Efficient oxidation of alcohols to carbonyl compounds by N,N-dichloro-4-methylbenzenesulfonamide under mild conditions

Article abstract of DOI:10.1002/jccs.200700065

A number of aldehydes and ketones were prepared by oxidation of alcohol by N,N-dichloro-4-methylbenzenesulfonamide under mild and neutral conditions in good to high yield in dichloromethane at room temperature.

Full text of DOI:10.1002/jccs.200700065

Journal of the Chinese Chemical Society, 2007, 54, 465-468
465
Efficient Oxidation of Alcohols to Carbonyl Compounds by
N,N-Dichloro-4-methylbenzenesulfonamide under Mild Conditions
Ardeshir Khazaei,a* Ayeh Raiatzadeha and Amin Rostamib
aDepartment of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan, 6517838683, Iran
bDepartment of Chemistry, Faculty of Science, Kurdistan University, Sanandaj, Iran
A number of aldehydes and ketones were prepared by oxidation of alcohol by N,N-dichloro-4-
methylbenzenesulfonamide under mild and neutral conditions in good to high yield in dichloromethane at
room temperature.
Keywords: Alcohol; Oxidation; N,N-Dichloro-4-methylbenzenesulfonamide; Aldehydes; Ke-
tones.
INTRODUCTION
The oxidation of alcohol to carbonyl compounds is a
carbonyl compounds in the presence of N,N-dichloro-4-
methylbenzenesulfonamide and pyridine (0.5 mL) in di-
chloromethane at room temperature. (Scheme I).
fundamental synthetic transformation, and a wide variety
of reagents have been developed for this important reac-
tion.1-3 The methods that have been used extensively in oxi-
dation of alcohol include the PCC catalyzed oxidation with
RESULTS AND DISCUSSION
periodic acid,4 silica gel supported InBr3 and InCl3 , etc.6-13
5
In this research the effect of pyridine as a base on the
reaction rate was investigated. We found that the rate of ox-
idation reaction was increased when 4-bromobenzyl alco-
hol was oxidized to the corresponding carbonyl compound
with N,N-dichloro-4-methylbenzenesulfonamide in the
presence of pyridine (Scheme II).
During the course of our systematic study on oxida-
tion and halogenation of organic compounds with N-halo
reagents,14-21 we have found that N,N-dichloro-4-methyl-
benzenesulfonamide22 is an inexpensive, easily obtained,
moisture insensitive, low toxic and low corrosive reagent.
We now report a convenient method for the oxidation of al-
cohols using N,N-dichloro-4-methylbenzenesulfonamide
as oxidizing reagent, which overcomes the disadvantages
associated with oxidative methods developed so far.
However, 1.5 mmol of oxidant and 0.5 mL of pyridine
in CH2Cl2 at room temperature were optimal conditions for
the desired oxidation of alcohols (Table 1).
As shown in Table 1, primary benzylic alcohols with
electron releasing and electron withdrawing substituent
Various alcohols were converted to corresponding
Scheme I
O
OH
H3C
SO2NCl2
,
rt
Py
CH2Cl2 ,
R1
R2
R1
R2
R1: H, aryl, alkyl
R2: aryl, alkyl
* Corresponding author. E-mail: a_rostami372@yahoo.com

466 J. Chin. Chem. Soc., Vol. 54, No. 2, 2007
Khazaei et al.
Scheme II
H3C
SO2NCl2
CH2OH
Br
Br
CHO
,
rt
CH2Cl2
18 h
H3C
SO2NCl2
Br
Br
CHO
CH2OH
,
,
CH2Cl2 Py
rt
3 h
Table 1. Oxidation of alcohols to carbonyl compounds by N,N-dichloro-4-methylbenzenesulfonamide in dichloromethane at room
temperature
Time
(hrs)
Yielda
(%)
M.p.
Lit.23-26 M.p.
Entry
1
Substrate
CH2OH
Product
CHO
(°C)
(°C)
3.5
3
90
96
95
234-236
232-233
110-111
237
233
111b
2
3
CH2OH
H3C
Br
H3C
Br
CHO
CHO
CH2OH
3
Cl
Cl
CH2OH
Cl
CHO
4
5
87
70-72
72c
Cl
H3CO
NO2
5
6
2.5
18
92
90
251-253
317-319
253
320
CH2OH
CHO
H3CO
NO2
CH2OH
CHO
7
8
9
PhCH(OH)Ph
4
7
5
Ph2CO
86
88
95
235-237
245-248
104-106
238
248-249
106
CH3CH(OH)Ph
CH3(CH2)6CH2OH
CH3C(O)Ph
CH3(CH2)6CHO
10
4
90
120-121
120
CH2CHO
CH2CH2OH
11
12
CH3CH(OH)(CH2)4CH3
C2H5CH(OH)C2H5
5
CH3C(O)(CH2)4CH3
C2H5C(O)C2H5
96
95
87-89
89
4.5
154-156
156
13
OH
OH
4
O
85
158-160
161
O
14
8
80
131-132
132b
a Products were characterized by melting points of the corresponding of 2,4-dinitrophenylhydrazone derivatives and their IR and 1H
NMR spectra. b Melting points of semicarbazone derivatives. c Melting point of 2,4-dichlorobenzaldehyde.

Oxidation of Alcohols to Carbonyl Compounds
J. Chin. Chem. Soc., Vol. 54, No. 2, 2007 467
Scheme III
O
S
R2
C
O
S
H
Cl
H
2
2
R1
N
CH3
+
R1
OH
+
H3C
N
C
O
Cl
Cl
H
O
H
O
R2
N
H
R1
R2
2
2
R1
C
O
Cl
O
R2
EXPERIMENTAL SECTION
General Procedure for Oxidation
were oxidized, and the corresponding carbonyl compounds
were obtained in good to excellent yields (entries 1-6).
Benzhydrol and 1-phenyl ethanol, as two model compounds
for secondary benzylic alcohol, were oxidized by this re-
agent (Table 1, entries 7, 8). Linear and cyclic saturated pri-
mary and secondary compounds were also oxidized to car-
bonyl compounds (Table 1, entries 9-14).
A solution of alcohol (1.0 mmol), N,N-dichloro-4-
methylbenzenesulfonamide (1.5 mmol), and pyridine (0.5
mL) in CH2Cl2 (5 mL) was stirred at room temperature for
the time indicated in Table 1. The reaction was monitored
by TLC. After completion of the reaction, HCl (10% 10
mL) was added to the reaction mixture. The organic layer
was separated and dried over anhydrous Na2SO4. After-
wards, the solvent was evaporated; n-hexane (20 mL) was
added to the residual, filtered and washed with n-hexane.
Evaporation of the n-hexane gave the corresponding car-
bonyl compounds in 80-96% yields. Their 2,4-dinitrophen-
ylhydrazone derivatives were recrystallized from ethanol.
The actual role of N,N-dichloro-4-methylbenzenesul-
fonamide is not clear, on the basis of a previously reported
mechanism.27 It has been suggested that the primary or sec-
ondary alcohol forms a hypochlorite which readily loses
hydrogen chloride to form the carbonyl product (Scheme
III).
CONCLUSIONS
ACKNOWLEDGEMENT
In conclusion, the advantages of this method are as
follows:
We are thankful to the Bu-Ali Sina University Re-
search Councils for partial support of this work.
1. The N,N-dichloro-4-methylbenzenesulfonamide is
inexpensive, moisture insensitive, non-metallic, low toxic
and corrosive, air and water stable and no special efforts are
required for preparation. Also it was converted to 4-meth-
ylbenzenesulfonamide which can be isolated, chlorinated
and reused as oxidizing reagent.
Received March 28, 2006.
2. There is no need to use a co-reagent such as a heavy
metal, and the reaction occurs at room temperature; there-
fore, it is suitable economically and environmentally.
3. The primary alcohols were oxidized to the corre-
sponding aldehydes without over-oxidation of aldehydes,
and the benzilic alcohols were oxidized to their corre-
sponding carbonyl compound without chlorination of aro-
matic ring; these observations demonstrate the chemo-
selectivity of this method.
REFERENCES
1. Hudlicky, M. Oxidations in Organic Chemistry; American
Chemical Society: Washington, DC, 1990 and references
therein.
2. Trost, B. M.; Fleming, I. Comprehensive Organic Synthesis;
Eds., Pergamon Press: Oxford, 1991, 7, 305 and references
therein.
3. Luzzio, F. A. Org. React. 1998, 53, 1.
4. Hunsen, M. Tetrahedron Lett. 2005, 46, 1651.

468 J. Chin. Chem. Soc., Vol. 54, No. 2, 2007
Khazaei et al.
5. Ahmad, N.; Ali, H.; Van Lier, J. E. Tetrahedron Lett. 2005,
46, 253.
17. Khazaei, A.; Rostami, A.; Tanbakochian, Z.; Zinati, Z.
Catal. Commun. 2006, 7, 214.
6. Mori, K.; Hara, T.; Mizugaki, T.; Ebitani, K.; Kaneda, K. J.
Am. Chem. Soc. 2004, 126, 10657.
18. Khazaei, A.; Rostami, A.; Manesh, A. A. J. Chin. Chem.
Soc. 2006, 53, 43.
7. Mallat, T.; Baiker, A. Chem. Rev. 2004, 104, 3037.
8. Rafelt, J. S.; Clark, J. H. Cata. Today. 2000, 57, 33.
9. Manyar, H. G.; Chaure, G. S.; Kumar, A. J. Mol. Cata.
A-Chem. 2006, 243, 244.
19. Khazaei, A.; Zolfigol, M. A.; Manesh, A. A. J. Chin. Chem.
Soc. 2005, 52, 515.
20. Khazaei, A.; Manesh, A. A. J. Chin. Chem. Soc. 2005, 52,
1017.
10. Kashiwagi, Y.; Ikezoe, H.; Ono, T. Synlett 2006, 69.
11. Karimi, B.; Zamani, A.; Clark, J. H. Organometallics 2005,
24, 4695.
21. Khazaei, A.; Manesh, A. A.; Safi, V. R. J. Chin. Chem. Soc.
2005, 52, 559.
22. Akiyoshi, S.; Okuno, K. J. Am. Chem. Soc. 1954, 76, 693.
23. Rappoport, Z. Handbook of Table for Organic Compound
Identification; Third edition, 1976.
12. Mirjalili, B. F.; Zolfigol, M. A.; Bamoniri, A.; Zarei, A. J.
Chin. Chem. Soc. 2004, 51, 509.
13. Tzuen-Yeuan, L.; Chih-Ming, C.; Han-Wei, Z. J. Chin.
Chem. Soc. 1995, 42, 43.
24. Fluka. Merk, BDH and Aldrich Catalogues, (chemicals) and
Biochemicals, 1994.
14. Khazaei, A.; Aminimanesh, A.; Rostami, A. J. Chem. Res.
2005, 391.
25. Bukingham, J. Dictionary of Organic Compounds; (5th) Ed.,
Champan and Hall, 1682.
15. Khazaei, A.; Zolfigol, M. A.; Rostami, A. Synthesis 2004,
2959.
26. Vogel, A. Textbook of Practical Organic Chemistry; (4th)
Ed., Longman: New York, 1978; p 1202.
27. Filler, R. Chem. Rev. 1963, 63, 21.
16. Khazaei, A.; Rostami, A.; Tanbakochian, Z.; Zinati, Z. J.
Braz. Chem. Soc. 2006, 17, 206.