2-butenedioic acid, dimethyl ester 624-48-6 CIS-BUTENEDIOIC ACID,DIMETHYL ESTER MALEIC ACID,DIMETHYLESTER InChI=1/C6H8O4/c1-9-5(7)3-4-6(8)10-2/h3-4H,1-2H dimethyl but-2-enedioate