Carbon Dioxide → 2-[2-(3,5-dimethoxyphenyl)ethyl]-6-[4-(4-methylpiperazin-1-yl)phenyl]-5-{[2-(trimethylsilyl)ethoxy]methyl}-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid

Participants

Reaction Steps

The a stirred solution of 7-bromo-2-[2-(3,5-dimethoxyphenyl)ethyl]-6-[4-(4-methylpiperazin-1-yl)phenyl]-5-{[2-(trimethylsilyl)ethoxy]methyl}-5H-pyrrolo[2,3-b]-pyrazine (55 mg, 82.7 μmol) in tetrahydrofuran (2 mL), n-butyllithium (2.5 M in hexanes, 50 μL, 0.125 mmol) was added at 78° C. After 10 minutes, dry CO2 (prepared by passing the CO2 through drying tube) was bubbled into the reaction. After 20 minutes, the reaction was quenched with saturated aqueous NH4Cl, then extracted with methylene chloride. The combined organic layers were dried over MgSO4, then concentrated to give the crude product (50 mg), which was used directly in the next step. LCMS calculated for C34H46BN5O5Si (M+H)+: m/z=632.3. Found: 632.3.

Provenance & Evidence