Hydrochloric Acid → Cinnamoylbenzene

HRID 742088Notes

Reaction equation

HRID 742088 reaction equation
O[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8](=[O:10])[CH3:9].[OH-].[Na+].CO.Cl>O>[C:3]1([CH:8]=[CH:9][C:8]([C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][CH:2]=2)=[O:10])[CH:4]=[CH:5][CH:6]=[CH:7][CH:2]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 887MethanolHCID 83752'-HydroxyacetophenoneHCID 14798Sodium Hydroxide

Product 1

HCID 7189Cinnamoylbenzene

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of 1.02 g (7.49 mmol) of 2'-hydroxyacetophenone, 0.49 g (3.65 mmol) of 1,4-benzodicarboxaldehyde, 1.5 g NaOH (in 5 mL of water) and 30 mL MeOH was stirred for 21 hours before the solution was poured into 200 mL water. The resulting mixture was neutralized with dilute HCl and the yellow precipitate was collected by filtration. Recrystalization from MeOH gave a pure intermediate chalcone product. Further oxidation of the above chalcone was carried out with excess H2O2 (30%) in basic (NaOH aq.) MeOH solution for 20 hours. This solution was poured into water, and neutralized with dilute HCl. The resulting light yellow precipitate was collected by filtration and the pure desired product was obtained by recrystallization from MeOH with 22% overall yield. MP: 385°-387° C. Quantum yield (relative to 3-hydroxyflavone in CH2Cl2) 1.2. Extinction coefficient εmax (M-1 cm-1) 36,000. λmax (abs)=380 nm and λmax (em)=560 nm.

Workup

  1. filtrationthe yellow precipitate was collected by filtration
  2. customRecrystalization from MeOH

Sources & evidence

ORD record
ord-ce506b40bd5a4d81b942f72460699630
Source dataset
uspto-grants-1996_09
Patent number
US05552551

Reaction notes

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