J IRAN CHEM SOC
16. S. Khaksar, A. Heydari, M. Tajbakhsh, S.M. Vahdat, J. Fluorine
Chem. 131, 1377 (2010)
17. M. Sheykhan, M. Mohammadquli, A. Heydari, J. Mol. Struct.
reaction conditions was studied again. When the reaction
completed, ethyl acetate was added and the catalyst was
separated by filtration. The recovered catalyst was washed
with ethyl acetate, dried and reused for the same reaction.
This process was carried out over five runs and all reactions
were led to the desired products without significant changes
in terms of the reaction time and yield which clearly dem-
onstrates practical recyclability of this catalyst.
1027, 156 (2012)
18. J.C. Jochims, Chem. Ber. 98, 2128 (1965)
19. Y. Han, l. Cai, Tetrahedron lett. 38, 5423 (1997)
20. S.K. guchhait, g. Priyadarshani, V. Chaudhary, D.R. Seladiya,
T.M. Shah, N.P. Bhogayta, RSC Adv. 3, 10867 (2013)
21. J. Wang, J. Hou, J. Wen, J. Zhang, X. Yu, Chem. Commun. 47,
3652 (2011)
22. Y. Jo, J. Ju, J. Choe, K.H. Song, S. lee, J. Org. Chem. 74, 6358
(2009)
23. I.M. Downie, M.J. Earle, H. Heaney, K.F. Shuhaibar, Tetrahedron
49, 4015 (1993)
Conclusion
24. A. Jackson, O. Meth-Cohn, J. Chem. Soc. Chem. Commun. 1319
(1995)
In conclusion, we have used of RHA-SO3H as a highly
powerful solid acid catalyst for the simple and efficient
synthesis of N,Nʹ-diarylformamidines and chemoselec-
tive synthesis of formamides from the reaction of various
aromatic amines and ethyl orthoformate and formic acid,
respectively. The procedure has several advantages such
as high reaction rates, ease of preparation and handling of
the catalyst, simple and green experimental procedure and
use of inexpensive and reusable catalyst. Furthermore, this
process avoids problems associated with the use of liquid
acids, which makes it a useful and attractive strategy in
view of economic and environmental advantages. Further
work to explore this catalyst in other organic transforma-
tions is in progress.
25. K. Kobayashi, S. Nagato, M. Kawakita, O. Morikawa, H. Koni-
shi, Chem. lett. 24, 575 (1995)
26. g. Pettit, M. Kalnins, T. liu, E. Thomas, K. Parent, J. Org. Chem.
26, 2563 (1961)
27. J. Martinez, J. laur, Synthesis 979 (1982)
28. K. Iseki, S. Mizuno, Y. Kuroki, Y. Kobayashi, Tetrahedron 55,
977 (1999)
29. F.F. Blicke, C. lu, J. Am. Chem. Soc. 74, 3933 (1952)
30. P.g. Reddy, g.D.K. Kumar, S. Baskaran, Tetrahedron lett. 41,
9149 (2000)
31. P. Strazzolini, A.g. giljanmi, S. Cauci, Tetrahedron 46, 1081 (1990)
32. l. Ma’mani, M. Sheykhan, A. Heydari, M. Faraji, Y. Yamini,
Appl. Catal. A 377, 64 (2010)
33. g. Brahmachari, S. laskar, Tetrahedron lett. 51, 2319 (2010)
34. B. Krishnakumar, M. Swaminathan, J. Mol. Catal. A Chem. 334,
98 (2011)
35. M.I. Ansari, M.K. Hussain, N. Yadav, P.K. gupta, K. Hajela, Tet-
rahedron lett. 53, 2063 (2012)
36. S.P. Pathare, R.V. Sawant, K.g. Akamanchi, Tetrahedron lett. 53,
3259 (2012)
Acknowledgments We are thankful to the University of guilan
Research Council for the partial support of this work.
37. X.J. Yang, Y.S. Zhang, Res. Chem. Intermed. 39, 2843 (2013)
38. S. Majumdar, J. De, J. Hossain, A. Basak, Tetrahedron lett. 54,
262 (2013)
39. D. Habibi, P. Rahmani, Z. Akbaripanah, J. Chemistry 1 (2013)
40. T. Okuhara, Chem. Rev. 102, 3641 (2002)
41. C. Real, M.D. Alcalá, J.M. Criado, J. Am. Ceram. Soc. 79, 2012
(1996)
References
1. R.J. grout, The chemistry of amidines and imidates (Wiley, New
York, 1975) Chapter 6
2. P.D. Evans, J.D. gee, Nature 287, 60 (1980)
3. S. Delarue, S. girault, F.D. Ali, l. Maes, P. grellier, C. Sergher-
aert, Chem. Pharm. Bull. 49, 933 (2001)
42. Q. Feng, H. Yamamichi, M. Shoya, S. Sugita, Cem. Concr. Res.
34, 521 (2004)
43. D. An, Y. guo, Y. Zhu, Z. Wang, Chem. Eng. J. 162, 509 (2010)
44. W. Tan, S. Yap, A. Matsumoto, R. Othman, F. Yeoh, Adsorption
17, 863 (2011)
45. F. Shirini, M. Mamaghani, M. Seddighi, Catal. Commun. 36, 31
(2013)
4. A.I. Meyers, Tetrahedron 48, 2589 (1992)
5. M.A. Matulenko, A.I. Meyers, J. Org. Chem. 61, 573 (1996)
6. P.S. Furth, M.S. Reitman, A.F. Cook, Tetrahedron lett. 38, 5403
(1997)
7. R.E.F. Boto, R.M. El-Shishtawy, P.F. Santos, l.V. Reis, P.
Almeida, Dyes Pigments 73, 195 (2007)
8. M. Cibian, S. langis-Barsetti, g. S. Hanan, Synlett 405 (2011)
9. Y. Wu, C. Yeh, Z. Chan, C. lin, C. Yang, J. Chen, J. Wang, J.
Mol. Struct. 890, 48 (2008)
46. F. Shirini, S. Akbari-Dadamahaleh, A. Mohammad-Khah, Chin.
J. Catal. 34, 2200 (2013)
47. M. Seddighi, F. Shirini, M. Mamaghani, RSC Adv. 3, 24046
(2013)
48. R.M. Roberts, J. Am. Chem. Soc. 72, 3603 (1950)
49. A. Porcheddu, g. giacomelli, I. Piredda, J. Comb. Chem. 11, 126
(2009)
50. D. Habibi, M. Nasrollahzadeh, C. R. Chimie 16, 1008 (2013)
51. Z. Wang, M. lu, RSC Adv. 4, 1234 (2014)
52. N. Ortega, C. Richter, F. glorius, Org. lett. 15, 1776 (2013)
53. O. lopez, S. Maza, V. Ulgar, I. Maya, J.g. Fernandez-Bolanos,
Tetrahedron 65, 2556 (2009)
10. S.J. Archibald, N.W. Alcock, D.H. Busch, D.R. Whitcomb, Inorg.
Chem. 38, 5571 (1999)
11. D.Y. Melgarejo, g.M. Chiarella, J.P.F. Jr, Inorg. Chim. Acta 378,
297 (2011)
12. V.l. Claisen, Ann 287, 360 (1895)
13. R.M. Roberts, P.J. Vogt, J. Am. Chem. Soc. 78, 4778 (1956)
14. R.M. Roberts, R.H. DeWolfe, J. Am. Chem. Soc. 76, 2411 (1954)
15. C. lin, C. Tsai, H. Chang, Catal. lett. 104, 135 (2005)
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