CAS 21004-11-5 appears in our catalog under these names: 2,5–Dimethoxyterephthalicacid, 2,5-Dimethoxy-1,4-benzenedicarboxylic acid 98%, 2,5-Dimethoxy-1,4-benzenedicarboxylic acid, 98%, 98%. Offered by: GLPBio, Ambeed, Chemat. Available pack sizes: 500mg, 100mg, 250mg, 1g, 5g.