3-(1-(tert-Butoxy)-2-methyl-1-oxopropan-2-yl)-5-methyl-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidine-6-carboxylic acid

3-(1-(tert-Butoxy)-2-methyl-1-oxopropan-2-yl)-5-methyl-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidine-6-carboxylic acid