1070-4272/04/7706-0998 C 2004 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 77, No. 6, 2004, pp. 998!1001. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 6, 2004,
Original Russian Text Copyright + 2004 by O. Fedevich, Levush, E. Fedevich, Kit.
AND POLYMERIC MATERIALS
Role of Peroxy Compounds in Oxidation of Crotonaldehyde
with Molecular Oxygen
O. E. Fedevich, S. S. Levush, E. V. Fedevich, and Yu. V. Kit
L’vivs’ka Politekhnika National University, Lviv, Ukraine
Lviv State Agricultural University, Lviv, Ukraine
Received November 19, 2003; in final form, March 2004
Abstract-Oxidation of crotonaldehyde with molecular oxygen and the role of percrotonic acid accumu-
lating in the process were studied.
Crotonic acid (CAc) and its derivatives are used as
comonomers in production of rubbers, latexes, adhe-
sives, and plastics. Some crotonic acid esters exhibit
insecticidal or herbicidal properties.
The main synthetic route to CAc is oxidation of
crotonaldehyde (CAl). In oxidation of CAl with mo-
lecular oxygen at atmospheric [1, 2] or elevated 
pressure, peroxy compounds accumulate in concentra-
tions comparable with that of the forming CAc.
Our goal was to examine the possibility of using
peroxides accumulating in the oxidate to raise the
yield of CAc.
Pure-grade CAl was distilled before use on a labor-
atory column (10 TP, reflux ratio 2); the fraction with
bp 3753376 K was collected. Crotonaldehyde was
kept under argon at 253 K. An additional purification
was performed by steam distillation, with the collec-
tion of the azeotrope (75.7 wt % CAl, 24.3 wt %
O), from which water was frozen out at 223 K, and
CAl was dried over MgSO
and distilled on a column.
A chromatographically pure CAl was thus obtained
(bp 375 K, d
0.853 g cm
). The optimal medium
for CAl oxidation, from the viewpoint of CAc yield,
is ethyl acetate . We used ethyl acetate of analyti-
cally pure grade ; it was dried over CaCl
Qualitative and quantitative analyses were per-
formed by chemical methods , gas chromatog-
raphy, and IR spectroscopy. Chromatographic ana-
lyses were carried out on a Tsvet-100 chromato-
graph (2000 0 3-mm column; sorbent Polysorb-1,
0.130.25 mm; column and vaporizer temperatures 423
and 463 K, respectively; thermal conductivity de-
tector). In the oxidate, we determined the content of
CAl and CAc. The total content of carbonyl com-
pounds was determined by the hydroxylamine method
, and the total content of acids, by titration with
0.1 N NaOH in the presence of phenolphthalein. The
content of peroxides was determined by iodometric
titration in glacial acetic acid.
The gas3chromatographic analysis gives the total
content of crotonic and percrotonic (PCAc) acids,
because PCAc transforms into CAc in the vaporizer.
To confirm this conclusion, we performed absolute cal-
ibration with respect to CAc in the system CAc3ethyl
acetate. Percrotonic acid was prepared by oxidation of
CAc in ethyl acetate at a low temperature. For exam-
ple, in oxidation of CAl at 12oC to 15% conversion,
the content of PCAc in the sum of acids reaches 93%.
Such an oxidate gives a chromatographic peak of
CAc, whose area corresponds to the total calculated
amount of PCAc and CAc and is consistent with the
total acid content determined by chemical analysis.
In oxidation of CAl under various conditions, the
oxidate always contains PCAc and CAc (Table 1).
The PCAc : CAc ratio decreases with increasing tem-
perature, oxidation time, and partial oxygen pressure.
Peroxy compounds disappear from the oxidate upon
prolonged storage (1003150 h). The approximate
composition of the oxidate stored for 150 h at 20oC
is as follows (wt %): ethyl acetate 75.04, CAl 8.97,
CAc 12.46, propionaldehyde 0.40, propionic acid
0.50, formic acid 1.20, propenyl formate 0.60, and
1,2-epoxypropenyl formate 0.60.