反应详情

温度

60 °C

to a stirred solution of 1-bromo-2-methyl-5-(methyloxy)-4-nitrobenzene (9 g, 36.6 mmol) in 180 mL of Dioxane was added Pd2(dba)2 (2.14 g, 2.34 mmol), XANTPHOS (2.12 g, 3.65 mmol), cesuim carbonte (50 g, 153.6 mmol) and 1,1-dimethylethyl 1-piperazinecarboxylate (13.6 g, 73.15 mmol). The resulting slurry was warmed to 60° C. for 24 hours. The dioxane was removed under reduced pressure and the crude mixture was taken up in ether and filtered to remove cesium carbonate. The ether was, washed with water, dried (Na2SO4), filtered, and rotovaped down. The crude product was purified by flash chromatography to give 1,1-dimethylethyl 4-[2-methyl-5-(methyloxy)-4-nitrophenyl]-1-piperazinecarboxylate (4.83 g, 13.75 mmol, 38%). 1H NMR (400 MHz, CDCl3) δ ppm 7.81 (s, 1 H), 6.56 (s, 1 H), 3.92 (s, 3 H), 3.52-3.63 (m, 4 H), 2.88-2.99 (m, 4 H), 2.25 (s, 3 H), 1.47 (s, 9 H).

1. customThe dioxane was removed under reduced pressure
2. filtrationfiltered
3. customto remove cesium carbonate
4. washwashed with water
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. customThe crude product was purified by flash chromatography