The 1,4- and 2,3-dimethyl esters of benzene-1,2,3,4-tetracarboxylic acid, a degradation product of viridin, have been prepared and the 1,4-diester has been subjected to Hunsdiecker decarboxylation. The structure of the product, methyl 2,3-dibromoterephthalate, has been established by synthesis of the isomeric dibromoterephthalic esters.