A novel application of (Diacetoxyiodo)benzene for carbon-carbon cleavage of aryl diamines and synthesis of quinones

Article abstract of DOI:10.1055/s-0030-1258511

A novel synthetic utility of hypervalent iodine reagent, (diacetoxyiodo)benzene for diamino aryl carbon-carbon cleavage is described. 1,2-Diamino aryl compounds were successfully converted into the corresponding nitriles, while the developed method was also useful for the preparation of quinones from corresponding 1,4-diamino aryl compounds. The advantages of this protocol are shorter reaction times and mild reaction conditions to obtain moderate to good yields.

Full text of DOI:10.1055/s-0030-1258511

LETTER
2059
A Novel Application of (Diacetoxyiodo)benzene for Carbon–Carbon Cleavage
of Aryl Diamines and Synthesis of Quinones
N
ovel Application
i
of (Dia
k
cetoxyiodo)
a
benzene s N. Telvekar,* Harshal M. Bachhav
Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, Matunga, Mumbai 400 019, India
Fax +91(22)24145614; E-mail: vikastelvekar@rediffmail.com
Received 13 April 2010
only few methods reported, which include metal oxides in
Abstract: A novel synthetic utility of hypervalent iodine reagent,
combination with H2O2, where the low yields and forma-
(diacetoxyiodo)benzene for diamino aryl carbon–carbon cleavage
is described. 1,2-Diamino aryl compounds were successfully con-
tion of p-nitro aniline as a major side product is observed.5
verted into the corresponding nitriles, while the developed method
Thus, in this communication we report the novel applica-
was also useful for the preparation of quinones from corresponding
tion of hypervalent iodine reagent, (diacetoxyiodo)ben-
1,4-diamino aryl compounds. The advantages of this protocol are
zene for the oxidative cleavage of the carbon–carbon bond
shorter reaction times and mild reaction conditions to obtain mod-
of 1,2-diamino aryl compounds to the corresponding ni-
triles and preparation of quinones from corresponding
1,4-diamino aryl compounds. There are no prior reports in
the literature for oxidative cleavage of aryl diamines or
synthesis of quinone using hypervalent iodine reagents.
erate to good yields.
Key words: (diacetoxyiodo)benzene, 1,2-diamino aryl, carbon–
carbon cleavage, nitirle, quinone
We selected 1,2-diaminobenzene as a model substrate to
explore the suitable reaction conditions with (diacetoxy-
iodo)benzene in acetone at room temperature (Scheme 1).
In this case, the reaction afforded the corresponding
cis,cis-mucononitrile as the major product.6 We also
found that this oxidative transformation takes place in
chloroform and dichloromethane, but lower yields were
observed. To explore the possibility of other hypervalent
iodine reagents for conversion of 1,2-diaminobenzene
into cis,cis-mucononitrile, we carried out the reaction
with 1,2-diaminobenzene using various hypervalent
iodine reagents including IBX, KIO3, and 4,4′-bis-
(dichloroiodo)-biphenyl. Unlike the situtation with (diac-
etoxyiodo)benzene, no formation of cis,cis-mucononitrile
was observed even after long reaction times.
Hypervalent iodine reagents have attracted increasing in-
terest during the last decade because of their selective,
mild, and environmentally friendly properties as oxidiz-
ing agents in organic synthesis.1 The relevance of this
methodology stems from the fact that all the aforemen-
tioned transformations are quite fundamental in nature
and can be easily applied to a multitude of synthetic strat-
egies. Investigations from our laboratories have revealed
a series of new paradigms for hypervalent iodine mediated
reactions under mild conditions.2
(Diacetoxyiodo)benzene is a hypervalent iodine reagent
which is readily available and frequently used in several
oxidative transformations.3 During the course of our stud-
ies, we found that treatment of 1,2-diaminobenzene with
(diacetoxyiodo)benzene in acetone resulted into forma-
tion of cis,cis-mucononitrile by oxidative cleavage of a
carbon–carbon bond. It is interesting to note that, under
these reaction conditions, 1,3-diaminobenzene was unaf-
fected while 1,4-diaminobenzene unexpectedly led to for-
mation of benzoquinone.
NH2
CN
CN
DIB, acetone
10 min, r.t.
NH2
Scheme 1
In order to explore the reaction scope, a variety of substi-
tuted 1,2-diamino aryl compounds was prepared by stan-
dard reported procedures and converted into the
corresponding nitriles by oxidative carbon–carbon cleav-
age in moderate to good yields, and the results are summa-
rized in Table 1.7a
There are only three previously reported methods avail-
able for oxidative cleavage of the carbon–carbon bond of
1,2-diamino aryl compounds, in which compounds such
as 1,2-diaminobenzene are treated with molecular oxygen
in the presence of CuCl in pyridine and converted into
cis,cis-mucononitrile. In another method 1,2-diaminoben-
zene was oxidized using stoichiometric amount of nickel
peroxide or lead tetraacetate. However, all these reactions
have several drawbacks such as tedious workup, low
yields (less than 50%), and use of toxic reagents.4 In case
of quinone formation from 1,4-diaminobenzene, there are
It was found that electron-rich 1,2-diaminobenzenes were
suitable for this transformation, giving the dinitriles in
moderate to good yields in short reaction times (Table 1,
entries 2–4), while strongly electron-deficient 1,2-diami-
nobenzenes and heterocyclic diamines did not undergo
this transformation (Table 1, entries 8 and 9). It should be
noted that, under these reaction conditions, methoxy and
ester groups remain unaffected (Table 1, entries 4 and 5).
SYNLETT 2010, No. 14, pp 2059–2062
x
x
.x
x
.2
0
1
0
Advanced online publication: 22.07.2010
DOI: 10.1055/s-0030-1258511; Art ID: D09310ST
© Georg Thieme Verlag Stuttgart · New York

2060
V. N. Telvekar, H. M. Bachhav
LETTER
NH2
The reaction system is also useful for 1,2-diaminonaph-
thalene (Table 1, entry 7).
O
O
DIB, acetone
10 min, r.t.
Under the same reaction conditions, 1,4-diaminobenzene
reacted with (diacetoxyiodo)benzene in acetone to give
benzoquinone (Scheme 2).
NH2
Scheme 2
Considering this fact, we studied various substituted 1,4-
diaminobenzenes in acetone and obtained the correspond-
ing quinones in short reaction times (Table 1).7b The
method was also successfully applied to the synthesis of
napthaquinone and anthraquinone from the corresponding
diamino compounds (Table 1, entries 13–16).
Table 1 Reaction of (Diacetoxyiodo)benzene with Aryl Diamino Compoundsa
Entry
1
Substrate
Product
Time (min)
15
Yield (%)b
87
NH2
CN
CN
NH2
NH2
CN
CN
2
3
4
5
10
10
15
20
85
87
85
85
Cl
Cl
NH2
NH2
CN
CN
Me
Me
NH2
NH2
CN
CN
MeO
NH2
NH2
MeO
CN
CN
EtO2C
EtO2C
NH2
NH2
NH2
CN
CN
6
7
15
20
85
87
O
O
NH2
CN
NH2
CN
NH2
8
9
–
120
120
n.r.c
n.r.c
O2N
NH2
NH2
–
H2N
NH2
NH2
O
10
11
10
90
85
NH2
O
H2N
Cl
O
15
NH2
Cl
O
Synlett 2010, No. 14, 2059–2062 © Thieme Stuttgart · New York

LETTER
Novel Application of (Diacetoxyiodo)benzene
2061
Table 1 Reaction of (Diacetoxyiodo)benzene with Aryl Diamino Compoundsa (continued)
Entry
12
Substrate
Product
Time (min)
15
Yield (%)b
87
H2N
O
Me
NH2
Me
O
O
H2N
13
14
10
15
90
90
NH2
O
O
H2N
O
NH2
Cl
Cl
H2N
O
O
15
16
10
10
90
88
NH2
O
O
H2N
NH2
NH2
NH2
a Reaction conditions: substrate (4.6 mmol), (diacetoxyiodo)benzene (2 equiv) in acetone (15 mL), r.t.
b Isolated yields after column chromatography. Structures were confirmed by comparison of IR and 1H NMR spectra with those of authentic
materials.8
c n.r. = no reaction.
(4) (a) Kajimoto, T.; Takahashi, H. J. Org. Chem. 1976, 41,
1389. (b) Nakagawa, K.; Onoue, H. Tetrahedron Lett. 1965,
20, 1433. (c) Nakagawa, K.; Onoue, H. J. Chem. Soc.,
Chem. Commun. 1965, 396.
(5) (a) Maaiti, S.; Dinda, S.; Banerjee, S.; Mukherjee, A.;
Bhattacharyya, R. Eur. J. Inorg. Chem. 2008, 2038.
(b) Gharah, N.; Chakroborty, S.; Alok, M.; Bhattacharya, R.
Inorg. Chim. Acta 2009, 362, 1089.
In conclusion, we have exploited a novel application of
(diacetoxyiodo)benzene for oxidative cleavage of car-
bon–carbon aryl diamines to nitriles as well as a novel
route for the synthesis of quinones in short reaction times.
Both these applications are general, practical, economical,
and efficient.
(6) The cis–cis configuration was confirmed by using NMR,
melting point and comparing with literature. See:
(a) Elvidge, J. A.; Ralph, P. D. J. Chem. Soc., C 1966, 387.
(b) Campbell, C. D.; Ress, C. W. J. Chem. Soc., Chem.
Commun. 1965, 192. (c) Friedmann, G.; Gati, E.; Lahav, M.;
Robinovich, D.; Shakked, Z. J. Chem. Soc., Chem. Commun.
1975, 491.
Acknowledgment
V.N.T. thanks All India Council for Technical Education (AICTE)
for financial support under Research Promotion Scheme (RPS).
References and Notes
(7) (a) General Procedure for the Cleavage of 1,2-Diamino-
(1) (a) Zhdankin, V. V.; Stang, P. J. Chem. Rev. 2002, 102,
2523. (b) Zhdankin, V. V. Curr. Org. Synth. 2005, 2, 121.
(c) Wirth, T. Angew. Chem. Int. Ed. 2005, 44, 3656.
(2) (a) Telvekar, V. N.; Patel, K. N.; Kundaikar, H. S.;
Chaudhari, H. K. Tetrahedron Lett. 2008, 49, 2213.
(b) Telvekar, V. N.; Rane, R. M. Tetrahedron Lett. 2007, 48,
6051.
(3) (a) Kotali, A.; Harris, P. A. J. Heterocycl. Chem. 1996, 33,
605. (b) Kotali, A. Tetrahedron Lett. 1994, 36, 6753.
(c) Karade, N. N.; Shirodkar, S. G.; Patil, M. N.; Potrekar,
R. A.; Karade, H. N. Tetrahedron Lett. 2003, 44, 6729.
(d) Yusubov, M. S.; Chi, K.-W.; Park, J. Y.; Karimov, R.;
Zhdankin, V. V. Tetrahedron Lett. 2006, 47, 6305.
benzene (Table 1, Entry 1)
To a stirred solution of(diacetoxyiodo)benzene (3g, 9.2
mmol) in acetone (15 mL) was added 1,2-diaminobenzene
(0.5 g, 4.6 mmol). The reaction mixture was stirred at r.t.
until the starting material was completely consumed (TLC).
After completion of reaction, the reaction mixture was
quenched with H2O (20 mL) and further diluted with EtOAc
(30 mL). The organic layer was separated and washed
successively with 10% NaHSO4 solution (2 × 20 mL), 10%
NaHCO3 (2 × 15 mL), and H2O (2 × 20 mL). The organic
layer was dried over anhyd Na2SO4, filtered, and
concentrated under reduced pressure to give crude product.
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V. N. Telvekar, H. M. Bachhav
LETTER
Pure mucononitrile was obtained as a colorless solid after
silica gel column chromatography (10% EtOAc–hexane).
(b) General Procedure for the Oxidation of 1,4-
Diaminobenzene (Table 1, Entry 10)
To a stirred solution of(diacetoxyiodo)benzene (3g, 9.2
mmol) in acetone (15 mL) was added 1,4-diaminobenzene
(0.5 g, 4.6 mmol). The reaction mixture was stirred at r.t. and
after completion of reaction (TLC) the reaction mixture was
quenched in H2O and the above workup procedure was
followed to obtain benzoquinone.
1710, 1627, 1210, 803 cm–1. 1H NMR (300 MHz, CDCl3):
d = 3.86 (s, 3 H), 4.80 (s, 1 H), 5.67–5.71 (d, J = 12.0 Hz, 1
H), 7.05–7.09 (d, J = 12.0 Hz, 1 H). 13C NMR (75 MHz,
CDCl3): d = 29.6, 101.6, 105.9, 113.4, 113.9, 138.1, 148.0.
ESI-MS: m/z = 134 [M+].
(2E,4Z)-3-Benzoylhexa-2,4-dienedinitrile (Entry 6)
Mp 95 °C. IR (KBr): 3019, 2214, 1638, 1401, 1319 cm–1. 1H-
NMR (300 MHz, CDCl3): d = 5.75–5.78 (d, J = 10.8 Hz, 1
H), 5.82 (s, 1 H), 7.27–7.30 (d, J = 10.8 Hz, 1 H), 7.48–7.79
(m, 5 H). 13C NMR (75 MHz, CDCl3): d = 106.3, 108.4,
113.8, 114.0, 129.1, 130.0, 134.5, 135.0, 140.3, 153.1,
191.2. ESI-MS: m/z = 208 [M+].
(8) (2E,4Z)-3-Chlorohexa-2,4-dienedinitrile (Entry 2)
Mp 90 °C (lit.4 mp 89–90 °C). IR (KBr): 3050, 2220, 1640,
1111, 784 cm–1. 1H NMR (300 MHz, CDCl3): d = 5.83–5.85
(d, J = 6.0 Hz, 1 H), 5.89 (s, 1 H), 7.32–7.31 (d, J = 6.0 Hz,
2 H). 13C NMR (75 MHz, CDCl3): d = 105.6, 105.9, 135.7,
138.1, 147.9, 162.7. ESI-MS: m/z = 137 [M+].
1-Chloroanthracene-9,10-dione (Entry 15)
Mp 162 °C. IR (KBr): 3082, 1669, 1574, 1318, 1264, 702
cm–1. 1H NMR (300 MHz, CDCl3): d = 7.69–8.30 (m, 7 H).
13C NMR (75 MHz, CDCl3): d = 127.54, 128.3, 130.3, 133.1,
134.4, 134.7, 135.3, 135.8, 138.5, 182.6, 183.0. ESI-MS:
m/z = 242 [M+].
(2E,4Z)-3-Methylhexa-2,4-dienedinitrile (Entry 3)
Mp 57 °C (lit.4 mp 56.5–57.5 °C). IR (KBr): 3071, 2214,
1640, 1261, 1031, 797 cm–1. 1H NMR (300 MHz, CDCl3):
d = 2.41 (s, 3 H), 5.51 (s, 1 H), 5.68–5.70 (d, J = 5.4 Hz, 1
H), 7.24–7.26 (d, J = 5.4 Hz, 1 H). 13C NMR (75 MHz,
CDCl3): d = 20.6, 102.4,105.2, 115.0, 115.7, 143.5, 153.1.
ESI-MS: m/z = 118 [M+].
2-Aminoanthracene-9,10-dione (Entry 16)
Mp 303–306 °C. IR (KBr): 3434, 3331, 1673, 1625, 1588,
1337, 714 cm–1. 1H NMR (300 MHz, DMSO): d = 6.68 (s, 2
H), 6.92–8.10 (m, 7 H). 13C NMR (75 MHz, DMSO): d =
109.8, 118.2, 126.5, 129.7, 133.4, 133.5, 134.4, 135.0,
154.8, 180.2. ESI-MS: m/z = 224 [M + H]+.
(2E,4Z)-3-Methoxyhexa-2,4-dienedinitrile (Entry 4)
Mp 116 °C(lit.4 mp 116–117 °C). IR (KBr): 3061, 2214,
Synlett 2010, No. 14, 2059–2062 © Thieme Stuttgart · New York