8146
K. Singh, S. Singh / Tetrahedron Letters 47 (2006) 8143–8146
6. (a) Cho, H.; Takeuchi, Y.; Ueda, M.; Mizuno, A.
Acknowledgements
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Rovnyak, G. C.; O’Reilly, B. C.; Schwartz, J. J. Org.
Chem. 1989, 54, 5898–5907.
We are thankful to the CSIR (01(1960)/04/EMR-II) and
UGC (F. 31-53/2005 (SR)), New Delhi, for financial
assistance, and National Single Crystal X-ray Diffraction
Facility, IIT Bombay, for X-ray analysis. S.S. thanks the
UGC, New Delhi, for a senior research fellowship.
7. (a) Folkers, K.; Johnson, T. B. J. Am. Chem. Soc. 1934,
56, 1374–1377; (b) George, T.; Tahilramani, R.; Mehta, D.
V. Synthesis 1975, 405–407.
8. In the case of entries 3, 9 and 10 (Table 2), when 3–4 equiv
of n-BuLi was used, the corresponding N3,C6-diacylated
products were obtained in low yields. However, entry 2
(Table 2) did not yield the corresponding N3,C6-diacy-
lated product, and only N3-acylated product was isolated
in 30% yield.
9. (a) Kappe, C. O.; Stadler, A. Org. React. 2004, 63, 1–116;
(b) Kappe, C. O. QSAR Comb. Sci. 2003, 22, 630–645; (c)
Singh, K.; Singh, J.; Deb, P. K.; Singh, H. Tetrahedron
1999, 55, 12873–12880; (d) Ma, Y.; Qian, C.; Wang, L.;
Yang, M. J. Org. Chem. 2000, 65, 3864–3868; (e) Singh,
K.; Arora, D.; Singh, S. Tetrahedron Lett. 2006, 47, 4205–
4207; (f) Singh, K.; Singh, S.; Kaur, P. Lett. Org. Chem.
2006, 3, 201–203.
Supplementary data
Experimental procedures and spectral data for all
compounds are given in the supplementary data. Sup-
plementary data associated with this article can be
References and notes
10. In our previous investigation,3 on deprotonation of the C6
Me of DHPMs, the trianion generated using LDA was of
a blood red color.
11. Crystallographic data for 6b have been deposited with the
Cambridge Crystallographic Data Centre (CCDC). The
coordinates can be obtained on request from the Director,
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK. The
CCDC Number is 614958.
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