Trifluoroacetic acid → 1-(6-(5-(2,6-difluorophenyl)-1H-indol-3-yl)pyrazin-2-yl)piperidin-3-amine

Participants

Reaction Steps

A glass microwave reaction vessel was charged with tert-butyl 5-(2,6-difluorophenyl)-3-iodo-1H-indole-1-carboxylate (350 mg, 0.769 mmol), tert-butyl 1-(6-(tributylstannyl)pyrazin-2-yl)piperidin-3-ylcarbamate (436 mg, 0.769 mmol), Pd(PPh3)4 (89 mg, 0.077 mmol), and CuI (15 mg, 0.077 mmol) in DMF (6 mL). The reaction mixture was stirred and heated in a Initiator microwave reactor (Personal Chemistry, Biotage AB, Inc., Uppsala, Sweden) at 100° C. for 30 min. The mixture was diluted with DCM and water. The organic layer was separated, washed with water and brine, dried over Na2SO4, filtered and concentrated to give the crude product, tert-butyl 3-(6-(3-(tert-butoxycarbonylamino)piperidin-1-yl)pyrazin-2-yl)-5-(2,6-difluorophenyl)-1H-indole-1-carboxylate. MS (ESI, pos. ion) m/z: 606 (M+1). To a solution of tert-butyl 3-(6-(3-(tert-butoxycarbonylamino)piperidin-1-yl)pyrazin-2-yl)-5-(2,6-difluorophenyl)-1H-indole-1-carboxylate (466 mg, 0.769 mmol) in DCM (6 mL) was added TFA (4 mL) and the reaction was stirred at RT for 3 h, then solvent was removed. The residue was diluted with DCM and washed with saturated NaHCO3 aqueous solution twice. The organic layer was dried over Na2SO4, filtered and concentrated. The residue was purified with RP-HPLC to give 1-(6-(5-(2,6-difluorophenyl)-1H-indol-3-yl)pyrazin-2-yl)piperidin-3-amine as a light brown solid. MS (ESI, pos. ion) m/z: 406 (M+1).

Provenance & Evidence