Ethyl 2-[(2-hy­droxy­benzyl­idene)amino]-6-methyl-4,5,6,7-tetra­hydro­thieno[2,3-c]pyridine-3-carboxyl­ate

The title compound, C(18)H(20)N(2)O(3)S, exists as the phenol–imine form in the crystal and there are bifurcated intra­molecular O—H⋯(N/O) hydrogen bonds present. The conformation about the C=N bond is anti (1E); the C=N imine bond length is 1.287 (4) Å and the C=N—C angle is 122.5 (3)°. In the tetrahydrothienopyridine moiety, the six-membered ring has a flattened-boat conformation. In the crystal, mol­ecules are stacked nearly parallel to (110) and a weak C—H⋯π inter­action is observed. The carbonyl O atom is disordered over two positions and was refined with a fixed occupancy ratio of 0.7:0.3.