ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Synthesis of new 5-bromo derivatives of indole and spiroindole phytoalexins
Lucia Očenášová, Peter Kutschy, Jozef Gonda, Martina Pilátová, Gabriela Gönciová, Ján Mojžiš, and Pavel Pazdera
aDepartment of Organic Chemistry, Institute of Chemical Science, Faculty of Science, P. J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovakia
Abstract: Electrophilic aromatic substitution is one of the most thoroughly studied reactions in organic chemistry. In the present paper, the 5-brominated spirobrassinol methyl ethers VII, VIII were obtained by electrophilic substitution of the aromatic core of indoline at the C-5 position in the presence of various brominating agents. The same products were also prepared from 5-bromoindole (IX) following the sequence for the synthesis 1-methoxyspirobrassinol methyl ether (V) from indoline. In addition, the new related 5-bromospiroindoline derivatives XX–XXIII were synthesised and their biological activity on human tumour cell lines was examined. The presence of bromine in the indole or indoline skeleton at the C-5 position resulted in the partial increase in anticancer activity on leukaemia cell lines (Jurkat, CEM). The structures of the newly prepared products were determined by 1H and 13C NMR spectroscopy, including HSQC, HMBC, COSY, NOESY and DEPT measurements.
Keywords: 5-bromobrassinin – spiroindole phytoalexins – bromination – spirocyclisation – anti-proliferative activity
Full paper is available at www.springerlink.com.
Chemical Papers 70 (5) 635–648 (2016)