(2Z)-2-bromobut-2-enedioic acid 2-butenedioic acid, 2-bromo-, (2Z)- 644-80-4 InChI=1/C4H3BrO4/c5-2(4(8)9)1-3(6)7/h1H,(H,6,7)(H,8,9)/b2-1