Synthesis of halogenated/nitrated flavone derivatives and evaluation of their affinity for the central benzodiazepine receptor
摘要:
A series of halogenated/nitrated flavone compounds were synthesized. Some of the products were found to be potent central benzodiazepine receptor (BDZ-R) ligands. The structure-activity relationships (SAR) analysis of the new synthetic compounds, together with that of others already described, indicates that substitutions at position 6 or 6 and 3' in the flavone nucleus are the only ones that give rise to high affinity BDZ-R ligands. (C) 1997 Elsevier Science Ltd.
Efficient Synthesis of Nitroflavones by Cyclodehydrogenation of 2′-Hydroxychalcones and by the Baker-Venkataraman Method
摘要:
Several nitroflavone derivatives were synthesized by cyclodehydrogenation of 2'-hydroxychalcones and by the Baker-Venkataraman approach, starting from 2'-hydroxyacetophenones and benzoic acid derivatives. Nitroflavones synthesised by the first synthetic approach were obtained in better global yields than those obtained by the later method. The structures of all new compounds were elucidated by microanalyses, 1D and 2D NMR, IR, and mass spectroscopic measurements.
Synthesis of 3-alkenyl-2-arylchromones and 2,3-dialkenylchromones via acid-catalysed retro-Michael ring opening of 3-acylchroman-4-ones
作者:David S. Clarke、Christopher D. Gabbutt、John D. Hepworth、B. Mark Heron
DOI:10.1016/j.tetlet.2005.06.058
日期:2005.8
3-Acylchromones and 3-acylflavones, readily available by acylation of 2'-hydroxydibenzoylmethane with acid anhydrides in the presence of base, undergo efficient conjugate reduction with NaBH4 in pyridine to give the corresponding chroman-4-ones/flavanones in high yields. The reduction is both regio- and chemoselective. Treatment of the chroman-4-ones with MeSO3H generates the 3-alkenyl-2-arylchromones by a dehydrative rearrangement initiated by retro-Michael cleavage of the pyranone ring. This reduction-rearrangement sequence can be extended to 2-alkyl-3-alkenoylchromones to generate 3-alkenyl-2-styrylchromones, the first examples of 2,3-dialkenylchromones. (c) 2005 Elsevier Ltd. All rights reserved.