Ethyl Acetate → (7-Chloro-imidazo[1,2-c]pyrimidin-2-yl)-carbamic acid ethyl ester

Participants

Reaction Steps

A solution of 4-(2-hydroxyethyl)morpholine (2.77 g, 21.1 mmol) in dry tetrahydrofuran (5 mL) was added to a refluxing suspension of sodium hydride (557 mg, 23.2 mmol) in tetrahydrofuran (50 mL). This mixture was heated at reflux temperature for 3 h., then 2,5-dibromopyridine (1; 5.00 g, 21.1 mmol) added as a solid (portion wise). The resulting mixture was then heated at reflux for 15 h. After allowing the reaction mixture to cool, it was diluted with ethyl acetate (200 mL), then washed with water (200 mL). The water fraction was back-extracted with ethyl acetate (100 mL). The combined ethyl acetate fractions were washed with water (2×200 mL), then brine (100 mL) and dried over sodium sulfate. The drying agent was removed by filtration and the resultant liquor was concentrated under reduced pressure. The resulting yellow oil was purified by chromatography on silica gel (100% dichloromethane gradient to 10% methanol/dichloromethane). Compound 2 was isolated as a yellow oil (yield: 5.06 g, 84%);

Provenance & Evidence