Regioselective synthesis of novel 8-hydroxy-3-sulfanyl-7-undecyl-5H-[1,2,4]triazolo[3,4-b][1,3,4]benzothiadiazole-6,9-dione (3) by condensation of 2-bromo-3,6-dihydroxy-5-undecyl-1,4-benzoquinone (bromoembelin) (1) with 4-amino-4H-1,2,4-triazole-3,5-dithiol (2) in ethanol. Reaction of 3 with various alkyl, aralkyl and phenacyl halides gave the corresponding thioethers (4).