Alkylation of 2-hydroxy-1-naphthaldehyde (I) with ethyl 4-bromobutyrate (II) in the presence of K2CO3 and tris[2-(2-methoxyethoxy)ethyl]amine furnished the naph-thoxybutyrate ester (III), which was hydrolyzed to the corresponding carboxylic acid (IV) using NaOH in aqueous dioxan. Condensation of (IV) with N-methyl rhodanine (V) by means of NaOAc in refluxing AcOH gave rise to the title compound.