2,6-Lutidine → 4-Iodo-1-methyl-1H-pyrazole-5-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A round-bottom flash was charged with Preparation 20, 4-iodo-1-methyl-1H-pyrazole-5-carboxamide (222 g, 886 mmol) and DCM (2.22 L) and the reaction mixture was cooled to 0° C. 2,6-Lutidine (310 mL, 2.66 mol) and trifluoroacetic anhydride (253 mL, 1.77 mol) were added. After reaction was complete, saturated aqueous sodium bicarbonate (800 mL) was added and the layers separated. The aqueous layer was washed with DCM (800 mL). The organic layers were combined and washed with saturated aqueous ammonium chloride (800 mL), 1N HCl (800 mL), and brine (800 mL). The organic layer was dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was suspended in heptanes (˜2 L) and granulated at 0-5° C. for 30 min. The solid was collected via filtration and dried in a vacuum oven to afford 4-iodo-1-methyl-1H-pyrazole-5-carbonitrile as a colorless solid (196 g, 95% yield).

Provenance & Evidence