6-chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridine-4-carbaldehyde → 1-(6-chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridin-4-yl)ethanol

Participants

Reaction Conditions

Reaction Steps

Chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridine-4-carbaldehyde (Intermediate 11B, 535 mg, 1.2 mmol) was dissolved in THF (8 ml) cooled to −78° C. and charged with methylmagnesium bromide (3M, 0.786 ml, 2.357 mmol). The reaction was allowed to stir for 1 hr, eventually reaching 0° C. The reaction was slowly quenched with saturated ammonium chloride (3 mL) and partioned between EtOAc 2×10 mL, washed with brine, dried over MgSO4, filtered, and concentrated in vacuo. The residue was then loaded onto silica gel and purified by MPLC 0-25% EtOAc/hexanes to provide 1-(6-chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridin-4-yl)ethanol (38B). MS: [M+H]+ m/z 470.

Provenance & Evidence