93828-11-6Relevant articles and documents
Synthesis of N-benzyl-des-D-ring lamellarin K via an acyl-Claisen/Paal-Knorr approach
Dittrich, Nora,Pilkington, Lisa I.,Leung, Euphemia,Barker, David
, p. 1881 - 1894 (2017/03/11)
Lamellarin K is a complex pyrrole natural product and member of the lamellarin family – a group of natural products known for their potent biological activities, such as, antiproliferative activity and inhibition of P-gp mediated drug efflux pumps. We herein describe the synthesis of the N-benzyl-des-D ring analogue of lamellarin K using a route that centres on an acyl-Claisen reaction to eventually prepare a highly-functionalised 1-aryl-4-methyl-1,4-diketone. Paal-Knorr pyrrole formation using this diketone undergoes auto-oxidation to give a fully-substituted 5-formyl pyrrole which was converted into the natural lactone B ring. Antiproliferative testing of the N-benzyl-des-D ring analogue gave an IC50 of 2.63?μM against the MDA-MB-231 breast cancer cell line.
Nucleophilic substitution of nitro groups by [18F]fluoride in methoxy-substituted ortho-nitrobenzaldehydes-A systematic study
Shen, Bin,L?ffler, Dirk,Reischl, Gerald,Machulla, Hans-Jürgen,Zeller, Klaus-Peter
experimental part, p. 216 - 224 (2009/07/25)
As model reactions for the introduction of [18F]fluorine into aromatic amino acids, the replacement of NO2 by [18F]fluoride ion in mono- to tetra-methoxy-substituted ortho-nitrobenzaldehydes was systematically investigated. Unexpectedly, the highly methoxylated precursors 2,3,4-trimethoxy-6-nitrobenzaldehyde and 2,3,4,5-tetramethoxy-6-nitrobenzaldehyde showed high maximum radiochemical yields (82% and 48% respectively). When the electrophilicity of the leaving group substituted carbon atom is expressed by its 13C NMR chemical shift a good correlation with the reaction rate at the beginning of the reaction (first min) was found (R2 = 0.89), whereas the maximum radiochemical yields correlated much poorer with this electrophilicity parameter. This may be caused by side reactions becoming influencial in the further reaction course. As possible side reactions the demethylation of methoxy groups and intramolecular redox reactions could be detected by HPLC/MS.
A new synthetic approach to 7-hydroxynitidine
Ramani, Prasanna,Fontana, Gabriele
, p. 5262 - 5264 (2008/12/21)
Benzo[c]phenanthridine alkaloid, 7-hydroxynitidine, was synthesized from readily available 2-benzyloxy-6-bromo-3,4-dimethoxybenzaldehyde 5 and napthylamine 6 using reductive amination followed by radical cyclization in eight steps. This method is highly e
