KOH (0.089 g, 1.59 mmol) was added to a solution of dicyclopropyl(5-mercapto-1,3,4-thiadiazol-2-yl)methanol (0.363 g, 1.60 mmol) in dry MeOH. When a solution was obtained, the reaction mixture was concentrated to dryness. Dry toluene was then added and the mixture was concentrated to dryness again. The residue was dissolved in NMP, 7-bromo-4-pyridin-3-yl-2H-chromen-2-one (400 mg, 1.32 mmol) was added and the resulting mixture was stirred at 120° C. for 16 h. The reaction mixture was cooled and partitioned between aqueous NH4OAc and EtOAc. The organic phase was washed with brine, dried over anhydrous Na2SO4, concentrated and purified on silica gel column (toluene-acetone, 90:10 to 70:30) to give the title compound. 1H NMR (400 MHz, CDCl3): δ 8.82 (d, 1H), 8.72 (s,1H), 7.81 (dt, 1H), 7.64 (s, 1H), 7.58-7.50 (m, 1H), 7.48-7.41 (m, 2H), 6.46 (s, 1H), 2.57 (s, 1H), 1.40-1.31 (m, 2H), 0.69-0.57 (m, 6H), 0.50-0.44 (m, 1H).
