Hydrochloric Acid → Cinnamoylbenzene

HRID 742087Notes

Reaction equation

HRID 742087 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 2.50 g (19.0 mmol) of 2'-hydroxyacetophenone, 2.42 g (18.6 mmol) of phenylpropargyladehyde, 3.44 g NaOH (in 9 mL of water) and 50 mL MeOH was stirred for 16 hours before the solution was poured into 500 mL water. The resulting mixture was neutralized with dilute HCl and extracted with CH2Cl2. The solvent was removed from the organic phase. Column separation with CH2Cl2 -petroleum ether (1:1) 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 18 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 2% overall yield. MP: 153°-154° C. Quantum yield (relative to 3-hydroxyflavone in CH2Cl2) 1.6. Extinction coefficient εmax (M-1 cm-1) 21,000. λmax (abs)=372 nm and λmax (em)=540 nm.

Workup

  1. extractionextracted with CH2Cl2
  2. customThe solvent was removed from the organic phase
  3. customColumn separation with CH2Cl2 -petroleum ether (1:1)

Sources & evidence

ORD record
ord-d6a3c4fce3fb4a769415766084598a3b
Source dataset
uspto-grants-1996_09
Patent number
US05552551

Reaction notes

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