60% sodium hydride in oil (0.24 g) was added to a solution of 5-(4-hydroxybenzylidene)-2,4-thiazolidinedione (0.664 g) in N,N-dimethylformamide (20 ml), and the mixture was stirred for 30 minutes. A solution of 4-chloromethyl-5-methyl-2-phenyloxazole (0.623 g) in N,N-dimethylformamide (10 ml) was added dropwise to the mixture under ice-cooling. After stirring at room temperature for 5 hours, the reaction solution was poured into water. The aqueous mixture was made acid with acetic acid and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and concentrated. The residue was chromatographed on a column of silica gel (50 g). From the fractions eluted with ethyl acetatehexane (1:2, V/V), there was obtained 5-[4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzylidene]-2,4-thiazolidinedione (0.49 g, 40.8%). Recrystallization from chloroform-methanol afforded colorless prisms, m.p. 225°-226° C. Elemental analysis for C21H16N2O4S, Calcd.: C, 64.27; H, 4.11; N, 7.14. Found: C, 64.49; H, 3.96; H, 6.86.
