Pyridine → HCID 19871309, compound

Participants

Reaction Steps

A solution of carbonyl diimidazole (8.00 g) and 2-{[4-(2,3-dichlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-1,4-dihydropyrid-2-yl]methoxy}acetic acid (20.00 g) (see European patent application publication No. 0100189) in dichloromethane (400 ml) was stirred at room temperature under nitrogen for 2 hours and then added to a solution of pyridine (3.60 g) and 2,2-dimethyl-1,3-dioxan-4,6-dione (6.50 g) in dichloromethane over 5 minutes. The mixture was stirred at room temperature for 2 days, washed successively with ice-cooled 2.5M hydrochloric acid and saturated brine, dried over magnesium sulphate and evaporated. The residue was dissolved in water (300 ml) and acetic acid (150 ml) and refluxed for 5 hours. The mixture was evaporated and partitioned between diethyl ether (800 ml) and 10% aqueous sodium carbonate. The ether solution was dried over magnesium sulphate and evaporated. The residue was chromatographed on silica (50 g) using 30% hexane in dichloromethane as the eluant. Fractions which contained the pure product were evaporated to give the title compound (6.5 g), m.p. 117°-119°.

Provenance & Evidence