2-(3-Methyl-sulfanyl-5-propyl-1-benzofuran-2-yl)acetic acid.

The title compound, C(14)H(16)O(3)S, was prepared by alkaline hydrolysis of ethyl 2-(3-methyl-sulfanyl-5-propyl-1-benzofuran-2-yl)acetate. In the crystal structure, the carboxyl groups are involved in inter-molecular O-H⋯O hydrogen bonds, which link the mol-ecules into centrosymmetric dimers. These dimers are further packed into stacks along the a axis by weak C-H⋯π inter-actions.