反应详情

A stirred solution of ethyl 3-oxo-3-(2,3,4,5-tetrafluorophenyl)propionate (2.00 g, 7.57 mmol), Ac2O (4.29 mL, 45.4 mmol) and triethyl orthoformate (2.51 mL, 15.1 mmol) was heated at 120° C. for 3 hours. The mixture was concentrated in vacuo and dried under high vacuum. The crude product was dissolved in toluene (30 mL) and a suspension of (1-aminocyclobutyl)methanol (1.04 g, 7.57 mmol) in toluene (5 mL), triethylamine (1.06 mL, 7.57 mmol) were added under ice-cooling. The mixture was stirred for 18 h at room temperature and concentrated in vacuo to yield the crude product. The crude product was purified by column chromatography (Hexane:EtOAc 10:1→1:1) to yield the title compound (1.57 g, 55%) as a white solid. 1H-NMR (400 MHz, CDCl3) δ 0.95-1.11 (3H, m), 1.85-1.90 (1H, m), 1.91-2.07 (2H, m), 2.17-2.26 (2H, m), 2.27-2.36 (2H, m), 3.80-3.83 (2H, m), 4.00-4.10 (2H, m), 6.95-7.13 (1H, m), 8.17-8.22 (1H, m), 9.87-11.36 (1H, m). ESIMS (+): 376 [M+H]+.

1. concentrationThe mixture was concentrated in vacuo
2. customdried under high vacuum
3. dissolutionThe crude product was dissolved in toluene (30 mL)
4. additionwere added under ice-
5. temperaturecooling
6. concentrationconcentrated in vacuo
7. customto yield the crude product
8. customThe crude product was purified by column chromatography (Hexane:EtOAc 10:1→1:1)