RSC Advances
Paper
microscopy (TEM) was carried out on a Philips CM10 instrument
operating at 100 kV.
ILs
APTS
TCT
Ionic liquids
(3-Aminopropyl)triethoxysilane
1,3,5-Trichlorotriazine
General procedure for preparation of
[(PATDBP)(HSO4)2@HNT]
DIPEA
p-TSA
TLC
N,N-Diisopropylethylamine
p-Toluenesulfonic acid
Thin layer chromatography
Preparation of [PA@HNT]. First, HNT (2 g) was dispersed
ultrasonically in 8 mL 3-aminopropyltriethoxysilane (APTS) for
5 min at room temperature. Then, the suspension was exposed
to microwave irradiation in a closed vessel at 100 ꢁC and a power
of 25 W under constant stirring for 1 h. Finally, the precipitate
(PA@HNT) was ltered, washed with ethanol (2 ꢃ 10 mL), and
Conflicts of interest
ꢁ
The authors declare no conict of interest.
dried in a vacuum oven at 80 C.
Preparation of [PAT@HNT]. The obtained PA@HNT (2 g) was
dispersed in 25 mL dry THF by sonication for 10 min and then,
1,3,5-trichlorotriazine (20 mmol, 3.68 g) and DIPEA (14.4 mmol,
2.5 mL) were added and the mixture was stirred for 24 hours
under N2 at 0 ꢁC. Finally, the precipitate PAT@HNT was ltered,
washed with THF (2 ꢃ 10 mL) and acetone (10 mL), and dried in
Acknowledgements
We are grateful to the Research Council of the University of
Isfahan for nancial support of this work (project number
1015).
ꢁ
a vacuum oven at 80 C.
References
Preparation of [(PATDBP)Cl2@HNT].
A
mixture of
PAT@HNT (2 g) and DIPEA (11.5 mmol, 2 mL) was intensely
dispersed in 17 mL pyridine and then, the reaction mixture was
reuxed for 24 hours. Finally, the mixture was ltered, washed
with toluene three times and dried under vacuum to afford
[(PATDBP)Cl2@HNT].
Preparation of [(PATDBP)(HSO4)2@HNT]. The nanocatalyst
[(PATDBP)(HSO4)2@HNT] was generated by addition of NaHSO4
(5 g) to a dispersed mixture of [(PATDBP)Cl2@HNT] (2 g) in Mili-
Q water (30 mL) at room temperature and then, was shaken for
24 hours. The resulting light brown solid was collected by
ltration, washed with H2O (3 ꢃ 10 mL) to remove the
unreacted NaHSO4, and nally dried in a vacuum oven at 80 ꢁC
for 5 hours.
1 (a) K. S. Egorova, E. G. Gordeev and V. P. Ananikov, Chem.
Rev., 2017, 117, 7132–7189; (b) K. Dong, X. Liu, V. Dong,
X. Zhang and S. Zhang, Chem. Rev., 2017, 117, 6636–6695;
(c) C. Dai, J. Zhang, C. Huang and Z. Lei, Chem. Rev., 2017,
117, 6929–6983; (d) B. Wang, L. Qin, T. Mu, Z. Xue and
G. Gao, Chem. Rev., 2017, 117, 7113–7131; (e) M. Watanabe,
M. L. Thomas, S. Zhang, K. Ueno, T. Yasuda and K. Dokko,
Chem. Rev., 2017, 117, 7190–7239; (f) H. J. Jiang, S. Imberti,
B. A. Simmons, R. Atkin and G. G. Warr, ChemSusChem,
2019, 12, 270–274.
2 (a) B. Sarmah and R. Srivastava, J. Mol. Catal. A: Chem., 2017,
427, 62–72; (b) R. S. Tukhvatshin, A. S. Kucherenko,
Y. V. Nelyubina and S. G. Zlotin, ACS Catal., 2017, 7, 2981–
2989; (c) T. Wang, W. Wang, Y. Lyu, X. Chen, C. Li,
Y. Zhang, X. Song and Y. Ding, RSC Adv., 2017, 7, 2836–
2841; (d) R. Kukawka, A. Pawlowska-Zygarowicz,
J. Dzialkowska, M. Pietrowski, H. Maciejewski, K. Bica and
M. Smiglak, ACS Sustain. Chem. Eng., 2019, 7, 4699–4706.
3 (a) M. J. Saif, H. M. Asif and M. Naveed, J. Chil. Chem. Soc.,
2018, 63, 4109–4125; (b) X. Ding, H. Wang, W. Chen, J. Liu
and Y. Zhang, RSC Adv., 2014, 4, 41993–41996; (c) L. Duan,
W. Huang and Y. Zhang, RSC Adv., 2015, 5, 6666–6674; (d)
Z. Hajizadeh and A. Maleki, J. Mol. Catal., 2018, 460, 87–93.
4 (a) N. Y. Baran, T. Baran and A. Mente¸s, Appl. Clay Sci., 2019,
General procedure for synthesis of naphthopyranopyrimidine
derivatives catalyzed by [(PATDBP)(HSO4)2@HNT]
A mixture of b-naphthol (1 mmol), aromatic aldehyde (1 mmol),
N,N-dimethylbarbituric
acid
(1
mmol),
and
[(PATDBP)(HSO4)2@HNT] (2 mol%, 28 mg) was stirred at 100 ꢁC
under solvent-free conditions for the appropriate time accord-
ing to Scheme 3. The progress of the reaction was tested by TLC
(eluent : petroleum ether/EtOAc, 4 : 1). Aer completion of the
reaction, the mixture was cooled to room temperature and
CHCl3 (5 mL) was added. The catalyst was separated by centri-
fugation and washed with EtOH (5 mL). The products were
obtained by recrystallization from EtOH and dried under
reduced pressure. In some cases, the organic residue was
puried by column chromatography on silica gel (petroleum
ether/ethyl acetate) to provide the pure product in 90–98%
isolated yields (Scheme 3, 4a–n).
´
181, 105225–105237; (b) N. Balsamo, S. Mendieta, A. Heredia
and M. Crivello, J. Mol. Catal., 2020, 481, 110290–110299; (c)
V. Bertolino, G. Cavallaro, G. Lazzara, S. Milioto and F. Parisi,
Langmuir, 2017, 33, 3317–3323; (d) S. Sadjadi, M. M. Heravi,
M. Malmir and B. Masoumi, Appl. Organomet. Chem., 2018,
32, 4113–4125; (e) S. Sadjadi, M. M. Heravi, M. Malmir and
F. G. Kahangi, Appl. Clay Sci., 2018, 162, 192–203; (f)
S. Sadjadi, M. Malmir and M. M. Heravi, Appl. Clay Sci.,
2019, 168, 184–195; (g) S. Sadjadi, G. Lazzara, M. M. Heravi
and G. Cavallaro, Appl. Clay Sci., 2019, 182, 105299–105313;
(h) B. Eekhari far and M. Nasr-Esfahani, Appl. Organomet.
Chem., 2020, 34, 5406–5419.
Abbreviations
MCR
HNTs
Multicomponent reaction
Halloysite nanotubes
11982 | RSC Adv., 2021, 11, 11976–11983
© 2021 The Author(s). Published by the Royal Society of Chemistry