JOURNAL OF CHEMICAL RESEARCH 2015
VOL. 39 JANUARY, 53–55
RESEARCH PAPER 53
Antimony (III) acetate as a versatile and efficient catalyst for synthesis of
14‑aryl‑14H‑dibenzo[a,j]xanthenes at room temperature
Fatemeh Hakimia* and Alireza Hassanabadib
aDepartment of Chemistry, Payamenoor University, PO Box 19395-3697 Tehran, Iran
bDepartment of Chemistry, Zahedan Branch, Islamic Azad University, PO Box 98135-978, Zahedan, Iran
Antimony (III) acetate was used in the one-pot three-component synthesis of biologically active 14-aryl-14H-dibenzo[a,j]
xanthenes from the condensation between arylaldehydes and β-naphthol under solvent-free conditions at ambient temperature.
This methodology has a number of advantages such as, short reaction time, easy work-up and high yields.
Keywords: Sb(OAc)3, 14‑aryl‑14H‑dibenzo[a,j]xanthenes, solvent‑free condition
14‑Aryl(alkyl)‑14H‑dibenzo[a,j]xanthenes
are
important
pharmaceutical activities. We have developed an efficient
procedure for the one‑pot three‑component synthesis of
biologically active heterocyclic compounds with anti‑viral,1
anti‑inflammatory2 and anti‑bacterial3 activities. Thus a broad
utility range has made xanthenes prime synthetic candidates
thereby accentuating the need to develop newer synthetic
routes for scaffold manipulation of xanthene derivatives.
biologically
active
14‑aryl‑14H‑dibenzo[a,j]xanthenes
in the presence of antimony(III)acetate as a solid phase
acidic catalyst, under solvent‑free conditions at an ambient
temperature (Scheme 1).
Several methods have been reported for the synthesis of
benzoxanthenes, such as the cyclocondensation reaction of
2‑hydroxyaromatic aldehydes and 2‑tetralone,4 the reaction
of benzaldehyde and acetophenone5 and the condensation of
β‑naphthol with alkyl or aryl aldehydes. The latter synthetic
method can be promoted by many Brønsted acid catalysts
such as: H2SO4, HCl, p‑toluenesulfonic acid, sulfamic acid,
methanesulfonic acid, H3PO4 or HClO4 at 0 °C in acetic acid,
ionic liquids, heteropolyacids, silica sulfuric acid, cyanuric
chloride, LiBr, CoPy2Cl2, Yb(OTf)3, Sc[N(SO2C8F17)2]3,
NaHSO4, Al(HSO4)3, bismuth(III)chloride, ZrO(OTf)2,
ruthenium chloride hydrate, silica supported perchloric acid,
P2O5/Al2O3 and silica chloride.6–11 Though different approaches
have been reported, there are many limitations, such as the
use of expensive and excess amounts of catalysts, elevated
temperatures, long reaction times, hazardous organic solvents
and reagents, and low yields. Hence, the development of
novel methods for the synthesis of functionalised biologically
active 14‑aryl(alkyl)‑14H‑dibenzo[a,j]xanthenes is of
great importance because of their potential biological and
Result and discussions
We have investigated the synthesis of 14‑aryl‑14H‑dibenzo[a,j]
xanthenes in the presence of antimony(III)acetate as catalyst.
First, the reaction of benzaldehyde (1 mmol) with 2‑naphthol
(2 mmol) was chosen as a model system (Scheme 2). Initially
a control experiment confirmed that the reaction did not
proceed in the absence of a catalyst (Table 1, entry 1). The
model reaction was then performed in the presence of different
catalysts and solvents at different temperatures.
We have carried out a model study with benzaldehyde
(1 mmol) and 2‑naphthol (2 mmol) using Sb(OAc)3 (0.02 g) as
catalyst at room temperature. In order to establish the better
catalytic activity of Sb(OAc)3, we have compared the reaction
using other catalysts at room temperature and for 15 min. The
results are listed in Table 1. The results show that Sb(OAc)3 is
a more efficient catalyst with respect to the reaction time and
exhibits broad applicability giving products in similar or better
yield (Table 1, entry 16).
Ar
O
OH
Sb(OAc)3
Solvent-free, r.t.
2
+
Ar
H
O
1
2
3a-m
Scheme 1 Synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes in the presence of antimony(III)acetate as catalyst.
O
OH
Sb(OAc)3
H
2
+
Solvent-free, r.t.
O
Scheme 2 Synthesis of 14-phenyl-dibenzo[a,j]xanthenes in the presence of Sb(OAc)3 as catalyst.
Hakimi, Fatemeh
