Paper
NJC
services of the University of Vigo (CACTI) for the NMR, MS and
X-ray diffraction work.
Notes and references
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Fig. 2 Representation of 2D supramolecular architecture of [NH
2
COG][TsO]
accessed March 2017.
(5) by hydrogen bonding interactions. Colour code: O, red; N, blue; C, grey;
S, yellow; C, grey.
5
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Fig. 3 X-ray structure of [NH
2
COG][TsO] (5). Selected bond lengths (Å)
and angles (1) are: C(1)–O(1) 1.216(3); C(1)–N(1) 1.322(4); C(1)–N(2) 11 D. Li, F. Shi, S. Guo and Y. Deng, Tetrahedron Lett., 2005,
1
.396(3); N(1)–H(1A) 0.840(18); N(1)–H(1B) 0.855(19); C(2)–N(3) 1.304(3);
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C(2)–N(4) 1.315(4); C(2)–N(2) 1.347(3); N(2)–H(2) 0.862(18); N(3)–H(3A)
1
1
1
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.865(19); N(3)–H(3B) 0.855(18); N(4)–H(4A) 0.849(18); N(4)–H(4B)
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S(1)–C(3) 1.749(3); C(4)–C(3) 1.3900(X).
Conclusion
1
1
1
In summary, we have developed a new procedure to synthesize
e-caprolactam by using a novel salt, cyanoguanidinium p-toluene-
sulfonate, which is able to catalyze the Beckmann rearrangement
of cyclohexanone oxime without the need of any other promoter.
High reaction temperatures and toxic solvents are avoided; the
catalyst is not corrosive and is easy to prepare.
1
1
2
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Experimental section
See ESI.†
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Conflicts of interest
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37, 80.
5 J. Gui, Y. Deng, Z. Hu and Z. Sun, Tetrahedron Lett., 2004,
5, 2681.
There are no conflicts to declare.
2
Acknowledgements
4
We thank the Xunta de Galicia (REGALIs Network R2014/015) 26 W. Bonrath, J. M. Leveque, V. Ragaini and R. Turgis, WO
for their financial support, as well as the research support Pat., 145312, 2008.
New J. Chem.
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