Solvent-free Synthesis of 1,8-Dioxo-octahydroxanthenes and Tetra-hydrobenzo[a]
xanthene-11-ones over Poly(N,N
0
-dibromo-N-ethylnaphtyl-2,7-sulfonamide)
Ardeshir Khazaei ,
a
*
Mahshid Rezaei,
a
Ahmad Reza Moosavi-Zare
b
*
and Shahnaz Saednia
a
a
Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran
b
Department of Chemistry, Sayyed Jamaleddin Asadabadi University, Asadabad 6541835583, Iran
(Received: March 7, 2017; Accepted: June 21, 2017; DOI: 10.1002/jccs.201700082)
In this work, poly(N,N
0
-dibromo-N-ethylnaphtyl-2,7-sulfonamide) (PDNES) as a highly efficient
catalyst was applied for the synthesis of 1,8-dioxo-octahydroxanthenes and tetra-hydrobenzo[a]
xanthene-11-ones under neutral and solvent-free conditions.
Keywords: N-halo reagent; Poly(N,N
0
-dibromo-N-ethylnaphtyl-2,7-sulfonamide); Dimedone;
Aldehyde; 2-Naphthol.
INTRODUCTION
Multicomponent reactions (MCR
S
) are those in
which three or more compounds are combined together
in one step to generate a single product.
1
Some advan-
tages of MCRs are their simplicity, atom economy,
high yield, and synthetic efficiency compared to conven-
tional chemical reactions. For this purpose, the design
and implement of MCRs is very important in both aca-
demic research and industry.
2
Xanthene and benzoxanthene derivatives such as
1,8-dioxo-octahydroxanthenes and tetra-hydrobenzo[a]
xanthene-11-ones are one of the most privileged classes of
heterocyclic compounds that are widely used in organic
synthesis, pharmaceutical and biological research, and
industry.
3–13
For example, they have been applied in the
field of industry as dyes in laser technology,
3
PH-sensitive
fluorescent materials for visualization of biomolecules,
4
photodynamic therapy,
5
and also as antagonists for the
paralyzing action of zoxazolamine
6
and luminescent sen-
sors.
7
In the field of pharmaceutical and biological
research, they have been used as antibacterial,
8
antitumor,
9
antiviral,
10
anti-inflammatory,
11
and antican-
cer agents, as well as novel CCR1 receptor antagonists
12
and as antagonists for drug-resistant leukemia lines.
13
Because of these useful applications and valuable proper-
ties, xanthene derivatives synthesis is very important.
Some methods have been reported on the synthesis
of the xanthene derivatives, which include the synthesis
by cyclization of polycyclic aryltiflate esters,
14
intramolecular trapping of benzynes by phenols,
15
reac-
tion between aryloxy magnesium halides and triethyl
orthoformate,
16
and cyclocondensation of 2-hydroxyl
aromatic aldehyde with 2-tetralone.
17
Recently, the synthesis of 1,8-dioxo-octahydroxan-
thenes was reported by the reaction of 2 equiv of
dimedone(5,5-dimethyl-1,3-cyclohexane dione) with
1 equiv of various aldehydes in the presence of several
catalysts including SbCl
3
/SiO
2,
18
MCM-41-SO
3
H
(under ultrasonic irradiation),
19
CAN,
20
polyaniline
p-toluenesulfonate,
21
Fe(HSO
4
)
3,
22
DABCO-bromine,
23
cyanuric chloride,
24
and NaHSO
4
-SiO
2.
18
The most interesting protocol for the synthesis of
tetra-hydrobenzo[a]xanthene-11-one is the condensation
reaction between β-naphthol, arylaldehydes, and dime-
done using various catalysts such as NaHSO
4
/the ionic
liquid ([bmim] BF
4
),
25
InCl
3
/P
2
O
5,
26
perchloric acid
adsorbed on silica gel,
27
Zr(HSO
4
),
28
strontium triflate,
29
RuCl
4,
30
p-TSA,
31
and TrCl.
32
However, some of these
methods suffer from drawbacks such as low product
yields, long reaction times, harsh reaction conditions, and
the use of toxic and expensive catalysts.
With these issues in mind, we report a highly efficient
method for the synthesis of 1,8-dioxo-octahydroxanthenes
and tetra-hydrobenzo[a]xanthene-11-ones using poly (N,
N
0
-dibromo-N-ethylnaphtyl-2,7-sulfonamide) (PDNES)
44
benzaldehyde as a reusable, high stable, a rich source of
Br
+
, and an efficient catalyst under solvent-free conditions
(Schemes1and2).
*Corresponding author. Email: Khazaei_1326@yahoo.com; moosavizare@yahoo.com
J. Chin. Chem. Soc. 2017 1 © 2017 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
JOURNAL OF THE CHINESE
CHEMICAL SOCIETY Article