Triethylamine → ethyl 3-(1-acetyl-1H-indazol-5-yl)-3-oxopropanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-acetyl-1H-indazole-5-carboxylic acid (8.5 g, 41.63 mmol) in tetrahydrofuran (200 ml) was added CDI (20 g), and the resulting mixture was stirred for 2.5 h at 40° C., and then added dropwise to a solution of the magnesium salt of malonic acid monoethyl ester [prepared via the addition of Et3N (14 g, 138.25 mmol) and MgCl2 (19 g, 200 mmol) to a solution of potassium monoethylonate (24 g, 147.17 mmol) in acetonitrile (200 ml)] followed by stirring at room temperature for 2.5 h at 0° C. The resulting solution was stirred for an additional 2.5 h at 80° C. The reaction was then quenched by the addition of water (500 ml) and the pH adjusted to 3 with HCl (3N). The solids were collected by filtration and washed with water (3×50 ml) to afford ethyl 3-(1-acetyl-1H-indazol-5-yl)-3-oxopropanoate as a light yellow solid (8.6 g, 75%).

Provenance & Evidence