The application of N,N′-dibromo-N,N′-1,2-ethanediylbis (p-toluenesulphonamide) as a powerful reagent for deoximation of various oximes

Article abstract of DOI:10.1016/S0040-4039(01)00897-8

N,N′-Dibromo-N,N′-1,2-ethanediylbis (p-toluenesulphonamide) [BNBTS] 2 was reacted with oximes and converts them to their corresponding carbonyl compounds in good yields under mild conditions.

Full text of DOI:10.1016/S0040-4039(01)00897-8

TETRAHEDRON
LETTERS
Pergamon
Tetrahedron Letters 42 (2001) 5099–5100
The application of N,N%-dibromo-N,N%-1,2-ethanediylbis
(p-toluenesulphonamide) as a powerful reagent for deoximation
of various oximes
Ardeshir Khazaei,a,* Ramin Ghorbani Vagheia and Mahmoud Tajbakhshb
aDepartment of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan, Iran
bDepartment of Chemistry, Faculty of Science, Mazandaran University, Babolsar, Iran
Received 19 March 2001; revised 18 April 2001; accepted 24 May 2001
Abstract—N,N%-Dibromo-N,N%-1,2-ethanediylbis (p-toluenesulphonamide) [BNBTS] 2 was reacted with oximes and converts them
to their corresponding carbonyl compounds in good yields under mild conditions. © 2001 Elsevier Science Ltd. All rights
reserved.
Protection of carbonyl compounds as oximes is of great
interest to synthetic chemists, as they are readily pre-
pared and highly stable compounds.1 Oximes are exten-
sively used for characterization of carbonyl compounds
and in the preparation of amides via the Beckman
rearrangement.2 Since oximes can be prepared from
non-carbonyl compounds,3–7 the regeneration of car-
bonyl compounds from oximes provides an alternative
method for preparation of aldehydes and ketones.
Some of the reagents reported for deoximation8–10 are
often hazardous or very toxic, expensive, or not readily
available, they need to be freshly prepared or the
reactions require drastic conditions, long reaction times
and tedious work-up. Thus, a milder, selective, non-
hazardous and inexpensive reagent is still in demand.
the solvent from the filtrate. The method has advantage
in terms of yields, simplicity of the reaction conditions,
shorter reaction times and no side products. The recov-
ered starting material (1), was rebrominated and used
many times without reducing the yield.
The oximes were prepared by a standard procedure.
The purity of the compounds was checked by TLC. A
mixture of oxime (5 mmol), carbon tetrachloride (15
ml) and BNBTS (5 mmol) was stirred at room tempera-
ture for the specified time (Table 1). The reaction was
monitored by TLC. After completion of the reaction,
We now report a convenient method for the deoxima-
tion of ketone and aldehyde oximes to their corre-
sponding carbonyl compounds using a new reagent
(BNBTS)
2
that was prepared from N,N%-1,2-
ethanediylbis (p-toluenesulphonamide)[1] (Fig. 1).11
The reaction of oximes (3) with BNBTS in CCl4
afforded carbonyl compounds (4) without side products
(Scheme 1).
Figure 1.
The results of the conversion of various ketoximes and
aldoximes to ketones and aldehydes are presented in
Table 1. The products of the reaction with BNBTS
were isolated simply by filtering off (1) and evaporating
* Corresponding author. Fax: (+98) 811 8272404; e-mail: a-khazaei
@basu.ac.ir
Scheme 1.
0040-4039/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4039(01)00897-8

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A. Khazaei et al. / Tetrahedron Letters 42 (2001) 5099–5100
Table 1. Deoximation with BNBTS
Entry
Yield (%)
R1
R2
Producta
Reaction times (h)
1
2
3
4
5
6
7
8
95
94
97
96
94
94
85
91
88
95
90
CH3
CH3
CH3
CH3
C6H5
C6H5
H
H
H
H
C6H5
C6H5
Acetophenone
2
4
2
2
4
0.5
2
1
2
p-ClC6H5
p-MeOC6H5
p-BrC6H5
C6H5
p-ClC6H5
C6H5
p-ClC6H5
p-MeC6H5
o-MeOC6H5
C6H5CH(OH)
p-Chloroacetophenone
p-Methoxyacetophenone
p-Bromoacetophenone
Benzophenone
p-Chlorobenzophenone
Benzaldehyde
p-Chlorobenzaldehyde
p-Methylbenzaldehyde
o-Methoxybenzaldehyde
Benzoin
9
10
11
1
2
a Products were characterized by their physical constants, comparison with authentic samples and IR spectra.
water was added to hydrolyze the intermediate, and the
insoluble sulfonamide (1) was removed by filtration and
washed with cold carbon tetrachloride (10 ml).
Removal of the solvent under reduced pressure gave the
crude product. Solid products were recrystallized from
diethyl ether, oily products being dissolved in ether and
the ether solution washed, dried and concentrated.
460–468.
4
5
Touster, O. Org. React. 1953, 7, 327–377.
Hartung, W. H.; Cressly, F. Org. Synth. Coll. 1943, 11,
363–364.
Barton, D. H. R.; Beaton, J. M.; Geller, L. E.; Pechet, M.
M. J. Am. Chem. Soc. 1961, 83, 4076–4083.
Barton, D. H. R.; Beaton, J. M. J. Am. Chem. Soc. 1961,
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Greene, T. W.; Wuts, P. G. M. Protective Groups in
Organic Synthesis; John Wiley and Sons: New York,
1991.
6
7
8
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