Fused pyrazino[2,3-b]indolizine and indolizino[2,3-b]quinoxaline derivatives; synthesis, structures, and properties

TETRAHEDRON

卷:67

Article

Bloch, Witold M.¹  Derwent-Smith, Stephanie M.¹  Issa, Fatiah²  Morris, Jonathan C.³  Rendina, Louis M.²  Sumby, Christopher J.¹ 

[1] Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia

[2] Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia

[3] Univ New S Wales, Sch Chem, Sydney, NSW 2052, Australia

关键词: Fused heterocycles;    Synthesis;    Organic dyes;    X-ray crystallography;    Biological activity;   

DOI  :  10.1016/j.tet.2011.09.133

来源: Elsevier

【 摘 要 】

The synthesis of six new compounds incorporating either a pyrazino[2,3-b]indolizine or indolizino[2,3-b] quinoxaline core are reported in good yield (58-87%). The intermediates for the key cyclization reaction for one set of compounds (5a-c), with a sterically demanding 3,5-dimethylpyrazole group in the 5-position of the core, were found to be mono-substituted. These intermediates could be isolated and cyclized by heating under acid-catalyzed conditions. To further demonstrate the versatility of the chemistry, compounds 6a-c were synthesized in 58-68% yields. Compounds 5a-c are non-planar in solution and the solid-state, while 6a-c have close to planar conformations, pointing to weak hydrogen bonds between the acidic C-Hs and the adjacent azine nitrogen atoms. The cytotoxicity of the six newly synthesized and three previously prepared compounds was assessed against a human glioblastoma multiforme cell line. (C) 2011 Elsevier Ltd. All rights reserved.

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