Ethyl bromoacetate → ethyl 4-[1-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[4,3-b]pyridin-4-yl]-3-[5-methyl-3-(trifluoromethyl)pyrazol-1-yl]-4-oxo-butanoate

Participants

Reaction Conditions

Reaction Steps

To a mixture of 1-[1-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[4,3-b]pyridin-4-yl]-2-[5-methyl-3-(trifluoromethyl)pyrazol-1-yl]ethanone (0.150 g, 0.37 mmol) in THF (4 ml) at −78° C. was added LDA (0.247 mL, 0.50 mmol, 2 M in THF). After stirring for 10 min at −78° C., ethyl bromoacetate (0.061 mL, 0.55 mmol) was added. The mixture was then warmed to rt for 10 min and quenched with sat. NH4Cl. The mixture was partitioned between EtOAc (50 mL) and brine (30 mL). The organic layer was separated, dried over Na2SO4, concentrated in vacuo and purified by flash chromatography (SiO2 with a gradient elution of 0-60% EtOAc/hexanes) to afford ethyl 4-[1-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[4,3-b]pyridin-4-yl]-3-[5-methyl-3-(trifluoromethyl)pyrazol-1-yl]-4-oxo-butanoate (0.120 g, 83%).

Provenance & Evidence