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and recyclable catalyst, (iv) solvent-free reaction conditions, (v)
short reaction times and (vi) high yields of products. We strongly
believe that this methodology would find wide usage in multistep
organic synthesis.
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2. Experimental procedure
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To a mixture of (Boc)2O (1.0 mmol) and Amberlyst-15 (15%, w/
w) was added an amine (1.0 mmol) and the mixture was stirred at
room temperature for the time indicated in Table 2. After comple-
tion of the reaction (indicated by TLC), CH2Cl2 (10 mL) was added
and the catalyst was separated by filtration. The filtrate was col-
lected and concentrated. The residue was purified by column chro-
matography to obtain the pure product. The recovered catalyst was
recycled for consecutive three times for the above reaction to fur-
nish the product with a little variation in yields (Table 1, entry 4).
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Acknowledgement
18. Heydari, A.; Kazem Shiroodi, R.; Hamadi, H.; Esfandyari, M.; Pourayoubi, M.
Tetrahedron Lett. 2007, 48, 5865.
19. Upadhyaya, D. J.; Barge, A.; Stefania, R.; Cravotto, G. Tetrahedron Lett. 2007, 48,
8318.
20. Sunitha, S.; Kanjilal, S.; Reddy, P. S.; Prasad, R. B. N. Tetrahedron Lett. 2008, 49,
2527.
The authors sincerely thank the management of Institute of Life
Sciences for continuous encouragement and support.
21. Suryakiran, N.; Prabhakar, P.; Srikanth Reddy, T.; Rajesh, K.; Venkateswarlu, Y.
Tetrahedron Lett. 2006, 47, 8039.
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