A suspension of t-butyl 4-morpholinobenzylcarbamate (1.11 g, 3.80 mmol), bromoethynyl-triisopropyl-silane, CuI (225 mg, 1.17 mmol) and 1,10-phenantroline (250 mg, 1.40 mmol) in dry toluene (7.5 ml) was warmed to 90° C. under a nitrogen atmosphere. KHMDS (10 ml, 0.5 M in toluene) was added dropwise under nitrogen atmosphere and the mixture was stirred for 12 hours at this temperature. The reaction mixture was cooled to RT; Et2O (30 ml) and NaCl/NH4OH (60/30 ml) were added and the organic phase was extracted with Et2O (3×30 ml), washed with NaCl/NH4 and dried over Na2SO4. The solvent was removed under reduced pressure to afford the title compound which was purified by column chromatography (PE/AcOEt:95/5).
