2-Ethylbutyraldehyde → 2-ethyl-1-{1-[(4-methylphenyl)sulfonyl]-1H-pyrazol-5-yl}butan-1-ol

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Reaction Steps

To 1-[(4-methylphenyl)sulfonyl]-1H-pyrazole (0.50 g, 2.26 mmol) [J Chem. Res., Synopses, 10, 327 (1979)] in THF (23 mL) at −78° C. was added a solution of t-butyllithium (1.7 M in pentane, 1.5 mL, 2.49 mmol) dropwise. After 10 min 2-ethylbutyraldehyde (0.31 mL, 2.49 mmol) was added. After 10 min the reaction mixture was quenched with saturated aqueous ammonium chloride (5 mL) and then diluted with H2O (30 mL) and extracted with EtOAc (3×30 mL). The organic extract was dried (Na2SO4) and concentrated. The residue was purified by column chromatography (EtOAc/hexane, 3:7) to give 0.546 g (75%) of 2-ethyl-1-{1-[(4-methylphenyl)sulfonyl]-1H-pyrazol-5-yl}butan-1-ol.

Provenance & Evidence