl having C 1-10 , or a halogen; R 6 is H, CH 3 , CH 3 O or a halogen; R 7 is CH 3 O or OH; R 8 is CH 3 O or OH; R 9 is H, CH 3 , OH or —OCH 2 O—.