Acetic Acid → tert-Butyl 4-(2-oxo-2,3-dihydro-1H-indol-1-yl)piperidine-1-carboxylate

Beteiligte Stoffe

Reaktionsschritte

Methyl 2-aminophenylacetate (3.0 g, 18.2 mmol) and 1-tert-butoxycarbonyl-4-piperidone (4.5 g, 22.6 mmol) were set stirring in 50 mL of CH2Cl2 under an atmosphere of nitrogen. Sodium triacetoxyborohydride (5.4 g, 25.5 mmol) was added followed by 1 mL of acetic acid. After 20 h at rt the mixture was quenched by the slow addition of saturated NaHCO3. After stirring for 30 min, the organics were separated, dried (MgSO4), and evaporated to afford 7.5 g of a purple oil. Purification by column chromatography (silica, 10-50% EtOAc/hexanes) gave 3.9 g (62%) of the title compound. TLC (silica, 25% EtOAc/hexanes): Rf=0.15. 1H NMR (400 MHz, CDCl3): 7.25 (m, 2H), 7.01 (m, 2H), 4.40 (m, 1H), 3.53 (s, 2H), 2.83 (m, 2H), 2.32 (m, 2H), 1.70 (m, 2H), 1.51 (s, 9H).

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