反应详情

温度

50 °C

To a mixture of 302a (170 mg, 1 mmol) in methanol (4 mL), ZnCl2 (1 mmol/L in diethyl ether) (2 mL, 2 mmol) and oxetan-3-one (150 mg, 2 mmol) were added at room temperature under nitrogen protection, followed by the addition of NaBH3CN (130 mg, 2 mmol). The reaction mixture was warmed to 50° C. and stirred for 3 h. The mixture was then cooled to room temperature and the solvent was removed. The residue was purified on flush column eluting with 50:1 methylene chloride/methanol to afford 302b as a yellow solid (180 mg, 80%, two steps). LCMS: (M+H)+ 227. 1H NMR (500 MHz, DMSO) δ 6.99 (s, 1H), 4.52 (t, J=6.5, 2H), 4.42 (t, J=6, 2H), 3.98 (s, 3H), 3.63 (m, 1H), 3.50 (s, 2H), 2.03 (s, 3H).

1. additionwere added at room temperature under nitrogen protection
2. temperatureThe mixture was then cooled to room temperature
3. customthe solvent was removed
4. customThe residue was purified
5. customon flush column
6. washeluting with 50:1 methylene chloride/methanol