Triethylamine → 6-methoxy-1-methyl-7-[(2(S)-phenyl-piperidin-3(S)-ylamino)-methyl]-3,4-dihydro-1H-[1,5]naphthyridin-2-one

Beteiligte Stoffe

Reaktionsschritte

The 2-methoxy-5-methyl-6-oxo-5,6,7,8-tetrahydro-[1,5]naphthyridine-3-carbaldehyde prepared in step 5 (0.35 g; 1.4 mmol) was dissolved in 20 ml of dichloroethane. To this was added 250 mg (1.1 mmol) of 2-(S)-phenyl-piperidin-3(S)-ylamine and 0.4 ml (2.8 mmol) of triethylamine, and the mixture was stirred for 60 minutes at room temperature. To this mixture was added 0.7 g (3.3 mmol) of sodium triacetoxyborohydride, and the reaction mixture was stirred at room temperature for 18 hours. The reaction was quenched with water and stirred at room temperature for 30 minutes. The pH of the mixture was adjusted to 8.5 with Na2CO3. The organic layer was separated from the water layer. An additional 20 ml of water was added to the organic layer. The pH of the mixture was adjusted to 2 with 1N HCl and extracted with ethyl acetate. The pH of the water layer was adjusted to 7.5 with sodium bicarbonate and extracted with ethyl acetate. The pH=7.5 ethyl acetate extracts were combined, dried (Na2SO4), and evaporated to yield 300 mg of 6-methoxy-1-methyl-7-[(2(S)-phenyl-piperidin-3(S)-ylamino)-methyl]-3,4-dihydro-1H-[1,5]naphthyridin-2-one. 1H NMR (CDCl3) δ 7.2–7.4 (m, 5H), 6.85 (s, 1H), 3.90 (s, 1H), 3.85 (s, 3H), 3.60,3.38 (d,d 2H), 3.30 (d, 1H), 3.10 (s, 3H), 3.0 (s, 1H), 2.90 (m, 2H), 2.80 (m, 2H), 2.66 (m, 2H), 2.0–2.2 (m, 3H), 1.9 (m, 1H), 1.6 (m, 1H), 1.45 (m, 1H). Mass spectrum: m/e=381.1 (p+1). TLC: Rf=0.5; (5:1 chloroform/methanol).

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