May 1998
SYNLETT
535
Oxidative 1,2-Aryl Migration of Alkyl Aryl Ketones
Regeneration and Reuse of Poly[styrene(iodoso diacetate)] from
Recovered Poly(iodostyrene)
Tamura et al have reported that (diacetoxyiodo)benzene promotes the
After these reactions, poly(iodostyrene), to which poly[styrene(iodoso
diacetate)] was converted, was recovered by simple filtration in over
80% yield. The recovered poly(iodostyrene) was then dissolved in
chloroform at 60°C and precipitated by the addition of methanol. Its
elemental analysis showed that the recovered poly(iodostyrene)
maintains the same number of iodine atoms as the initially prepared
poly(iodostyrene). The recovered poly(iodostyrene) was oxidized to
poly[styrene(iodoso diacetate)] with peracetic acid, and its composition
was assayed again both by iodometry and by elemental analysis. Here,
the regeneration of poly[styrene(iodoso diacetate)] was successful. The
same iodination of aromatic compounds and 1,2-aryl migration of
ketone with regenerated poly[styrene(iodoso diacetate)] gave the
corresponding products in good yields, again.
1
,2-aryl migration of propiophenones to methyl 2-arylpropanoates,
acetophenones to methyl arylacetates, and 3-aroylpropionic acids to
dimethyl 2-arylsuccinates,9) which are important synthetic
intermediates of indan-1-carboxylic acids possessing anti-inflammatory
activity. Singh has also reported the 1,2-aryl migration of
acetophenones
to
α-methoxyarylacetates
with
(diacetoxy-
1
1)
1
0)
iodo)benzene.
Here, these reactions were carried out with
poly[styrene(iodoso diacetate)] instead of (diacetoxyiodo)benzene. The
reactivity of poly[styrene(iodoso diacetate)] was compared with that of
(
diacetoxyiodo)benzene under the same conditions, and the results are
8
)
shown in Table 2.
In conclusion, poly[styrene(iodoso diacetate)] has good reactivity in
these ionic reactions such as iodination of aromatic compounds and
oxidative 1,2-aryl migration of alkyl aryl ketones. After the reactions
with poly[styrene(iodoso diacetate)], poly(iodostyrene), to which
poly[stylene(iodoso diacetate)] was converted, can be recovered by
simple filtration in good yield and the poly[styrene(iodoso diacetate)]
can be regenerated and reused.
Acknowledgement: Financial support from a Grant-in-Aid (08554031)
for Developmental Scientific Research from the Ministry of Education,
Science, and Culture of Japan is gratefully acknowledged (H.T.).
References and Notes
(
1) Varvoglis, A. Synthesis, 1984, 709; Umemoto, T. Yuki Gosei
Kagaku Kyokaishi, 1983, 41, 251; Ochiai, M.; Nagao, Y. Yuki
Gosei Kagaku Kyokaishi, 1986, 44, 660; Moriarty, R. M.;Vaid, R.
K. Synthesis, 1990, 431; Moriarty, R. M. Vaid, R. K.; Koser, G. F.
Synlett, 1990, 365; Kitamura, T.; Yuki Gosei Kagaku Kyokaishi,
1
995, 53, 893; Muraki, T.; Togo, H.; Yokoyama, M. Rev.
Heteroatom Chemistry, 1997, 17, 213: Zhdankin, V. V. Rev.
Heteroatom Chemistry, 1997, 17, 133; Togo, H.; Hoshina, Y.;
Nogami, G.; Yokoyama, M. Yuki Gosei Kagaku Kyokaishi, 1997,
5
5, 90; Varvoglis, A. Tetrahedron, 1997, 53, 1179; Stang, P. J.;
Zhdankin, V. V. Chem. Rev., 1996, 96, 1123.
(
(
2) Yamada, Y.; Okawara, M. Makromol. Chem., 1972, 152, 153.
3) Hallensleben, M. L. Angew. Makromol. Chem., 1972, 27, 223;
preparation of poly[styrene(iodoso difluoride)] and its synthetic
use: Zupan, M.; Pollak, A. J. Chem. Soc., Chem. Commun., 1975,
7
15.
(
4) Iodination of polystyrene: A mixture of 16g of polystyrene, 16g of
iodine, 6g of iodine pentoxide, 40 ml of carbon tetrachloride, and
3
9
0 ml of 50% sulfuric acid in 200 ml of nitrobenzene was kept at
0°C for 40 h. After the reaction, the reaction mixture was diluted
with 100 ml of chloroform and then the precipitation occurred by
the addition of methanol (1500 ml). The precipitates were
collected by filtration. Elemental analysis showed C, 44.20%; H,
3
.24%; I, 52.07%. This result indicates that 88% of the phenyl
ring in polystyrene was iodinated. Preparation of
Poly[styrene(iodoso diacetate)]: Hydrogen peroxide (30%, 40 ml)
was added dropwise to acetic anhydride solution (145 ml) at 0°C.
The solution was slowly warmed to room temperature, and stirred
overnight. To this solution, poly(iodostyrene) (8g) was added.
Then, the solution was kept at 40°C overnight. At the end of the
reaction, ether was added to precipitate and the product was
Thus, 1,2-aryl migration of propiophenones and 3-benzoylpropionic
acid with poly[styrene(iodoso diacetate)] successfully occurred to give
the products in good yields. Therefore, poly[styrene(iodoso diacetate)]
is very useful for the oxidative 1,2-aryl migration of alkyl aryl ketones.