1H-indene-1,3(2H)-dione, 2-[2-(4-methoxyphenyl)-2-oxoethyl]-2-methyl- 2-[2-(4-methoxyphenyl)-2-oxoethyl]-2-methyl-1H-indene-1,3(2H)-dione InChI=1/C19H16O4/c1-19(11-16(20)12-7-9-13(23-2)10-8-12)17(21)14-5-3-4-6-15(14)18(19)22/h3-10H,11H2,1-2H