title: 5-(Methoxy-carbon-yl)thio-phene-2-carboxylic acid.
abstract: In the title compound, C(7)H(6)O(4)S, a monoester derivative of 2,5-thio-phene-dicarboxylic acid, the carboxylic acid and the carboxylic acid ester groups are approximately coplanar with thio-phene ring, making a dihedral angle of 3.1 (4) and 3.6 (4)°, respectively. In the crystal structure, mol-ecules are connected by classical inter-molecular O-H⋯O hydrogen bonds, forming centrosymmetric dimers.
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Xia
authors.forename: Mu-Wei
authors.initials: MW
authors.lastname: Ji
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Guo-Xin
authors.initials: GX
authors.lastname: Sun
authors.forename: Wen-Fang
authors.initials: WF
authors.lastname: Xu