Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 527-17-3, Whether you call it Duroquinone, 2 -3 -5 -6-Tetramethyl-1 -4-benzoquinone or Tetramethyl-p-benzoquinone you can be assured the Duroquinone products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.