Water → 2-(6-chloro-4-fluoro-1H-indazol-3-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde

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Reaction Conditions

Reaction Steps

2-Bromo-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde (7.6 g, 18.6 mmol) and 6-chloro-4-fluoro-3-tributylstannanyl-1H-indazole (crude from Step 3) were dissolved in DMF (180 ml) and purged with Ar gas. Tetrakis(triphenylphosphine)pallladium (1.07 g, 0.93 mmol) and then copper iodide (707 mg, 3.71 mmol) were added and the flask was stoppered and stirred in a 90° C. oil bath for 20 h. The reaction was cooled and water, ethyl acetate and sodium bicarbonate solution were added. The layers were separated, and the aqueous layer was extracted twice more with ethyl acetate. The combined organic layers were washed with water and sodium chloride solution, then dried over sodium sulfate. After evaporation, the residue was purified by silica gel chromatography (methanol/dichloromethane) followed by trituration with diethyl ether/hexanes to give 3.9 g (47%) of 2-(6-chloro-4-fluoro-1H-indazol-3-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carbaldehyde. (M+H)+=446.

Provenance & Evidence