Cesium carbonate → Tert-butyl 4-(4-(1,3-dioxoisoindolin-2-yl)-3-nitrophenyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

2-(4-bromo-2-nitrophenyl)isoindoline-1,3-dione (500 g, 1.4 mmol), tert-butyl piperazine-1-carboxylate (402 g, 2.2 mmol), Pd2(dba)3 (66.0 g, 0.07 mmol), Xantphos (83 g, 0.144 mmol) and Cs2CO3 (939 g, 2.9 mmol) were placed in reaction vial (microwave reaction vial 10-20 ml) and purged with nitrogen. Toluene (5.0 ml) was added and nitrogen was bubbled for 10 min. The reaction mixture was heated at 100° C. for 5 hours. Heating was stopped and cooled to rt. The reaction mixture was filtered through a pad of celite and filtrate was evaporated. The remaining material was purified by flash chromatography on silica eluting with 20% to 70% EtOAc/Hexane to afford the title compound (275 mg, yield: 42%). 1H-NMR (400 MHz, CDCl3) δ 1.51 (s, 6H) 3.28-3.39 (m, 2H) 3.57-3.70 (m, 2H) 7.20-7.24 (m, 1H) 7.35 (d, 1H) 7.66 (d, 1H) 7.75-7.87 (m, 1H) 7.96 (dd, 1H)

Provenance & Evidence