Title:Fe3O4@SiO2@KIT-6 as an Efficient and Reusable Catalyst for the Synthesis of Novel Derivatives of 3,3'-((Aryl-1-phenyl-1H-pyrazol-4- yl)methylene)bis (1H-indole)
Volume: 20
Issue: 6
Author(s): Mohammad Nikpassand*, Leila Zare Fekri and Mozhdeh Nabatzadeh
Affiliation:
- Department of Chemistry, Rasht Branch, Islamic Azad University, Rasht,Iran
Keywords:
Fe3O4@SiO2@KIT-6, diindolylmethane, Indole, room temperature, reusable catalyst, aqua media.
Abstract: Aim and Objective: Korea advanced institute of science and technology cubic ordered
mesoporous silica (KIT-6 mesoporous) silica coated magnetite nanoparticles, is an effective, ecobenign
and recyclable catalyst for the electrophilic substitution reactions of indoles with various
synthetized aldehydes to afford the corresponding novel diindolylmethanes in high yields and short
reaction times. The catalyst can be recovered and reused without loss of activity. The work-up of the
reaction consists of a simple separation, followed by concentration of the crude product and
purification. The present methodology offers several advantages such as aqueous media, excellent
yields, simple procedure, mild conditions and reduced environmental consequences. All of
synthesized compounds are new and were characterized by IR, NMR and elemental analyses.
Materials and Methods: A mixture of synthetized pyrazolecarbaldehydes [24] (2.0mmol), indole
(4.0mmol) and Fe3O4@SiO2@KIT-6 (0.04mmol) and H2O (10mL) were stirred at room temperature
for the required reaction time according to Table 2. After completion of the reaction, the product was
solved in CHCl3 (3×10 mL) and insoluble catalyst was removed by filtration in the presence of an
efficient magnetic bar. The organic phase including the product and CHCl3 was evaporated under
vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure
products.
Results: As part of our on interest for the development of efficient and environmentally friendly
procedures for the synthesis of heterocyclic and pharmaceutical compounds, an efficient, facile and
aqueous media was introduced for the synthesis of novel derivatives of diindolylmethanes containing
pyrazole moiety. A variety of synthetized aldehyde compounds reacted smoothly with indoles to
produce diindolylmethanes under these reaction conditions. The electron deficiency and the nature of
the substituents on the aromatic ring show some effects on this conversion. All the reactions were
run with catalytic amounts of catalysts. The best results gained with 0.04mmol of
Fe3O4@SiO2@KIT-6 as a strong Lewis acid at room temperature in aqueous media.
Conclusion: In conclusion, we have investigated the synthesized KIT-6 mesoporous silica coated
magnetite nanoparticles (MMNPs) as a mild and efficient catalyst for the synthesis of novel
diindolylmethanes coupled with pyrazole moiety in aqua media. The simplicity, easy workup
together with the use of inexpensive, environmentally friendly and reusable catalyst, is the notable
features of this catalytic procedure. To the best of our knowledge, this is the first report for the
synthesis of a new library of diindolylmethane compound bearing pyrazole moiety that enhance the
biological and pharmacological activity.
