反应详情

To a solution of (E3) (1.0 eq.) in dry DCM (0.4 M) at 0° C. was added nitrosonium tetrafluoroborate (1.3 eq.) portionwise. After 1 h at 0° C. dry dichlorobenzene (120 eq.) was added and the reaction was slowly heated to 160° C. while DCM was distilled off. After 3 hrs, the mixture was cooled to RT, EtOAc was added and the organic phase was washed with brine (2×). After drying over MgSO4, the solvents were removed under reduced pressure. The crude was purified by flash chromatography using 1-10% EtOAc/petroleum ether to yield (E4) as a yellow oil. 1H NMR (400 MHz, CDCl3, 300K) δ 7.42 (1H, m), 7.06 (1H, m), 3.92 (3H, s), 2.30 (3H, d, J=2.3 Hz).

1. distillationwas distilled off
2. additionEtOAc was added
3. washthe organic phase was washed with brine (2×)
4. dry with materialAfter drying over MgSO4
5. customthe solvents were removed under reduced pressure
6. customThe crude was purified by flash chromatography