Patent ID: 8350065

Claim:
A method of preparing 5,6-dimethylxanthenone-4-acetic acid, comprising the steps of: wherein X represents H, or totally 0 to 4 substitutes at 5-8 position selected from R, OR, halogen, NO 2 , NR 2 , SR, SO 2 R, CF 3 , CN, CO 2 R, CONHR, or COR, wherein R represents a C 1-6 aliphatic group, C 3-6 saturated ring substitute, OH, methoxy, NH 2 , or N(methyl) 2 , and R 2 represents a lower alkyl, or a lower alkyl comprising OH, NH 2 , or OCH 3 ; Y represents a halogen selected from Cl, Br, or I; Y 1 represents a halogen selected from Cl, Br, or I; and Z represents H, or totally 0 to 3 substitutes at 1-3 position selected from R, OR, halogen, NO 2 , NR 2 , SR, SO 2 R, CF 3 , CN, CO 2 R, CONHR, or COR, wherein R represents a C 1-6 aliphatic group, C 3-6 saturated ring substitute, OH, methoxy, NH 2 , or N(methyl) 2 , and R 2 represents a lower alkyl, or a lower alkyl comprising OH, NH 2 , or OCH 3 .