Hydrochloric Acid → N-tert-butyl-2-(5-(thiophen-3-ylethynyl)thiophen-2-yl)imidazo[1,2-a]pyrazin-3-amine hydrochloride

Participants

Reaction Conditions

Reaction Steps

94 mg (0.5 mmol) of copper(I) iodide, 129 mg (0.5 mmol) of triphenylphosphine, 1.32 ml (9.5 mmol) of NEt3, 701 mg (1.9 mmol) of tetra-n-butyl-ammonium iodide and 173 mg (0.25 mmol) of bis(triphenylphosphine)-palladium(II) chloride were added to a solution of 699 mg (1.9 mmol) of tert-butyl-[2-(5-trimethylsilanylethynyl-thiophen-2-yl)-imidazo[1,2-a]pyrazin-3-yl]-amine (synthesis described in Example 158, part a) and 402 mg (2.5 mmol) of 3-bromo-thiophene in DMF (20 ml). 2.5 ml (2.5 mmol) of a 1M solution of tetra-n-butyl-ammonium fluoride in THF were added dropwise to the reaction solution over a period of 1 h. The mixture was then stirred at 70° C. for 18 h. After cooling to RT, the mixture was diluted with EA and combined with a 0.5M aq. Na2CO3 solution. The phases were separated and the aq. phase was extracted with EA. The combined organic phases were dried over MgSO4, filtered and evaporated under a vacuum. CC (acetonitrile/EA 1:3) was carried out with the group, 912 mg of slightly contaminated product being isolated. 304 mg (0.73 mmol, 38%) of N-tert-butyl-2-(5-(thiophen-3-ylethynyl)thiophen-2-yl)imidazo[1,2-a]pyrazin-3-amine hydrochloride were obtained by hydrochloride precipitation in accordance with the method described in Example 192.

Provenance & Evidence