Cesium carbonate → 5-iodo-1-pyridin-3-yl-1H-indazole

Beteiligte Stoffe

Reaktionsschritte

Cesiumcarbonate (26.84 g, 82.38 mmol) is added to a suspension of 2-fluoro-5-iodobenzaldehyde (6.87 g, 27.46 mmol) and 3-pyridylhydrazine dihydrochloride (5 g, 27.46 mmol) in 136 mL N-methylpyrrolidon. The reaction mixture is stirred overnight at room temperature. After checking that the hydrazone has been formed (1H-NMR) the reaction mixture is heated for four hours at 160° C. The reaction mixture is allowed to cool down and the dark brown suspension is poured on 1000 mL ice water. After vigorously stirring at room temperature for 45 minutes, the precipitated product is sucked off via a glass microfibre filter, washed with water and dried at the evaporator at 45° C. 8.28 g (93.9%) of the title compound are obtained.

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