反应详情

To a solution of 5-hydroxy-2H-pyrazole-3-carboxylic acid methyl ester (2.3 g, 16 mmol) in DMF (10 mL) at room temperature was added cesium carbonate (5.27 g, 16 mmol) and methyl iodide (2.3 g, 1.0 mL, 16 mmol) and the resulting mixture stirred for 2.5 h. The mixture was then filtered off to afford the title compound (434 mg, 17%) as a white solid after trituration with ethyl acetate. MS: m/e=157.2 [M+H]+.

1. filtrationThe mixture was then filtered off