Water → (+/-)-1-Methyl-3-(6-methyl-2-p-tolyl-imidazo[1,2-a]pyridin-3-yl)-piperidin-2-one

Beteiligte Stoffe

Reaktionsschritte

To a magnetically stirred solution of (±)-2-(6-methyl-2-p-tolyl-imidazo[1,2-a]pyridin-3-yl)-5-oxo-pentanoic acid methyl ester 35c (0.085 g, 0.253 mmol) in methanol (1 mL) at room temperature under Ar atmosphere was added a 40% aqueous solution of methyl amine (MeNH2) (0.021 mL, 0.253 mmol). The reaction mixture was stirred for 1 h at room temperature. NaBH4 (0.019 g, 0.506 mmol) was added at room temperature. After 30 min, water (30 mL) was added, and the aqueous phase was extracted with EtOAc (2×50 mL). The combined organic layers were dried (MgSO4), and concentrated in vacuo to the crude product. The pure product was obtained by column chromatography over silica gel (EtOAc, then 4:96 MeOH/EtOAc as eluent) which gave the title compound (0.03 g, 31%) as a white solid. The combined organic layers were washed with water, dried (MgSO4), and concentrated in vacuo to the crude product. 1H NMR (400 MHz, CDCl3) δ 1.99 (m, 3H), 2.11 (m, 1H), 2.31 (s, 3H), 2.38 (s, 3H), 3.05 (s, 3H), 3.41 (m, 1H), 3.53 (m, 1H), 4.25 (m, 1H), 6.99 (d, J=9.1 Hz, 1H), 7.22 (m, 3H), 7.46 (s, 1H), 7.53 (m, 2H). 13C NMR (100 MHz, CDCl3) δ 18.9, 21.5, 23.1, 26.1, 35.4, 39.7, 50.3, 117.4, 119.1, 121.5, 121.7, 127.0, 129.1, 129.3, 132.4, 137.5, 143.9, 144.4, 168.7. Mass spectrum m/e 335 (M+).

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