Dimethylformamide → ethyl 4-iodo-1-(4-methoxybenzyl)-5-methyl-1H-pyrazole-3-carboxylate

Participants

Reaction Steps

To a stirred solution of ethyl 4-iodo-5-methyl-1H-pyrazole-3-carboxylate (Step 1.1) (7.60 g, 27.1 mmol) in DMF (50 mL) under Ar was added NaH (1.302 g, 32.6 mmol) at 0° C. After 15 min, 4-methoxyphenyl chloride (3.70 mL, 27.1 mmol) was added. The reaction mixture was stirred for 1 hr at rt, quenched with a saturated aqueous solution of NaHCO3 (100 mL) and extracted with EtOAc (100 mL). The combined organic layers were washed with a saturated aqueous solution of NaHCO3 (100 mL), dried over Na2SO4 and the solvent was evaporated off under reduced pressure. The crude material was purified by silica gel column chromatography (hexane/EtOAc 5-40%) to afford the title product (6.23 g, 15.57 mmol, 57% yield) as a colorless oil. tR: 5.24 min (HPLC 1); tR: 1.12 min (LC-MS 2); ESI-MS: 401 [M+H]+ (LC-MS 2); Rf=0.66 (hexane/EtOAc 1:1).

Provenance & Evidence