Triphenylphosphine → {1-[2-(4-Benzyloxy-6-methoxy-[1,5]naphthyridin-3-yloxy)-ethyl]-piperidin-4-yl}-carbamic acid tert-butyl ester

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Reaction Steps

Diethyl azodicarboxylate (5.48 g, 31.46 mmol, 2.0 eq) is added at room temperature to a stirred solution of 4-benzyloxy-6-methoxy-[1,5]naphthyridin-3-ol (4.44 g, 15.73 mmol, 1.0 eq), [1-(2-hydroxy-ethyl)-piperidin-4-yl]-carbamic acid tert-butyl ester (5.76 g, 23.59 mmol, 1.5 eq) and triphenylphosphine (8.25 g, 31.46 mmol, 2.0 eq) in tetrahydrofuran (150 mL). After 15 hours stirring at room temperature, tetrahydrofuran is evaporated and the resulting crude product is purified by column chromatography (silica gel, eluent: ethyl acetate:methanol, 10:0 to 9:1, v/v) to afford {1-[2-(4-benzyloxy-6-methoxy-[1,5]naphthyridin-3-yloxy)-ethyl]-piperidin-4-yl}-carbamic acid tert-butyl ester as a light brown viscous oil (9.31 g, 88% yield).

Provenance & Evidence