To a solution of 4-[4-(cyclopropylsulfonyl)phenyl]-5-(tetrahydro-2H-pyran-4-yl)pent-1-en-3-one (300 mg) in ethanol (5 mL) were added pyridine-2-carbaldehyde (100 μL), 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazol-3-ium chloride (25 mg) and triethylamine (52 μL), and the mixture was stirred with heating under reflux for 2 hr. After cooling to room temperature, the reaction mixture was diluted with ethyl acetate and washed with water. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and the title compound (220 mg, yield 56%) was obtained as a brown oil from a fraction eluted with ethyl acetate-hexane (4:1, volume ratio). MS: 456 (MH+).
