Diisopropylamine → 2-[5-(5-Bromo-pyridin-2-ylethynyl)-indol-1-yl]-ethanol

Participants

Reaction Conditions

Reaction Steps

Under an N2 atmosphere 29.4 g (124 mmol) 2,5-dibromo-pyridine, 241 mg (1.3 mmol) CuI and 888 mg (1.3 mmol) Pd(PPh3)2Cl2 are added to a solution of 23.0 g (124 mmol) 2-(5-ethynyl-indol-1-yl)-ethanol and 35 mL (248 mmol) diisopropylamine in 1150 mL THF and the reaction mixture is heated to 50° C. for 3.5 h. Another 241 mg CuI and 888 mg Pd(PPh3)2Cl2 and 9 g (38 mmol) 2,5-dibromo-pyridine are added, the mixture is stirred for a further 2.5 h at 50° C., 64 h at RT and a further 8 h at 60° C. The mixture is evaporated down i. vac., the residue is combined with 500 mL 3% NH3 solution and 800 mL EtOAc. The precipitate formed is filtered off, washed with water and dried at 50° C. The two phases of the filtrate are separated and the organic phase is evaporated down i.vac. The residue is stirred vigorously with 500 mL PE/diisopropylether (1:1) and suction filtered. The two product fractions are then combined.

Provenance & Evidence