Br[C:2]1[CH:16]=[CH:15][C:5]2[N:6]([CH:9]3[CH2:14][CH2:13][CH2:12][CH2:11][O:10]3)[CH:7]=[N:8][C:4]=2[CH:3]=1.[CH:17]([O:19]CCCC)=[CH2:18].[O-]P([O-])([O-])=O.[K+].[K+].[K+]>Cl[Pd]Cl.CC(O)C>[O:10]1[CH2:11][CH2:12][CH2:13][CH2:14][CH:9]1[N:6]1[C:5]2[CH:15]=[CH:16][C:2]([C:17](=[O:19])[CH3:18])=[CH:3][C:4]=2[N:8]=[CH:7]1A mixture of 80 (2.81 g, 0.01 mol), butyl vinyl ether (1.5 g, 0.015 mol), PdCl2 (26 mg, 0.14 mmol), (o-tolyl)3P (88 mg, 0.29 mmol), K3PO4 (1.5 g, 0.02 mol), and IPA (20 ml) was heated at reflux under nitrogen overnight. The mixture was cooled to RT and the solvent was removed in vacuo. To the residue was added 6M HCl (60 mL) and the resulting solution stirred for 15 min. The mixture was adjusted to pH 8 with aqueous NH4OH (35%) and was extracted with EtOAc (300 mL). The organic layer was washed with brine (50 mL), dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by SiO2 chromatography eluting with a DCM/MeOH gradient (5 to 10% MeOH) to afford 1.2 g (86%) of 1-(1-(tetrahydro-2H-pyran-2-yl)-1H-benzo[d]imidazol-5-yl)ethanone (82) as yellow oil: MS (ESI) m/z=245.3 (M+1).
Loading…
