68437-46-7Relevant academic research and scientific papers
PRODRUGS COMPRISING AN AMINOALKYL GLYCINE LINKER
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Page/Page column 105; 106, (2016/04/09)
The present invention relates to novel prodrugs of primary or secondary amine- or hydroxyl- comprising biologically active moieties and pharmaceutically acceptable salts thereof, prodrug reagents, pharmaceutical compositions comprising said prodrugs and t
Synthesis of 6-Acetyl-3-alkyl-2-phenyl-chromen-4-ones by Phasetransfer Catalysed Baker-Venkataraman Reaction
Henning, H.-G.,Schwabe, B.,Kernchen, F.,Westphal, G.
, p. 491 - 501 (2007/10/02)
Three of the five partial steps of the Baker-Venkataramansynthesis of flavones (scheme 1) can be flavoured by PTC conditions.In the intermolecular O-acylations of the 4-hydroxyacetophenone 1 (A) and the 5-acetyl-2-hydroxy-acylophenones 3 (C), respectively, the nucleophilicity of the phenolat anions is increased by the PT catalysator.The steric and electronic effects of the substituents in the 5-acetyl-2-benzoyloxy-acylophenones 4 cause the formation of the 6-acetyl-flavones 6 in the phasetransfer catalysed Baker-Venkataraman rearrangement (D) in one step and in good yields.The over-all yields of the 1 -> 6 reactions are not higher than 30percent because of the limiting step (B).This Fries rearrangement of 4-acyloxy-acetophenones 2 affords only 32-62percent of 3 under drastically enhanced conditions.
