Cesium carbonate → cis-3,5-Dimethyl-1-[4-(methyloxy)-3-nitrophenyl]piperazine

Participants

Reaction Steps

Palladium (II) acetate (941 mg, 4.2 mmol) and rac-2,2′-bis(diphenylphosphino)-1,1′-binapthyl (3.93 g, 6 mmol) were heated to 50° C. in dioxane (200 ml) for 30 minutes. Cesium carbonate (20.48 g, 63 mmol), 4-bromo-2-nitroanisole (9.75 g, 42 mmol) and cis-2,6-dimethylpiperazine (14.39 g, 126 mmol) were added and the mixture heated at reflux for 18 hours. The solids were filtered through celite and washed with ethyl acetate. The residue was concentrated and dissolved in ethyl acetate and extracted with 2N hydrochloric acid (×5). The combined extracts were washed in ethyl acetate (×3), basified with 0.880 ammonia and extracted with dichloromethane (×5). The combined organic extracts were concentrated, redissolved in ethyl acetate and washed with water (×3), saturated brine, dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography (Biotage Horizon, dichloromethane to 1:9 2M ammonia in methanol:dichloromethane) to afford the title product (D3). MS (ES+) m/e 266 [M+H]+.

Provenance & Evidence