Trifluoroacetic acid → Ethyl 1-benzyl-3-cyanopyrrolidine-3-carboxylate

関与物質

反応手順

TFA (4.31 mmol, 0.49 g) was added to a solution of ethyl 2-cyanoacrylate (17.58 mmol, 2.20 g) in DCM (100 mL) under nitrogen atmosphere. Subsequently, a solution of N-benzyl-1-methoxy-N-((trimethylsilyl)methyl)methanamine (21.49 mmol, 5.10 g) in DCM (50 mL) was added dropwise while cooling with an ice-bath in order to keep the reaction temperature at room temperature (exothermic reaction). The reaction mixture was stirred overnight at room temperature. Then the mixture was washed with saturated aqueous NaHCO3 (100 mL). The aqueous phase was extracted with DCM (100 mL). The combined organic phase was dried over MgSO4 and evaporated in vacuo. The crude product was purified by flash silicagel chromatography (100% heptane to 50% EtOAc) yielding 4.27 g of a colorless oil (94%). 1H-NMR (400 MHz, CDCl3, 300K): δ=1.32 (3H, t, J=7.1 Hz), 2.44 (1H, m), 2.59 (1H, m), 2.69 (1H, m), 2.89 (1H, m), 2.99 (1H, d, J=9.8 Hz), 3.17 (1H, d, J=9.8 Hz), 3.69 (2H, s), 4.27 (2H, q, J=7.1 Hz), 7.29 (5H, m).

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