Contrasting Behaviour of NBS towards 1,4-Dihydro-Benzothieno[3,2-B]Pyridine 5,5-Dioxides and 4,5-Dihydro-1H-Indeno[1,2-B]Pyridines

Tetrahedron 2013
B. Cekavicus, B. Vīgante, M. Rucins, K. Birkmane, M. Petrova, Sergejs Beļakovs, L. Zuka, A. Plotniece, K. Pajuste, M. Gosteva, A. Sobolev

Polycyclic 1,4-dihydrobenzothieno[3,2-b]pyridine 5,5-dioxides and 4,5-dihydro-1H-indeno[1,2-b]pyridines having ester or cyano group at the position 3 of dihydropyridine ring have been synthesised. Reactivity of N-bromosuccinimide (NBS) towards polycyclic 1,4-dihydropyridine derivatives has been investigated. It has been found that 1,4-dihydrobenzothieno[3,2-b]pyridine 5,5-dioxides are easily oxidised with NBS in methanol at rt in high yields, whereas 4,5-dihydro-1H-indeno[1,2-b]pyridines in reaction with NBS in methanol are brominated at 4a position affording stable 4a-bromo-4a,5-dihydroindeno[1,2-b]pyridine-3-carboxylates or unstable 3-carbonitriles, which rapidly undergo dehydrobromination reaction leading to the corresponding 5H-indeno[1,2-b]pyridine-3-carbonitriles.

Atslēgas vārdi
Polycyclic 1,4-dihydropyridines; Cyclisation; Bromination; Oxidation; N-Bromosuccinimide
DOI
10.1016/j.tet.2013.04.060
Hipersaite
http://www.sciencedirect.com/science/article/pii/S004040201300598X

Cekavicus, B., Vigante, B., Rucins, M., Birkmane, K., Petrova, M., Beļakovs, S., Zuka, L., Plotniece, A., Pajuste, K., Gosteva, M., Sobolev, A. Contrasting Behaviour of NBS towards 1,4-Dihydro-Benzothieno[3,2-B]Pyridine 5,5-Dioxides and 4,5-Dihydro-1H-Indeno[1,2-B]Pyridines. Tetrahedron , 2013, Vol.69, Iss.26, 5550.-5557.lpp. ISSN 0040-4020. Pieejams: doi:10.1016/j.tet.2013.04.060

Publikācijas valoda
English (en)