title: Dibutyl 2,2'-bipyridine-4,4'-dicarboxyl-ate.
abstract: In the title compound, C(20)H(24)N(2)O(4), the mol-ecule lies on a centre of symmetry and is approximately planar (r.m.s. deviation= 0.013 Å for 26 non-H atoms). The carboxyl-ate group is inclined slightly to the neighbouring pyridine ring, forming a dihedral angle of 4.37 (2)°. The mol-ecules form stacks with an inter-planar separation of 3.547 (1) Å.
authors.forename: Qianli
authors.initials: Q
authors.lastname: Li
authors.forename: Rufen
authors.initials: R
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Shi