2-Pyridinecarboxaldehyde → 2-(5-{1-[4-(ethylsulfonyl)phenyl]-2-(tetrahydro-2H-pyran-4-yl)ethyl}-1H-pyrrol-2-yl)pyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-[4-(ethylsulfonyl)phenyl]-5-(tetrahydro-2H-pyran-4-yl)pent-1-en-3-one (0.409 g) in ethanol (15 mL) were added pyridine-2-carbaldehyde (0.139 mL), 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazol-3-ium chloride (36 mg) and triethylamine (0.073 mL), and the mixture was heated under reflux for 1 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under m reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=30:70-80:20, volume ratio) to give a colorless oil. To a solution of the obtained oil in acetic acid (10 mL) was added ammonium acetate (356 mg), and the mixture was stirred at 110° C. for 3 hr. The reaction mixture was neutralized with saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The extract was washed successively with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=10:90-80:20, volume ratio) to give the title compound (0.350 g, yield 69%) as a colorless amorphous solid. MS: 425 (MH+).

Provenance & Evidence