Efficient one-pot synthesis of 7-azacoumarins by knoevenagel reaction using water as reaction medium

Heterocycles

Volumn 45, Issue 9, 1997, Pages 1715-1721

  Brufola, Gianluca ^a   Fringuelli, Francesco ^a   Piermatti, Oriana ^a   Pizzo, Ferdinando ^a  

^a UNIVERSITY OF PERUGIA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0003515478     PISSN: 03855414     EISSN: None     Source Type: Journal    
DOI: 10.3987/com-97-7857     Document Type: Article

References (21)

1. T. M. Ibrahim, F. S. M. Ahmed, and S. A. Shedid, Phosphorus, Sulfur and Silicon, 1994, 86, 263.
2. a) F. Rovessac and A. Leclerc, Synthetic Commun., 1993, 23, 2709.
3. b) S. E. Drewes, O. L. Njamela, N. D. Emslie, N. Ramesar, and J. S. Field, Synthetic Commun., 1993, 23, 2807.
4. c) Y. El-Ahmad, J. D. Brion, and P. Reynaud, Heterocycles, 1993, 36, 1979.
5. d) H. M. F. Madkour, Heterocycles, 1993, 36, 947.
6. e) T. Harayama, K. Nakatsuka, H. Nishioka, K. Murakami, Y. Ohmori, Y. Takeuchi, H. Ishii, and K. Kenmotsu, Heterocycles, 1994, 38, 2729.
7. f) T. Harayama, K. Katsuno, H. Niscioka, M. Fujii, Y. Nishita, H. Ishii, and Y. Kaneko, Heterocycles, 1994, 39, 613.
8. g) G. Brufola, F. Fringuelli, O. Piermatti, and F. Pizzo, Heterocycles, 1996, 43, 1257.
9. a) R. B. Moffett, J. Org. Chem., 1970, 35, 3596.
10. b) K. V. Auwers, J. Prakt. Chem., 1938, 150, 166.
11. c) R. Robinson and J. S. Watt, J. Chem. Soc., 1934, 1536.
12. d) J. V. Dejardin and C. L. Lapire, Bull. Soc. Chim. France, 1978, 11-75.
13. e) F. Trecourt, F. Marsais, T. Gungor, and G Queguiner, J. Chem. Soc., Perkin Trans. 1, 1990, 2409.
14. f) D. Billeret, D. Blondeau, and H. Sliwa, J. Heterocycl. Chem., 1993, 30, 671.
15. a) F. Fringuelli, R. Germani, F. Pizzo, and G. Savelli, Tetrahedron Lett., 1989, 30, 14272.
16. b) F. Fringuelli, R. Germani, F. Pizzo, F. Santinelli, and G. Savelli, J. Org. Chem., 1992, 57, 1198.
17. c) F. Fringuelli, R. Pellegrino, and F. Pizzo, Synthetic Commun., 1993, 23, 3157.
18. d) F. Fringuelli, R. Pellegrino, O. Piermatti, and F. Pizzo, Synthetic Commun., 1994, 24, 2665.
19. e) F. Fringuelli, G. Pani, O. Piermatti, and F. Pizzo, Tetrahedron, 1994, 50, 11499.
20. nd Ed. VCH, 1988.
21. 7 In moderately basic solution, the pyridoxal is mainly an equilibrium mixture of the mono-anions of the hemiacetal and hydrated aldehyde. Under strongly alkaline conditions, the compound exists mainly as a dianion of hydrated aldehyde.