Phosphoric Acid → 1,5-Bis[4-(trifluoromethyl)phenyl]penta-1,4-dien-3-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-trifluoromethylbenzaldehyde (8.4 kg), heptane (12.1 L), water (5.23 L), 50% sodium hydroxide (0.384 kg) and methyl bis(hydroxyethyl)oleylammonium chloride (0.213 kg) is stirred under a nitrogen atmosphere and heated to 40° C. to 45° C. Acetone (1.44 kg) is added to the above mixture over 2.3 hours. The resulting slurry is stirred and heated at 42° C. for two hours and then 85% phosphoric acid (1.36 kg) is added followed by isopropyl alcohol (8.97 L). The resultant mixture is heated at reflux (73° C.) for 1.5 hours and then cooled to 14° C. The reaction mixture is filtered, the isolated solids washed with heptane (5.29 L) and water (7.12 L). Drying affords 7.2 kg of the title compound, mp 154° C. to 155.5° C.

Provenance & Evidence