Diethyl Malonate → 5-(2-Fluoro-5-methylphenyl)cyclohexane-1,3-dione

Participants

Reaction Steps

To a solution of 20% sodium ethoxide in ethanol (1.4 g) was added at room temperature diethyl malonate (3.3 g) and then was added little by little 4-(2-fluoro-5-methylphenyl)-3-buten-2-one (3.5 g), and the reaction mixture was stirred at room temperature for 30 minutes, refluxed for 2 hours and cooled. The solvent was evaporated, and to the residue was added water. The aqueous layer was washed with ethyl acetate and concentrated. To the residue was added 2M sodium hydroxide (11 ml), and the mixture was refluxed for 2 hours and cooled. To the mixture was added 2.5M sulfuric acid (11 ml) for 5 minutes, and the mixture was refluxed for 30 minutes and cooled. Precipitated crystals were filtered, washed with water and isopropylether to give 5-(2-fluoro-5-methylphenyl)cyclohexane-1,3-dione (1.6 g) as colorless crystals.

Provenance & Evidence