Potassium Phosphate, Tribasic → 2-(1,3-dimethyl-1H-pyrazol-4-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

In a 25 mL pressure vessel, 1,3-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (439 mg, 1.98 mmol), lithium chloride (52 mg, 1.23 mmol) and 2-bromo-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde (440 mg, 1.23 mmol) were combined with ethanol (7 mL) and toluene (7 mL) and the mixture was purged with N2. Potassium phosphate tribasic (917 mg, 4.32 mmol) was dissolved in 4 mL water and added to the mixture. After more purging with N2 bis(triphenylphosphine)palladium (II) dichloride (87 mg, 0.12 mmol) was added, the vessel capped and stirred at 60-65° C. for 20 h. The reaction was cooled, then diluted with ethyl acetate and water. The organic layer was washed with brine, dried and evaporated. The crude material was purified by flash chromatography (silica gel, 80 g, 100% EtOAc to 20% THF/EtOAc) to give 360 mg (71% yield; 90% purity) of 2-(1,3-dimethyl-1H-pyrazol-4-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde.

Provenance & Evidence