Trifluoroacetic acid → methyl 4-[1-hydroxy-1-(1H-pyrazol-4-yl)ethyl]benzoate

Participants

Reaction Conditions

Reaction Steps

TFA (0.1 mL) in DCM (2 mL) were added dropwise to a mixture of methyl 4-[1-hydroxy-1-(1-trityl-1H-pyrazol-4-yl)ethyl]benzoate (0.2 g, 0.8 mmol), triethylsilane (0.2 mL) in DCM (5 mL) cooled to −40° C. Then the mixture was stirred at −40° C. for 2 hours. The mixture was adjusted to pH 7 by adding aqueous sodium bicarbonate solution at −40° C. After the reaction warmed to room temperature, the mixture was extracted with ethyl acetate. The organic layer was concentrated and the residue was purified by preparative thin layer chromatography to afford methyl 4-[1-hydroxy-1-(1H-pyrazol-4-yl)ethyl]benzoate. MS ESI calc'd. for C13H15N2O3 [M+H]+ 247. found 247. 1H NMR (400 MHz, CD3OD): δ 7.98 (d, J=8.4 Hz, 2H), 7.59 (d, J=8.4 Hz, 2H), 7.50 (s, 2H), 3.90 (s, 3H), 1.89 (s, 3H).

Provenance & Evidence