反应详情

A mixture of 3-ethylaminomethyl-azetidine-1-carboxylic acid tert-butyl ester (200 mg, 1.0 mmol), dihydrofuran-3-one (0.155 mL, 2.0 mmol), diisopropylethylamine (0.347 mL, 2.0 mmol) and 4 Å molecular sieves (600 mg) in DCM (10 mL) was stirred at RT for 30 min. Sodium triacetoxyborohydride (424 mg, 2 mmol) was added and the resulting reaction mixture was stirred at RT under nitrogen atmosphere for 60 h. The suspension was filtered through Celite and the filtrate was concentrated in vacuo. The residue was purified by column chromatography (Si—PPC, MeOH:DCM, gradient 0:100 to 5:95) to afford the title compound as a colourless oil (257 mg, 95%). 1H NMR (400 MHz, CDCl3): δ 4.04-3.92 (3H, m), 3.83 (1H, dd, J=8.89, 6.90 Hz), 3.75 (1H, q, J=8.07 Hz), 3.64 (1H, dd, J=8.87, 6.21 Hz), 3.56-3.55 (2H, m), 3.14 (1H, m), 2.67-2.66 (2H, m), 2.51 (1H, dd, J=12.33, 7.20 Hz), 2.17 (3H, s), 2.05 (1H, s), 1.89-1.79 (1H, m), 1.44 (9H, s).

1. customthe resulting reaction mixture
2. stirringwas stirred at RT under nitrogen atmosphere for 60 h
3. filtrationThe suspension was filtered through Celite
4. concentrationthe filtrate was concentrated in vacuo
5. customThe residue was purified by column chromatography (Si—PPC, MeOH:DCM, gradient 0:100 to 5:95)