Ammonium Chloride → (5-chloro-1-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl)(4-chloro-2-methylphenyl)methanol

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Reaction Steps

5-chloro-1-methyl-3-(pyridin-2-yl)-1H-pyrazole-4-carbaldehyde (16.38 g, 73.9 mmol) in THF (350 mL) was cooled to about −40 to −50° C. then 0.5 M (4-chloro-2-methylphenyl)magnesium bromide in THF (163 mL, 81 mmol) was added dropwise over about 15 min. The mixture was allowed to warm to rt then cooled in an ice bath. Saturated aqueous NH4Cl (400 mL) was added then the mixture was extracted with EtOAc (2×300 mL). The organic layer was washed by brine (400 mL), dried over Na2SO4, filtered and concentrated in vacuo to give (5-chloro-1-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl)(4-chloro-2-methylphenyl)methanol (25.7 g, 100%): LC-MS (Table 1, Method g) Rt=2.49 min, m/z 348/350 (M+H)+; 1H-NMR (DMSO, Bruker 400 MHz) δ 8.56 (d, J=5.0 Hz, 1H), 8.03 (d, J=8.1 Hz, 1H), 7.96-7.90 (m, 1H), 7.40-7.36 (m, 1H), 7.22-7.16 (m, 3H), 7.09-7.05 (m, 1H), 6.23 (d, J=7.8 Hz, 1H), 3.87 (s, 3H), 2.26 (s, 3H).

Provenance & Evidence