Facile regeneration of carbonyl compounds from oximes using poly[4-vinyl-N,N-dichlorobenzenesulfonamide]

Article abstract of DOI:10.1016/S0040-4039(02)00344-1

Oximes of aldehydes and ketones are oxidized to the corresponding carbonyl compounds in good yields under mild conditions by poly[4-vinyl-N,N-dichlorobenzenesulfonamide].

Full text of DOI:10.1016/S0040-4039(02)00344-1

TETRAHEDRON
LETTERS
Pergamon
Tetrahedron Letters 43 (2002) 3073–3074
Facile regeneration of carbonyl compounds from oximes using
poly[4-vinyl-N,N-dichlorobenzenesulfonamide]
Ardeshir Khazaei* and Ramin Ghorbani Vaghei
Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan, Iran
Received 23 November 2001; revised 4 February 2002; accepted 15 February 2002
Abstract—Oximes of aldehydes and ketones are oxidized to the corresponding carbonyl compounds in good yields under mild
conditions by poly[4-vinyl-N,N-dichlorobenzenesulfonamide]. © 2002 Elsevier Science Ltd. All rights reserved.
Regeneration of carbonyl compounds from oximes is
an important reaction and has assumed added impor-
tance not least because such derivatives of carbonyl
compounds can serve as protecting groups for alde-
Herein, we now report a convenient method for the
deoximation of ketone and aldehyde oximes to their
corresponding carbonyl compounds using a new
reagent 5 that was prepared from sodium p-styrenesul-
fonate 1 (Scheme 1). The recovery of sulfonamide 4 in
comparison to that previously reported by us is easier
and we also synthesized some other aliphatic com-
pounds with this polymeric reagent in high yields.
1–7
hydes and ketones in organic synthesis.
There has
therefore been considerable interest in the development
of novel techniques for the conversion of oximes back
into carbonyl compounds, which work under mild
conditions.
The first step of this work involved the preparation of
the polymeric reagent. Poly[4-vinyl-N,N-dichlorobenz-
enesulfonamide] 5 was prepared by the reaction of 1
We have previously reported a convenient method for
the deoximation of ketone and aldehyde oximes to their
8
corresponding carbonyl compounds with N,N%-dibro-
9
with PCl and ammonia, polymerization with AIBN,
5
mo-N,N%-1,2-ethanediylbis(p-toluenesulfonamide).
and then chlorination with Cl2(g) to yield the corre-
sponding chlorinated poly[4-vinyl-N,N-dichlorobenz-
enesulfonamide] in excellent yield as a semi-solid, which
1
was identified by H NMR and IR spectroscopy. Iodo-
metric titration was used to determine the amount of
chlorine. This new material proved to be a very power-
ful chlorinating agent, and was found to be easily
recovered, regenerated and reused (Scheme 1). The
second step is the reaction between the polymeric
reagent and oximes in CCl4.
The reaction of oximes 6 with reagent 5 in CCl4
afforded carbonyl compounds 7 without the formation
of side products (Scheme 2).
Scheme 1.
*
Corresponding author. Fax: (+98) 811 8272404; e-mail:
a-khazaei@basu.ac.ir
Scheme 2.
0
040-4039/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0040-4039(02)00344-1

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074
A. Khazaei, R. G. Vaghei / Tetrahedron Letters 43 (2002) 3073–3074
Table 1. Deoximation with poly[4-vinyl-N,N-dichlorobenzenesulfonamide]
Entry
R1
R2
Producta
Reaction times (h)
Yield (%)
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
CH3
CH3
CH3
CH3
C H
p-ClC H
p-MeOC H
p-BrC H
Acetophenone
3
5
3
3
5
1
3
2
3
2
3
5
5
5
3
4
92
91
95
94
92
91
84
90
90
96
92
91
90
92
93
92
6
5
p-Chloroacetophenone
p-Methoxyacetophenone
p-Bromoacetophenone
Benzophenone
p-Chlorobenzophenone
Benzaldehyde
p-Chlorobenzaldehyde
p-Methylbenzaldehyde
o-Methoxybenzaldehyde
Benzoin
Butyraldehyde
Heptaldehyde
Isobutyl methyl ketone
Cinnamaldehyde
2,3-Butanedione
6
5
6
5
6
5
5
5
C H
C H
6
5
5
6 5
C H
p-ClC H
6
6
H
H
H
H
C H
6
5
p-ClC H
p-MeC H
o-MeOC H
6
6
5
1
1
1
1
1
1
1
6 5
C H
C H CH(OH)
6
5
6
5
H
H
CH3
H
CH3
C H
3
7
C H
6
13
9
C H
4
C C H
6
2
2
CH CO
3
a
Products were characterized by their physical properties, comparison with authentic samples and IR spectra.
The results of the conversion of various ketoximes and
aldoximes to ketones and aldehydes are presented in
Table 1.
(5 mmol), carbon tetrachloride (15 ml) and poly[4-
vinyl-N,N-dichlorobenzenesulfonamide] 5 was refluxed
at 40°C for the specific time (Table 1). After completion
of the reaction, water (5 ml) was added to hydrolyze the
intermediate, and the insoluble polymer 4 was removed
by filtration and washed with carbon tetrachloride (10
ml). Removal of the solvent under reduced pressure
gave the crude product. Solid products were recrystal-
lized from diethyl ether, oily products being dissolved
in ether and the ether solution washed, dried and
concentrated.
The products of the reaction with 5 were isolated
simply by filtering off 4 and evaporating the solvent
from the filtrate. The method has advantage in terms of
yields, simplicity of reaction conditions, short reaction
times and no side products. The recovered starting
polymer 4 was chlorinated and used many times with-
out any reduction in its efficiency.
Commercial sodium p-styrenesulfonate (Fluka, A.G.,
Switzerland) was used as received. p-Styrene sulfon-
amide and poly(p-styrene sulfonamide) were prepared
on 30 g scale from p-sodiumstyrene sulfonate, PCl5,
ammonia and AIBN according to the published
References
1. Bandgar, B. P.; Lalita, B. K.; Thote, J. L. Synth. Com-
mun. 1997, 27, 1149–1152.
2. (a) Donaruma, L. G.; Heldt, W. Z. Org. React. 1960, 11,
1
0
procedure.
1
; (b) Bosch, A. L.; Cruz, P.; Diez-Barra, E.; Loupy, I.;
Procedure for the preparation of poly[4-vinyl-N,N-
dichlorobenzenesulfonamide]. A sample of white finely
divided powdered poly[4-vinylbenzenesulfonamide] (8.0
g) was dissolved in dry THF (50 ml). Cl2(g) was bubbled
through the system for 30 min under ice-cooling to
chlorinate the polymeric reagent. The color of the
solution did not change. The mixture was refluxed for 2
h, until a dark brown color was produced. The solvent
was evaporated, and the residue freed from the last
traces of solvent in vacuum, to give the product (18.5
g). The compound was identified by NMR, IR, and
molecular weight determination (functional groups
titration). The mole number of N-bound chlorine was
Langa, F. Synlett 1995, 1259–1260.
3. Barry, R. H.; Hartung, W. H. J. Org. Chem. 1947, 12,
460–468.
4. Touster, O. Org. React. 1953, 7, 327–377.
5. Hartung, W. H.; Crossley, F. Org. Synth. Coll. 1943, 2,
363–364.
6. Barton, D. H. R.; Beaton, J. M.; Geller, L. E.; Pechet, M.
M. J. Am. Chem. Soc. 1961, 83, 4076–4083.
7. Barton, D. H. R.; Beaton, J. M. J. Am. Chem. Soc. 1961,
83, 4083–4089.
8. Khazaei, A.; Vaghei, R. G.; Tajbakhsh, M. Tetrahedron
Lett. 2001, 42, 5099–5100.
9. Khazaei, A.; Shirdarreh, A. Synth. Commun. 1999, 29,
4079–4085.
1
1
determined by iodometric titration.
10. Yoda, N. J. Polym. Sci., Part A 1965, 3, 2229–2236.
General procedure for deoximation with poly[4-vinyl-
N,N-dichloro benzenesulfonamide]. A mixture of oxime
11. Banks, R. E.; Burling, E. D. J. Chem. Soc. 1965, 6077–
6083.