Trifluoroacetic acid → Ethyl 4-(2-oxo-1,4-dihydropyrido[3,4-d]pyrimidin-3(2H)-yl)piperidine-1-carboxylate

Beteiligte Stoffe

Reaktionsschritte

Trifluoroacetic acid (1.43 g) was added to a solution of the material from Step A (0.47 g, 1.24 mmol) in dichloromethane (10 mL). After stirring overnight, the reaction was concentrated. This material was dissolved in acetonitrile (5 mL) and carbonyldiimidazole (0.62 g, 3.73 mmol) was added at room temperature. After 2 d, the acetonitrile was evaporated in vacuo, the residue partitioned between 1N NaOH and dichloromethane, and the organic phase dried over magnesium sulfate. The crude product was purified by chromatography (silica gel, 1 to 20% methanol in methylene chloride gradient elution), which gave the title compound (0.15 g). MS 305.2.

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