9-((1,3-dioxolan-2-yl)methyl)-1,3-dimethyl-3,9-dihydro-1H-purine-2,6-dione; Doxoflylline Impurity-1 ;9-(1,3-Dioxolan-2-ylmethyl)-3,9-dihydro-1,3-dimethyl-1H-purine-2,6-dione