4-(3-Fluoro-anilino)thieno[2,3-b]pyridine-6-carb-oxy-lic acid.

In the title compound, C(14)H(9)FN(2)O(2)S, the thieno[2,3-b]pyridine residue is almost planar (r.m.s. deviation = 0.0194 Å), with the carb-oxy-lic acid group [dihedral angle = 11.9 (3)°] and the benzene ring [71.1 (4)°] being twisted out of this plane to different extents. An intra-molecular N-H⋯O(carbon-yl) hydrogen bond closes an S(6) ring. Supra-molecular chains along [01-1] mediated by O-H⋯N(pyridine) hydrogen bonds feature in the crystal. A three-dimensional architecture is completed by π-π inter-actions occurring between the benzene ring and the two rings of the thieno[2,3-b]pyridine residue [centroid-centroid distances = 3.6963 (13) and 3.3812 (13) Å]. The F atom is disordered over the two meta sites in a near statistical ratio [0.545 (5):0.455 (5)].