scholarly journals An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

2011 ◽  
Vol 7 ◽  
pp. 442-495 ◽  
Author(s):  
Marcus Baumann ◽  
Ian R Baxendale ◽  
Steven V Ley ◽  
Nikzad Nikbin
Keyword(s):  
Membered Ring ◽  
Comprehensive Overview ◽  
Vast Number ◽  
Drug Compounds ◽  
Patent Literature ◽  
Synthetic Routes

This review presents a comprehensive overview on selected synthetic routes towards commercial drug compounds as published in both journal and patent literature. Owing to the vast number of potential structures, we have concentrated only on those drugs containing five-membered heterocycles and focused principally on the assembly of the heterocyclic core. In order to target the most representative chemical entities the examples discussed have been selected from the top 200 best selling drugs of recent years.

Tropone (cyclohepta-2,4,6-trienone) derivatives related to biphenylene. 5H-Benzo[3,4]cyclobuta[1,2]cyclohepten-5-one, 6H-Benzo[3,4]cyclobuta[1,2]cyclohepten-6-one and 7H-Benzo[3,4]cyclobuta[1,2]cyclohepten-7-one

1978 ◽  
Vol 31 (7) ◽  
pp. 1585 ◽  
Author(s):  
L Lombardo ◽  
RK McCulloch ◽  
D Wege
Keyword(s):  
Membered Ring ◽  
Crystalline Solid ◽  
Bond System ◽  
Synthetic Routes ◽  
Benzenoid Ring

Synthetic routes to 5H-benzo[3,4]cyclobuta[1,2]cyclohepten-5-one (6), 6H-benzo[3,4]cyclobuta-[1,2]cyclohepten-6-one (5) and 7H- benzo[3,4]cyclobuta[1,2]cyclohepten-7-one (7), which are analogues of biphenylene in which one benzenoid ring has been replaced by the cyclohepta-2,4,6-trienone (tropone) ring, have been investigated. The tropone (5) was obtained as a stable, crystalline solid and 1H n.m.r, evidence suggests that (5) has a more localized π-bond system in the seven-membered ring than tropone itself. The reactive tropone derivative (7) was generated in solution, and trapped as a 6πs+4πs cycloadduct with cyclopentadiene.

scholarly journals Features of the synthesis and biological evaluation of 3-(carboxyphenyl)chromones

2020 ◽  
Vol 15 (2) ◽  
pp. 3-12
Author(s):  
Olga Shablykina ◽  
Viktoriia Moskvina ◽  
Volodymyr Khilya
Keyword(s):  
Biological Activity ◽  
Biological Evaluation ◽  
Therapeutic Agents ◽  
New Drugs ◽  
Pharmacological Activities ◽  
Chromone Derivatives ◽  
Methods Of Synthesis ◽  
Patent Literature ◽  
Synthetic Routes ◽  
Synthesis And Biological Evaluation

Flavonoids and their derivatives have historically been a source of therapeutic agents. Every year, more and more data is published on new flavonoid compounds, both synthetic and isolated from natural sources, and their innumerable physiological and pharmacological activities. This review presents synthetic routes towards 3-(carboxyphenyl)chromones and evaluation of their biological activity as published in both journal and patent literature. We have focused specifically on the 3-(carboxyphenyl)chromones, because while methods of synthesis and biological activity of 2(3)-substituted and 2,3-disubstituted chromones are well studied, literature data on isoflavones containing a carboxyl, ester, or amide group in ring B is scarce and fragmentary. The presented generalization of synthetic strategies and biological activity of 3-(carboxyphenyl)chromone derivatives demonstrates that this class of compounds can be targeted for discovery of new drugs and can be readily prepared owing to recent advances in synthetic organic and medicinal chemistry.

A relative extrusibility scale and its application to the thermal fragmentation patterns of 5-membered ring diazenes

1981 ◽  
Vol 59 (3) ◽  
pp. 491-505 ◽  
Author(s):  
Anthony James Paine ◽  
John Warkentin
Keyword(s):  
Functional Group ◽  
Heat Of Formation ◽  
Membered Ring ◽  
Molecular Fragment ◽  
Thermodynamic Cycles ◽  
Thermal Fragmentation ◽  
Heats Of Reaction ◽  
Synthetic Routes ◽  
Fragmentation Patterns ◽  
First Time

Extrusion of a stable molecular fragment (like N2, CO2, SO2, CO, etc.) is a common chemical process. Using thermodynamic additivity concepts, group values, and heat of formation data, a Relative Extrusibility Scale (ΔHex0) has been defined for these fragmentations:[Formula: see text]Twenty-four such extrusions spanning 150 kcal mol−1 have been compiled. Typical values include N2 (−42.0), CO2 (−2.6), HCN (13.8), CO (15.4), H2CO (18.3), C2H4 (32.2), and 1CH2 (109). Among other theoretical and mechanistic applications, this list should be useful when designing synthetic routes involving extrusion reactions.In a particularly effective illustration of the usefulness of the scale, it rationalizes, for the first time, the variety of product types obtained from thermolyses of 14 different kinds of 5-membered ring diazenes. Heat of formation data on most of these compounds do not exist and they contain such sufficiently complicated functional group arrangements that most of the thermodynamic group equivalents are also unknown. This problem can be circumvented by thermodynamic cycles based on the Relative Extrusibility Scale, suitable models, and interfragment resonance corrections. Within an error framework of less than ± 5 kcal mol−1, enthalpy estimates are sufficiently accurate to give heats of reaction capable of predicting which of the potential fragmentation routes actually occur. Formation of a 3-membered ring must be exothermic by at least 30 kcal mol−1 to contribute to the products, but 3-piece fragmentation and 1,3-dipolar cycloreversion will contribute to the observed products when the process is either thermoneutral or exothermic. The unimportance of entropy is also discussed.

Organometallic complexes of neodymium: an overview of synthetic methodologies based on coordinating elements

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Adeena Asif ◽  
Rana Yasir Nadeem ◽  
Muhammad Adnan Iqbal ◽  
Shamsa Bibi ◽  
Muhammad Irfan
Keyword(s):  
Research Work ◽  
Metal Chloride ◽  
Organometallic Complexes ◽  
Comprehensive Overview ◽  
Synthetic Routes ◽  
Magnetic Applications ◽  
Synthetic Methodologies

Abstract Organometallic complexes of neodymium have unique coordinating ability to form both micro and macromolecules as well as metal-based polymers. These complexes have been reported in different fields and play a tremendous role in luminescence, catalytic, biological and magnetic applications. So, the current study will comprise all possible routes for the synthesis of organometallic complexes of neodymium. Neodymium complexes have been synthesized of single, double, triple and tetra linkages with H, C, N, O as well as S, B, and X. The detailed synthetic routes have been classified into four categories but in brief, neodymium forms complexes by reacting metal chloride, nitrate or oxide (hydrated or dehydrated) as precursor along with appropriate ligand. Most applied solvents for neodymium complexes were Toluene and THF. These complexes required a range of temperature based on the nature of complexes as well as linkages. The authors have surveyed the research work published through 2011–2020 and provide a comprehensive overview to understand the synthetic routes of organometallic complexes of neodymium.

Synthesis and Use of Reactive Molecular Precursors for the Preparation of Carbon Nanomaterials

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Bjoern Schulte ◽  
Stephen Schrettl ◽  
Holger Frauenrath
Keyword(s):  
Carbon Nanostructures ◽  
Carbon Nanomaterials ◽  
Coupling Reactions ◽  
Carbonaceous Matter ◽  
Comprehensive Overview ◽  
Chemical Functionalization ◽  
Molecular Precursors ◽  
Synthetic Routes ◽  
Forms Of Carbon ◽  
New Generation

AbstractThe use of reactive molecular carbon precursors is required if the preparation of carbon nanostructures and nanomaterials is to be achieved under conditions that are sufficiently benign to control their nanoscopic morphology and tailor their chemical functionalization. Recently, oligoyne precursors have been explored for this purpose, as they are sufficiently stable to be available in tangible quantities but readily rearrange in reactions that yield other forms of carbon. In this chapter, we briefly discuss available synthetic routes toward higher oligoynes that mostly rely on transition metal-mediated coupling reactions. Thereafter, a comprehensive overview of the use of oligoyne derivatives as precursors for carbon nanostructures and nanomaterials is given. While the non-templated conversion of simple oligoynes into carbonaceous matter exemplifies their potential as metastable carbon precursors, the more recent attempts to use functionalized oligoynes in host–guest complexes, self-assembled aggregates, thin films, colloids or other types of supramolecular structures have paved the way toward a new generation of carbon nanomaterials with predictable nanoscopic morphology and chemical functionalization.

scholarly journals An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

2013 ◽  
Vol 9 ◽  
pp. 2265-2319 ◽  
Author(s):  
Marcus Baumann ◽  
Ian R Baxendale
Keyword(s):  
Pharmaceutical Compounds ◽  
Heterocyclic Ring ◽  
Reference Source ◽  
Scientific Journals ◽  
Drug Molecules ◽  
Patent Literature ◽  
Synthetic Routes

This review which is the second in this series summarises the most common synthetic routes as applied to the preparation of many modern pharmaceutical compounds categorised as containing a six-membered heterocyclic ring. The reported examples are based on the top retailing drug molecules combining synthetic information from both scientific journals and the wider patent literature. It is hoped that this compilation, in combination with the previously published review on five-membered rings, will form a comprehensive foundation and reference source for individuals interested in medicinal, synthetic and preparative chemistry.

scholarly journals An overview of metal-free synthetic routes to isoxazoles: the privileged scaffold

RSC Advances ◽  
2021 ◽  
Vol 11 (52) ◽  
pp. 32680-32705
Author(s):  
Soumyadip Das ◽  
Kaushik Chanda
Keyword(s):  
Review Article ◽  
Comprehensive Overview ◽  
Metal Free ◽  
Privileged Scaffold ◽  
Synthetic Routes ◽  
Heterocyclic Moiety

Isoxazole, a five-membered heterocyclic moiety commonly found in many commercially available drugs. This review article presents a comprehensive overview on metal-free synthetic routes for the synthesis of isoxazoles with significant bioactivities.

A mild route to α-alkoxyacetylenes mediated by lewis acids and synthetic routes to 10-, 11-, and 12-membered ring enediyne carbocycles

2000 ◽  
Vol 40 (3-4) ◽  
pp. 241-253 ◽  
Author(s):  
Bogdan M. Comanita ◽  
Matthew A. Heuft ◽  
Tanya Rietveld ◽  
Alex G. Fallis
Keyword(s):  
Lewis Acids ◽  
Membered Ring ◽  
Synthetic Routes

scholarly journals Chemical syntheses and salient features of azulene-containing homo- and copolymers

2021 ◽  
Vol 17 ◽  
pp. 2164-2185
Author(s):  
Vijayendra S Shetti
Keyword(s):  
Field Effect Transistors ◽  
Functional Polymers ◽  
Ring Structure ◽  
Review Article ◽  
Membered Ring ◽  
Organic Field Effect Transistors ◽  
Comprehensive Overview ◽  
Polymer Backbone ◽  
Bright Color ◽  
Homo Lumo

Azulene is a non-alternant, aromatic hydrocarbon with many exciting characteristics such as having a dipole moment, bright color, stimuli responsiveness, anti-Kasha photophysics, and a small HOMO–LUMO gap when compared to its isomer, naphthalene. These properties make azulene-containing polymers an intriguing entity in the field of functional polymers, especially for organic electronic applications like organic field-effect transistors (OFET) and photovoltaic (PV) cells. Since azulene has a fused five and seven-membered ring structure, it can be incorporated onto the polymer backbone through either of these rings or by involving both the rings. These azulene-connection patterns can influence the properties of the resulting polymers and the chemical synthesis in comparison to the electrochemical synthesis can be advantageous in obtaining desired patterns of substitution. Hence, this review article presents a comprehensive overview of the developments that have taken place in the last three decades in the field of chemical syntheses of azulene-containing homo- and copolymers, including brief descriptions of their key properties.

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