Diisopropylethylamine → 6-chloro-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazolo[3,4-b]pyridine 6-chloro-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-pyrazolo[3,4-b]pyridine

Participants

Reaction Steps

6-chloro-1H-pyrazolo[3,4-b]pyridine (500 mg, 3.3 mmol) was suspended in DCM (10 mL) and N,N-diisopropylethylamine (1.7 mL, 9.8 mmol) was added followed by 2-(trimethylsilyl)ethoxymethyl chloride (1.2 mL, 6.78 mmol). After stifling 3.5 h, the reaction mixture was diluted with EtOAc and water. The organic phase was dried over Na2SO4, filtered, and concentrated to afford a crude residue that was purified by silica gel chromatography (5-50% EtOAc in hexanes) to provide 610 mg of the first-eluting isomer 6-chloro-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazolo[3,4-b]pyridine (or 6-chloro-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-pyrazolo[3,4-b]pyridine, regiochemistry not determined) 7.54. Uncertainty in this assignment is implicit in other depictions of Intermediate 7.54. LCMS-ESI+ (m/z): [M+H]+ calcd for C12H19ClN3OSi: 284.10; found: 283.79.

Provenance & Evidence