Hydrochloric Acid → Cinnamoylbenzene

Participants

Reaction Steps

A solution of 4.92 g (36.1 mmol) of 2-hydroxyacetophenone, 3.30 g (34.2 mmol) of ,4'-(α-methyl)ethenyl, biphenyl 4-carboxaldehyde and 8.15 g NaOH (in 15 ml of water) in 100 ml of ethanol was stirred for 12 hours before the solution was poured into 400 ml of water. The resulting mixture was neutralized with dilute HCl to yield a chalcone. The yellow precipitate obtained was filtered and dried. The chalcone was purified by recrystallized from methylene chloride. Further oxidation of above chalcone was carried out with excess of H2O2 (30%) in ethanol under basic conditions for 12 hours. The resulting solution was poured into 500 ml water and acidified with dilute HCl. Yellow precipitate obtained was filtered and dried. Product was recrystallized form THF/hexane mixture. Yield: 33%. Quantum Yield: (1.8 relative to 3HF in methyl cyclohexane), Extinction coefficient: εmax (M-1 cm-1)=36000. λmax (abs)=355 nm and λmax (em )=550 nm.

Provenance & Evidence