Tricyclic Quinazoline Alkaloids Conjugated to Ferrocene: Synthesis, Structure, and Redox Behavior of Ferrocenylmethylene‐Substituted 7H‐Deoxyvasicinones

Abstract

Abstract:The first organometallic derivatives of tricyclic quinazoline derivatives are prepared by condensation of the active C-3 methylene group of 7H-deoxyvasicinones with ferrocenecarbaldehyde. By following this route the conjugated parent alkaloid and derivatives with nitro, amino, as well as some alkanoylamino groups at C-7 were attached at the ferrocene moiety, thereby significantly extending the π system. In addition, the parent compound was subjected to the reaction by treatment with ferrocene-1,1′-dicarbaldehyde, giving rise to the

Improved Syntheses of 1,2‐Disubstituted Ferrocenes

“…Its stability against heat and air, its three‐dimensional shape, and its redox activity are most striking. Such properties facilitate the formation of planar‐chiral derivatives and the exploitation of the facile rotation of the cyclopentadienyl ligands as a “hinge” in larger structures, for example in extended π‐systems In addition, ferrocene finds applications in many areas such as catalysis, materials sciences, bioorganometallic chemistry, and electroanalytical methods . These fields and many others have been reviewed in recent monographs ,…”

“…[36] Herein, we report new or significantly improved syntheses of 1,2-dihaloferrocenes as well as ferrocenecarboxylic acid derivatives obtained by ortho-lithiation. These include the first synthesis of unstable 2-aminoferrocenecarboxylic acid (9), the ferrocene analogue of anthranilic acid. 1,2-Dihaloferrocenes and 2-aminoferrocenecarboxylic acid (9) may be regarded as potential precursors of 1,2-dehydroferrocene.…”

Proton‐ and halogen‐induced cyclizations of 2‐(3‐butenyl)quinazolin‐4(3H)‐ones in the synthesis of pyrrolo[2,1‐b]‐ and pyrrolo[1,2‐а]quinazolinone derivatives

“…To exemplify, the tandem functionalizationcyclization reactions are harnessed in the synthesis of alkoxycarbonyl- [54][55][56], carboxy- [43,57], carbonyl- [58,59], and hydroxy-substituted pyrroloquinazolones [56,60] as well as their fluoro- [61][62][63], sulfo- [64] and boroncontaining derivatives [65]. In view of the active methylene group at position 3 of pyrrolo[2,1-b]-and pyrrolo [1,2-a]quinazolinones, their exo-functionalization is also possible via reactions with electrophiles such as aldehydes [44,66,67], N,N-dialkylformamides [22,68,69], chloroanhydrides [70], and bromine [69,71,72].…”

Targeted Intermediates of Eudesmic Acid: Synthesis and X-ray Investigations

“…Aim of this work is developing effective methods for 3,4,5-trimethoxybenzoic acid, which has reactive carboxylic group and studying their x-ray structure. We can successfully use this synthones in the synthesis of many potential bioactive substances and for introduction of pharmacophoric fragments of eudesmic acid into molecules of different natural [18] and synthetic heterocyclic compounds [19]. These investigations will be presented in our next publications.…”