Cesium carbonate → 3-({[tert-Butyl(diphenyl)silyl]oxy}methyl)benzyl 1-[3-({[tert-butyl(diphenyl)sily]oxy}methyl)benzyl]-5-chloro-1H-pyrrolo[3,2-b]pyridine-2-carboxylate

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Reaction Steps

5-Chloro-1H-pyrrolo[3,2-b]pyridine-2-carboxylic acid (0.803 g, 4.08 mmol, from Example 99, Step 1) in DMF (20 mL) was treated with Cs2CO3 (4.0 g, 12 mmol), followed by the addition of tert-butyl{[3-(chloromethyl)benzyl]oxy}diphenylsilane (3.9 g, 9.9 mmol, from Step 2). After stirring overnight, the crude reaction mixture was partitioned between water and ethyl acetate and the aqueous layer was extracted with an additional two portions of ethyl acetate. The combined organic extracts were washed sequentially with water and brine, dried over sodium sulfate, filtered and concentrated. The product was purified by flash chromatography, eluting with a slow gradient from 0-20% EtOAc/hexanes. Yield: (2.18 g, 58%).

Provenance & Evidence