Dimethyl Sulfoxide → HCID 178448420, compound

Participants

Reaction Conditions

Reaction Steps

To a mixture of sodium 5-oxo-5,6-dihydro-2H-pyran-3-olate (Li, Wenke; Wayne, Gregory S.; Lallaman, John E.; Wittenberger, Steven J. J. Org. Chem. (2006), 71, 1725-1727) (1.36 g, 10 mmol) and n-butylthiourea (Trans World) (1.32 g, 10 mmol) in tetrahydrofuran (15 mL) was added a mixture of DMSO/12 N HCl (1/1 molar ratio, 4.6 mL, 30 mmol). The reaction mixture was heated at 40° C. for overnight, and then cooled. The mixture was diluted with ethyl acetate and washed with aqueous sodium bicarbonate. The organic extract was dried (MgSO4), filtered and concentrated. The residue was dried under vacuum for 12 h and dissolved in tetrahydrofuran (40 mL). To the solution was added 5-chloro-2-methoxy-benzoic acid (1.86 g, 10.0 mmol), N-(3-dimethylaminopropyl)-N-ethylcarbodimide hydrochloride (1.91 g, 10.0 mmol), 1-hydroxybenzotriazole (1.35 g, 10.0 mmol) and triethylamine (3.5 mL, 3.5 mmol). The mixture was stirred overnight at 80° C. and then cooled at room temperature. The mixture was diluted with ethyl acetate, washed with 1 M aqueous NaHCO3, dried (Na2SO4), filtered and concentrated. The residue was purified by flash chromatography (SiO2, 0-75% ethyl acetate in hexanes) to afford 412 mg of the title compound. MS (ESI+) m/z 395 (M+H)+

Provenance & Evidence