n-Butyllithium (1.6 M solution in hexanes, 0.980 mL, 1.57 mmol) was added dropwise over about 10 min to a slurry of (methoxymethyl)triphenylphosphonium chloride (0.550 g, 1.60 mmol) and THF (3.00 mL) under N2 at about −78° C. After about 5 min, the reaction vessel was transferred to an ice water bath. After stirring for about 10 min at about 0° C., the dark red reaction mixture was cooled to about −78° C. A solution of tert-butyl (4-(1-(4-bromophenyl)-3-oxopropyl)-1-ethyl-3-(pyridin-2-yl)-1H-pyrazol-5-yl)carbamate (0.161 g, 0.168 mmol) and THF (1.50 mL) was added over about 5 min. After about 5 min, the reaction mixture was transferred to an ice bath. After about 1 h, saturated aqueous NaHCO3 (5 mL) and EtOAc (5 mL) were added respectively. The ice bath was removed. The layers were separated and the aqueous layer was extracted with EtOAc (5 mL). The combined organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified on silica gel using a gradient of 10-50% EtOAc in heptane. The fractions containing product were combined and concentrated under reduced pressure to afford tert-butyl (4-(1-(4-bromophenyl)-4-methoxybut-3-en-1-yl)-1-ethyl-3-(pyridin-2-yl)-1H-pyrazol-5-yl)carbamate (0.0726 g, 0.138 mmol, 82%) as an ivory solid. Compound was about a 2.2:1 mixture of olefin isomers. LC-MS (Table 1, Method g) Rt=2.83 min; m/z 527 and 529 (M+H)+(Major) and Rt=2.87 min; m/z 527 and 529 (M+H)+ (Minor).
