A mixture of 4-benzyl-6-(4-bromo-phenyl)-[1,4]oxazepane (2.4 g, 6.9 mmol), potassium hexacyanoferrate(II) trihydrate (1.48 g, 3.5 mmol), palladium(II) acetate (1.6 mg, 0.007 mmol), diphenylphosphinoferrocene (7.8 mg, 0.014 mmol) and sodium carbonate (0.74 g, 7.0 mmol) in N-methylpyrrolidone (NMP) (7 mL) was prepared in a round bottom flask at room temperature under nitrogen atmosphere and the mixture was heated to 120° C. After stirring for 10 hours, the reaction mixture was cooled to room temperature and poured into water. The organic materials were extracted with ethyl acetate and wash with brine. The organic layer was separated and dried over anhydrous sodium sulfate. After concentration, the residual oil was passed through flash column chromatography on silica gel (hexane/ethyl acetate=90/10 to 50/50 as an eluant) to obtain pure 4-(4-benzyl-[1,4]oxazepan-6-yl)-benzonitrile (1.6 g, 5.5 mmol, 79%) as light yellow oil.
