Overview
- Chalcone is the common name for E-1,3-Diphenyl-2-propen-1-one.
You will prepare a monofluoro derivative of
chalcone (compounds 1 - 8 below)
using a crossed aldol condensation between a
substituted benzaldehyde and a substituted
acetophenone. The relatively green, solvent-free
method detailed in the paper by Palleros2
will be used.
Group
Compound
R
R'
Chalcone
H
H
A♥
1
4-F
H
K♥
2
4-F
3,4
-O-CH2-O-
Q♥
3
4-F
4-NO2
J♥
4
2,4-dichloro
4-F
9♥
5
3-NO2
4-F
8♥
6
3,4
-O-CH2-O-
4-F
5♥
7
4-Me
4-F
3♥
8
4-NO2
4-F
Procedures
We will use
the procedure from reference 2 and copied
below:
"In a
typical reaction, 5 mmol of the
benzaldehyde and 5 mmol of the
acetophenone were added to a 3-inch
porcelain mortar, 200 mg of solid NaOH
(about a pellet) was added and the
mixture ground with a pestle for about
5-10 minutes. Grinding was continued
until the mixture solidified and the
solid broke up in small particles.
Distilled water (10 mL) was added and
the product mixed well with the water,
with the pestle and a spatula used to
dislodge the solid from the mortar's
wall. The suspension was vacuum filtered
using a Buchner funnel. Mortar and
pestle were rinsed with 5 mL of water
and the rinses collected on the same
filter. The product was washed on the
filter with an additional 5-mL aliquot
of water and it was allowed to air-dry
on the filter."
Recrystallization.
Carry out small-scale tests (Mohrig, pp
188-189) to determine the best
recrystallization solvent from among 95%
ethanol, toluene-ethanol, ethanol-water, or
methanol and then recrystallize the remainder
of the product from this solvent.
Characterization.
Obtain the mp as well as 1H
NMR, 13C NMR, and IR spectra of
the final product.