Ethanol → 2-(5-{1-[4-(cyclopropylsulfonyl)phenyl]-2-(tetrahydro-2H-pyran-4-yl)ethyl}-1H-pyrrol-2-yl)-5-(2-methylprop-1-en-1-yl)pyridine

Participants

Reaction Conditions

Reaction Steps

A solution of 4-[4-(cyclopropylsulfonyl)phenyl]-5-(tetrahydro-2H-pyran-4-yl)pent-1-en-3-one (1.20 g) in a mixed solvent of tetrahydrofuran (15 mL) and ethanol (15 mL) was deaerated, 5-(2-methylprop-1-en-1-yl)pyridine-2-carbaldehyde (0.666 g), 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazol-3-ium chloride (93 mg) and triethylamine (0.192 mL) were added, and the mixture was stirred at 70° C. for 1.5 hr under a nitrogen atmosphere. 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 magnesium sulfate and concentrated under reduced pressure. To a solution of the residue in acetic acid (50 mL) was added ammonium acetate (2.65 g), and the mixture was stirred at 110° C. for 2 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 sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=10:90-60:40, volume ratio) and recrystallized from hexane-ethyl acetate to give the title compound (1.35 g, yield 80%) as colorless crystals. MS: 491 (MH+). melting point 114-116° C.

Provenance & Evidence