反应详情

7-Ethoxycarbonylmethyl-3,4-dihydro-2H-[1,8]naphthyridine-1-carboxylic acid tert-butyl ester (synthetic methodology described in WO 00/33838) (6.11 g, 19.0 mmol) was dissolved in tetrahydrofuran (40 ml) at room temperature. The solution was place under argon. Lithium borohydride [2M in tetrahydrofuran](22.8 mmol, 11.43 mL) was carefully added and the reaction was refluxed overnight (16 h). The mixture was poured into a solution of saturated ammonium chloride and extracted with ethyl acetate. The organic layer was dried over Na2SO4, filtered, and evaporated under vacuum to give a crude mixture, which was purified via column chromatography to give 7-(2-hydroxy-ethyl)-3,4-dihydro-2H-[1,8]naphthyridine-1-carboxylic acid tert-butyl ester (49% yield). 1H NMR (Cl3CD), δ: 7.30 (d, 1H, J=7.6 Hz), 7.76 (d, 1H, J=7.6 Hz), 3.98 (m, 2H), 3.78 (m, 2H), 2.92 (m, 2H), 2.71 (m, 2H), 1.92 (m, 2H), 1.54 (s, 9H).

1. temperaturethe reaction was refluxed overnight (16 h)
2. extractionextracted with ethyl acetate
3. dry with materialThe organic layer was dried over Na2SO4
4. filtrationfiltered
5. customevaporated under vacuum
6. customto give a crude mixture, which
7. customwas purified via column chromatography