An Efficient Oxidation of Acid Hydrazides to N,N′-Diacylhydrazines Using Copper(II) Acetate in Solvent-Free Conditions Under Microwave Irradiation

Article abstract of DOI:10.1081/SCC-120025183

A simple and efficient method for solvent free "dry" state transformation of acid hydrazides 1 to corresponding N,N′ -diacylhydrazines 2 using copper(II) acetate under microwave irradiation has been described. The products are obtained in good yields and excellent purities.

Full text of DOI:10.1081/SCC-120025183

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An Efficient Oxidation of Acid Hydrazides to N,N′-
Diacylhydrazines Using Copper(II) Acetate in Solvent-
Free Conditions Under Microwave Irradiation
K. Mogilaiah a , M. Prashanthi a & G. Randheer Reddy a
a Department of Chemistry , Kakatiya University , Warangal, India
Published online: 16 Aug 2006.
To cite this article: K. Mogilaiah , M. Prashanthi & G. Randheer Reddy (2003) An Efficient Oxidation of Acid Hydrazides
to N,N′-Diacylhydrazines Using Copper(II) Acetate in Solvent-Free Conditions Under Microwave Irradiation, Synthetic
Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry, 33:21, 3741-3745, DOI:
10.1081/SCC-120025183
To link to this article: http://dx.doi.org/10.1081/SCC-120025183
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SYNTHETIC COMMUNICATIONSÕ
Vol. 33, No. 21, pp. 3741–3745, 2003
An Efficient Oxidation of Acid Hydrazides to
N,N0-Diacylhydrazines Using Copper(II)
Acetate in Solvent-Free Conditions
Under Microwave Irradiation
*
K. Mogilaiah, M. Prashanthi, and G. Randheer Reddy
Department of Chemistry, Kakatiya University,
Warangal, India
ABSTRACT
A simple and efficient method for solvent free ‘‘dry’’ state transfor-
mation of acid hydrazides 1 to corresponding N,N 0-diacylhydrazines
2 using copper(II) acetate under microwave irradiation has been
described. The products are obtained in good yields and excellent
purities.
There is a growing popularity of using microwave irradiation to
carry out solventless reactions and hence become an attractive method
for chemical synthesis.[1–4] It involves neat reactants to be exposed to
microwave irradiation so as to get greater selectivity and achieve high
*Correspondence: K. Mogilaiah, Department of Chemistry, Kakatiya
University, Warangal, 506 009, India; E-mail: mogilaiah_k@yahoo.co.in.
3741
DOI: 10.1081/SCC-120025183
Copyright & 2003 by Marcel Dekker, Inc.
0039-7911 (Print); 1532-2432 (Online)
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3742
Mogilaiah, Prashanthi, and Reddy
yields within a short reaction time and with ease in experimentation.
Furthermore, the solid state reaction (or solvent-free reactions) has
many advantages: reduced pollution, low cost, simplicity in process, and
handling. Recently an informative review by Tanaka and Toda[5] clearly
points out the superiority of this solvent-free or the use of ‘‘dry’’ reaction
conditions in chemical synthesis. Diacylhydrazines are very useful
synthons for a variety of bioactive molecules. The oxidative coupling of
acid hydrazides is an important method for the formation of diacyl-
hydrazines. Several reagents are documented on the literature to effect
this conversion, however these reagents suffer from certain drawbacks
such as usage of toxic reagents like LTA, long reaction periods, low
yields of the products, use of expensive reagents, and cumbersome
work-up procedures.[6–8] Therefore, introduction of new methods and
inexpensive reagents for such oxidative dimerizations is still in demand.
Copper(II) acetate is an inexpensive and readily available oxidizing agent.
In view of this and in continuation of our interest on microwave assisted
organic transformations,[9–12] herein we report a simple and efficient
method for the conversion of acid hydrazides to N,N0-diacylhydrazines
using copper(II) acetate in solvent-free conditions under microwave
irradiation.
Treatment of the acid hydrazides 1 with copper(II) acetate without
any solvent under microwave irradiation resulted in the formation of
N,N0-diacylhydrazines 2 in very good yields (Sch. 1). The reaction is
clean and efficient. The products were formed in excellent purities in a
short reaction time. The high yield transformation did not form any
undesirable by-products. The process is environmentally benign. The
experimental procedure is very simple.
In a typical case, an equimolar amount of benzhydrazide 1a and
copper(II) acetate were mixed in a conical flask, covered with a funnel
and this neat mixture was irradiated in a microwave oven at 700 W.
Within 2.5 min the mixture was fused and this liquid on cooling
became semi-solid. After usual work-up N,N0-dibenzoylhydrazine 2a
was obtained in 82% yield.
O
H
N
O
Cu (OAc)2
MW
R
R
N
H
R
NHNH2
O
1
2
Scheme 1.

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Oxidation of Acid Hydrazides to N,N0-Diacylhydrazines
3743
The generality of this facile transformation was established by
treating other acid hydrazides 1b–j with copper(II) acetate under micro-
wave irradiation to get the corresponding N,N0-diacylhydrazines 2b–j in
high yields. The results are summarized in Table 1. Thus to the best of
our knowledge this is the first report on solid state, microwave assisted
oxidative dimerization of acid hydrazides using copper(II) acetate.
A plausible mechanism for the conversion of 1 to 2 is outlined in
Sch. 2. The intermediacy of acyldiimide 4 in the oxidative dimerization of
acid hydrazides has previously been suggested by others.[13–15]
In conclusion, we have described an efficient, rapid, and convenient
procedure for the oxidation of acid hydrazides to N,N0-diacylhydrazines
using copper(II) acetate under microwave irradiation in solvent-free
conditions. This method has the additional advantages of simple perfor-
mance, high yields, short reaction times, economic viability, easy work-up,
high purity of the products, and minimum environmental impact.
EXPERIMENTAL
Melting points were determined on Cintex melting point apparatus
and are uncorrected. IR spectra were recorded on a Perkin–Elmer
1
spectrum BX series FT-IR spectrophotometer and H NMR spectra on
a Varian Gemini 200 MHz spectrometer using Me4Si as internal
standard. Analytical TLC was performed on Merck 60F-254 silica gel
Table 1. Microwave assisted oxidation of acid hydrazides 1 to N,N0-diacyl-
hydrazines 2 using copper(II) acetate.
Reaction
time (min)
Yield
(%)
M.p.
(ꢀC)
M.p.[Ref.]
(ꢀC)
Product
Ar
2a
2b
2c
2d
2e
2f
C6H5
2.5
5
82
86
78
84
90
76
75
80
83
85
237ꢁ238
252ꢁ253
227ꢁ228
220ꢁ221
291ꢁ292
296ꢁ297
297ꢁ298
287ꢁ288
223ꢁ224
253ꢁ254
238ꢁ240[16]
253ꢁ254[17]
228ꢁ228.5[18]
219ꢁ221[7]
292[18]
4-CH3C6H4
4-CH3OC6H4
2-ClC6H4
4
6
4-ClC6H4
5
2-HOC6H4
2-NO2C6H4
4-NO2C6H4
3-C5H4N
1
298[19]
2g
2h
2i
5
298[20]
7
291[20]
4.5
4
225[20]
2j
4-C5H4N
253ꢁ255[21]

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3744
Mogilaiah, Prashanthi, and Reddy
O
O
NH
OAc
Cu
Cu (OAc)2
-AcOH
-Cu
R
NH
O
R
NHNH2
1
3
N
OAc
-AcOH
O
Cu (OAc)2
2
R
N
Cu
NH
N
-N2
-Cu
R
5
4
R CONHNH2
Scheme 2.
plates. Microwave irradiations were carried out in BPL 800 G microwave
oven.
General Procedure for the Conversion of Acid Hydrazides
1 to N,N0-Diacylhydrazines 2
A mixture of appropriate acid hydrazide 1 (0.01 mol) and copper(II)
acetate (0.01 mol) were mixed together without any solvent in a 100 mL
conical flask capped with a glass funnel and irradiated in a microwave
oven at 700 W for appropriate time (Table 1). After complete conversion
as indicated by TLC, to the reaction mixture was added water
(50 mL) and conc. HCl (2 mL). The solid separated was filtered and
recrystallized from ethanol to afford 2 (Table 1).
ACKNOWLEDGMENT
The authors are thankful to the Director, IICT, Hyderabad for
1
recording H NMR spectra.
REFERENCES
1. Caddick, S. Tetrahedron 1995, 51, 10403.
2. Bose, A.K.; Banik, B.K.; Lavlinskakia, N.; Jayaraman, M.; Monhas,
M.S. Chemtech. 1997, 27, 18.

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Oxidation of Acid Hydrazides to N,N0-Diacylhydrazines
3745
3. Loupy, A.; Petit, A.; Hamelin, J.; Texier-Boullet, F.; Jacquault, P.;
Mathe, D. Synthesis 1998, 1213.
4. Lidstrom, P.; Tierney, J.; Wathey, B.; Westman, J. Tetrahedron
2001, 57, 9225.
5. Tanaka, K.; Toda, F. Chem. Rev. 2000, 100, 1025.
6. Gladstone, W.A.F. J. Chem. Soc. 1969, 1571.
7. Imamoto, T.; Mukaiyama, T. Bull. Chem. Soc. Jpn. 1972, 45, 2216.
8. Prakash, O.; Sharma, V.; Sadana, A. Synth. Commun. 1997, 27,
3371.
9. Mogilaiah, K.; Reddy, N.V.; Rao, R.B. Ind. J. Chem. 2001,
40B, 837.
10. Mogilaiah, K.; Kankaiah, G. Ind. J. Chem. 2002, 41B, 2394.
11. Mogilaiah, K.; Chowdary, D.S.; Reddy, P.R. Synth. Commun.
2002, 32, 857.
12. Mogilaiah, K.; Reddy, N.V. Synth. Commun. 2003, 33, 73.
13. Back, T.G.; Collins, S.; Kerr, R.G. J. Org. Chem. 1981, 46, 1564.
14. Hoffman, R.V.; Kumar, A. J. Org. Chem. 1984, 49, 4014.
15. Kocevar, M.; Mihokro, P.; Solanc, S. J. Org. Chem. 1995, 60, 1466.
16. Aldrich Catalog of Handbook of Fine Chemicals; 1996–1997; Vol. D3,
340–343, 459 pp.
17. Autenreith, W.; Spiess, P. Chem. Ber. 1901, 34, 188.
18. Kato, T.; Yamanaka, H.; Hamaguchi, F. Yakugaku. Zasshi. 1965,
85, 45; Chem. Abstr. 1965, 62, 13068.
19. Franzen, H.; Eichler, T. J. Prakt. Chem. 1908, 78, 162.
20. Dann, A.T.; Davies, W. J. Chem. Soc. 1929, 1050.
21. Yale, H.; Losee, K.; Martins, J.; Holsing, M. J. Am. Chem. Soc.
1953, 75, 1933.

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