title: Ethyl 2-(3-chloro-2-pyridyl)-5-oxopyrazolidine-3-carboxylate.
abstract: In the mol-ecule of the title compound, C(11)H(12)ClN(3)O(3), the five membered ring adopts an envelope conformation. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Tan
authors.forename: Hai-Bing
authors.initials: HB
authors.lastname: He
authors.forename: Ming
authors.initials: M
authors.lastname: Xia
authors.forename: Xiang-Ning
authors.initials: XN
authors.lastname: Zhang
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Zhu