Water → Rac-2-(tert-butoxycarbonylamino-methyl)-3-(3-fluoro-6-methoxy-[1,5]naphthyridin-4-yl)-propionic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

To a solution of LiHMDS (1M, 17 mL, 2.2 eq.), cooled to −78° C., was added dropwise a solution of 3-tert-butoxycarbonylamino-propionic acid ethyl ester (1.70 g, 7.82 mmol, prepared according to Tetrahedron Lett. (2003), 44, 2807-2811) in THF (20 mL). The solution was stirred at the same temperature for 90 min. A solution of 8-bromomethyl-7-fluoro-2-methoxy-[1,5]naphthyridine (2.12 g, 1 eq., prepared according to WO 2008/078305) in THF (10 mL) was quickly added and the reaction proceeded 2 h, keeping the internal temperature below −50° C. Water (100 mL) and EA (200 mL) were added. The two layers were decanted and the aq. layer was extracted with EA. The combined org. layers were washed with brine, dried over Na2SO4, filtered and concentrated to dryness. The residue was chromatographed (Hept-EA 2-1) to afford the title intermediate as a yellow oil (2.38 g, 75% yield).

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