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

Participants

Reaction Steps

A 20% solution of sodium ethoxide in ethanol (29.7 g) was combined at 0C with diethyl malonate (14.0 g) and then with 4-(5-fluoro-2-methylphenyl)-3-buten-2-one (13.4 g) in portions. The reaction mixture was stirred at room temperature for 30 minutes, and then stirred with heating for 2 hours. After allowing to stand to cool, the solvent was distilled off, and the residue was combined with water and the aqueous layer was washed with ethyl acetate and then concentrated. 2M Sodium hydroxide (46 ml) was added and the mixture was heated under reflux for 1 hour. After allowing to stand to cool, 2.5M sulfuric acid (46 ml) was added over 10 minutes, and the mixture was heated under reflux for 30 minutes. After allowing to stand to cool, the precipitated crystal was recovered by a filtration and washed successively with water and isopropyl ether to obtain 5-(5-fluoro-2-methylphenyl)cyclohexane-1,3-dione (8.6 g) as a colorless crystal.

Provenance & Evidence