497 mg (1.25 mmol) of [2-(5-bromothiophen-2-yl)-imidazo[1,2-a]pyrazin-3-yl]-(1-phenyl-ethyl)-amine were dissolved together with 0.34 ml (3.13 mmol) of phenylacetylene, 43 mg (0.06 mmol) of bis(triphenylphosphine)-palladium(II) chloride and 24 mg (0.13 mmol) of copper(I) iodide in DMF (10 ml) After addition of 1.7 ml (12.5 mmol) of triethylamine, the mixture was stirred at 50° C. for 16 h. The reaction solution was then diluted with EA and combined with a sat. aq. sodium carbonate solution. The phases were separated and the aqueous phase extracted with EA. The combined organic phases were washed 2× with a sat. aq. sodium carbonate solution and 2× with a sat. aq. common salt solution and dried over magnesium sulfate. After filtration and removal of the solvents under a vacuum, column chromatography (EA/DCM 1:3) was carried out with the group, after which 158 mg (0.38 mmol, 30% of theoretical) of (1-phenyl-ethyl)-[2-(5-phenylethynyl-thiophen-2-yl)-imidazo[1,2-a]pyrazin-3-yl]-amine were obtained.
