2,3,5,6-tetramethylbenzo-1,4-quinone 2,5-cyclohexadiene-1,4-dione, 2,3,5,6-tetramethyl- 527-17-3 InChI=1/C10H12O2/c1-5-6(2)10(12)8(4)7(3)9(5)11/h1-4H duroquinone tetramethyl-p-benzoquinone