Pyrazole → 3-chloro-6-(1H-pyrazol-1-yl)pyridazine

Participants

Reaction Steps

To a solution of pyrazole (3.69 g, 25 mmol, 1.0 equiv) in NMP (25 mL) was added sodium hydride (60% dispersion in mineral oil, 1.5 g, 38 mmol, 1.5 equiv). The mixture was stirred for 15 min, followed by the addition of 3,6-dichloropyridazine (3.02 g, 25 mmol, 1.0 equiv). The reaction mixture was stirred for 1.5 h and then diluted with water (50 mL) and ethyl acetate (100 mL). After transferring to a separatory funnel and shaking, the organic layer was separated from the aqueous layer and then washed with brine (3×50 mL). The organic layer was then dried over Na2SO4, filtered, and concentrated to give 3.89 g of 3-chloro-6-(1H-pyrazol-1-yl)pyridazine as a crude tan solid that was used directly in the next step.

Provenance & Evidence