Chemistry Reference
In-Depth Information
O
O
EPA10
+
C
12
- C
14
ALKENE
C
12
- C
14
ALKYL
50-70
o
C/2h
Conversion = 100%
Yield >90%
Selectivity = 85% Monoalkyl
<1% Oligomers
Scheme 13.29
AlCl
3
+
90
o
C / 1h
Scheme 13.30
-
Isobutyraldehyde
O
O
O
2
/ DCM / 30ºC / 5h
O
O
O
Co
Conversion = 97%
Selectivity = 86% Epoxide
14% Heavies
O
Si
O
-
Scheme 13.32
CH
3
COOH
Scheme 13.31
90-110
o
C
method of preparation of epoxides involves the
use of highly toxic and corrosive peracids, e.g.
m
-
chloroperbenzoic acid [61]. Unfortunately, owing to
the sensitivity of the expoxide function to nucle-
ophilic attack, the benzoic acid liberated from the
formation of the epoxide attacks the molecule, re-
sulting in the production of large volumes of un-
wanted by-products.
Envirocat EPCS is not only an efficient catalyst for
epoxidation but it is also highly selective, resulting
in high yields of the epoxide. The reaction is per-
formed under an atmosphere of O
2
at near-ambient
temperatures. The oxidation is achieved using a sac-
rificial aldehyde (see Scheme 13.32). Surprisingly,
the corresponding carboxylic acid formed only has a
limited effect on by-product formation [62].
O
2
/ 24h
H
H
Yield = 70%
Scheme 13.33
to benzoic acid at atmospheric pressure at the reflux
temperature of toluene (see Scheme 13.33).
Further work has shown that it may be possible to
use the same system to achieve a Baeyer-Villiger oxi-
dation, replacing organic peracids with O
2
. It is
hoped that if this project comes to a successful con-
clusion, customers will be informed of this advance
in oxidation chemistry some time during 2001.
10 Future Envirocats
The R&D team at CCL is still very active in the design
and development of new catalysts. A new oxidation
catalyst and reaction conditions currently are being
developed that are showing some very promising
results. So far, toluene has been oxidised successfully
11 Conclusions
It is evident that national and international legisla-
tion and public pressure and opinion will continue
