II.[CH2:3](Br)[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.[CH2:11]([O:13][C:14](=[O:22])[C:15]1[CH:20]=[C:19](Br)[CH:18]=[N:17][CH:16]=1)[CH3:12].C([O-])(O)=O.[Na+]>CC(N(C)C)=O.C1C=CC=CC=1.CCOC(C)=O.[Zn]>[CH2:11]([O:13][C:14](=[O:22])[C:15]1[CH:20]=[C:19]([CH2:3][C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=2)[CH:18]=[N:17][CH:16]=1)[CH3:12]
A suspension of Zn (1.0 g, 15 mmol) and I2 (130 mg, 0.5 mmol) in DMA (15 mL) was stirred vigorously until the red color dissipated (3-5 min). Benzyl bromide (1.7 g, 10 mmol) was introduced and the resulting slurry was heated at 80° C. for 2.5 h at which point Cl2Pd(PPh3)2 (250 mg, 0.35 mmol) and a solution of ethyl-5-bromonicotinate (1.1 g, 5.0 mmol) in benzene (10 mL) were introduced and the reaction was heated at 80° C. for 1 h. The reaction was allowed to cool to room temperature and was diluted with EtOAc (100 mL). The mixture was poured into NaHCO3 (5% aqueous, 100 mL). The layers were separated and the aqueous layer was extracted with EtOAc (2×50 mL). The combined organic layers were sequentially washed with H2O (3×100 mL) and brine before being dried over Na2SO4. Concentration and purification by silica gel chromatography (hexane→50% EtOAc/hexane) provided the title compound as a brown oil. MS m/z: 242.1 (M+1).
Wird geladen…
