C(P(C(C)(C)C)C(C)(C)C)(C)(C)C.[CH3:14][N:15]([CH3:19])[CH2:16][C:17]#[CH:18].C(NC(C)C)(C)C.Br[C:28]1[CH:33]=[CH:32][C:31]([N+:34]([O-:36])=[O:35])=[CH:30][CH:29]=1>O1CCOCC1.[Cu]I.C1C=CC(C#N)=CC=1.C1C=CC(C#N)=CC=1.Cl[Pd]Cl>[CH3:14][N:15]([CH3:19])[CH2:16][C:17]#[C:18][C:28]1[CH:33]=[CH:32][C:31]([N+:34]([O-:36])=[O:35])=[CH:30][CH:29]=1Tri-t-butylphosphine (0.25 M in dioxane, 11.9 ml, 3.0 mmol, 0.2 eq.), 3-dimethylamino-1-propyne (2.2 ml, 20.8 mmol, 1.4 eq.), and diisopropylamine (2.7 ml, 19.3 mmol, 1.3 eq.) are added sequentially to a mixture of 4-bromonitrobenzene (3 g, 14.9 mmol), copper (I) iodide (198 mg, 1.0 mmol, 0.07 eq.), and Pd(PhCN)2Cl2 (570 mg, 1.5 mmol, 0.1 eq.) in dioxane (20 ml), under an argon atmosphere. The resulting mixture is stirred for 22 h at RT and concentrated. The residue is dissolved in EE and water and filtered through a pad of celite. The aqueous layer is separated and extracted with EE. The organic phase is washed with brine, dried (sodium sulfate), filtered and concentrated. Purification of the residue by silica gel column chromatography (DCM/MeOH+1% NH3aq, 95:5) affords 2.72 g of the title compound as a brown oil: ESI-MS: 205.0 [MH]+; tR=2.51 min (purity: 100%, gradient J); TLC: Rf=0.41 (DCM/MeOH+1% NH3aq, 95:5).
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