Org. Synth. 1928, 8, 36
Submitted by Roger Adams, J. W. Kern, and R. L. Shriner.
Checked by Henry Gilman and S. A. Harris.
A solution of 20.8 g. (0.1 mole) of benzalacetophenone (p. 78) (Note 1)
in 150 cc. of c.p. ethyl acetate (Note 2)
is placed in the reaction bottle of the catalytic reduction apparatus (p. 61)
, and 0.2 g. of platinum oxide
catalyst (p. 463)
is added. The apparatus is evacuated, then filled with hydrogen
, and the mixture shaken with hydrogen
until 0.1 mole has been absorbed. The time required is usually about fifteen to twenty-five minutes (Note 3)
. The platinum
is filtered off and the solvent removed from the filtrate by distillation. The benzylacetophenone
is recrystallized from about 25 cc. of alcohol
and melts at 72–73°
. The yield is 17–20 g.
per cent of the theoretical amount).
should be freshly recrystallized from alcohol
just before using and should melt at 57°
Owing to the comparatively slight solubility of benzalacetophenone
, ethyl acetate
is used as a solvent during the reduction.
If 0.1 g. of catalyst is used the reduction requires about three hours; an increase in catalyst to 0.5 g. causes the reduction to take place in three or four minutes. The exact time depends to a considerable extent on the grade of benzalacetophenone
used and it is not certain that the purest will necessarily be reduced in the shortest time.
can be prepared by the reduction of benzalacetophenone
with zinc and acetic acid1
and catalytically with palladium and hydrogen
by the oxidation of the corresponding carbinol with chromic acid
and by the hydrolysis of ethyl benzylbenzoylacetate
This preparation is referenced from:
Chemical Abstracts Nomenclature (Collective Index Number);
acetic acid (64-19-7)
ethyl acetate (141-78-6)
Propiophenone, β-phenyl- (1083-30-3)
chromic acid (7738-94-5)
Copyright © 1921-, Organic Syntheses, Inc. All Rights Reserved