The title compound 2-(3-methyl-5-(methylthio)-4H-1,2,4-triazol-4-yl)isoindoline-1,3-dione(C12H10N4O2S, Mr = 274.30) has been synthesized by a three-step procedure including the cyclization, hydrazinolysis and substitution reactions, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 12.264(3), b = 14.646(3), c = 14.349(4) , β = 91.69(3)°, μ = 0.255 mm-1, Mr = 274.30, V = 2576.2(10) 3, Z = 8, Dc = 1.414 g/cm3, F(000) = 1136, R = 0.0487 and w R = 0.1329 for 4048 observed reflections with Ⅰ > 2σ(Ⅰ). In addition, the preliminary bioassay suggested that the title compound 6 exhibits relatively good antitumor activity against HT-29 and MCF-7.
