2.5. Ionic Liquids Presented in This Review 2020 3. Cyclocondensation Reactions 2020 4. Synthesis of Three-Membered Heterocycles 2022 4.1. Aziridines 2022 5. Synthesis of Five-Membered Heterocycles 2022 5.1. Pyrroles 2022 5.2. Furans 2022 5.3. Thiophenes 2023 5.4. Pyrazoles 2024 5.5. Imidazoles 2025 5.6. Isoxazoles 2027 5.7. Oxazoles, Oxazolines, and Oxazolidinones 2027 5.8. Thiazoles and Thiazolidinones 2028 6. Synthesis of Six-Membered Heterocycles 2030 6.1. Pyridines 2030 6.2. Quinolines 2031 6.3. Acridines 2033 6.4. Pyrans 2033 6.5. Flavones 2035 6.6. Pyrimidines and Pyrimidinones 2035 6.7. Quinazolines 2037 6.8. -Carbolines 2038 6.9. Dioxanes 2039 6.10. Oxazines 2039 6.11. Benzothiazines 2040 6.12. Triazines 2040 7. Synthesis of Seven-Membered Heterocycles: Diazepines 2041

Ionic liquids in heterocyclic synthesis.

Hypothermic and antipyretic effects of 3-methyl- and 3-phenyl-5-hydroxy-5-trichloromethyl-4,5-dihydro-1H-pyrazole-1-carboxyamides in mice

Synthesis of new N-phenylpyrazole derivatives with potent antimicrobial activity

https://www.kau.edu.sa/Files/961/Researches/61563_32502.pdf

Synthesis and biological evaluation of new 3-trifluoromethylpyrazolesulfonyl-urea and thiourea derivatives as antidiabetic and antimicrobial agents

Update 1 of: Ionic liquids in heterocyclic synthesis.

Haloacetylated enol ethers: 12 [18]. Regiospecific synthesis and structural determination of stable 5-hydroxy-1H-pyrazolines

Trifluoromethyl-containing pyrazolinyl ( p -tolyl) sulfones: The synthesis and structure of promising antimicrobial agents

Polymorphs have been widely studied since different crystalline phases of the same compound may have distinct properties. Macromolecules are an area of major study with just a few polymorphs reported. This investigation presents the first case of polymorphism in a [2]rotaxane molecule. This rotaxane contains a succinamide station bearing nonsymmetric stoppers and a tetralactam macrocycle. A different polymorphic phase is achieved by varying the crystallization solvent. These polymorphs presented relevant differences at the molecular level and were classified as conformational polymorphs. At the supramolecular level, polymorph I is −21 kcal mol–1 more stable than polymorph II. Crystallization mechanisms to assess the stages of the crystallization process were proposed. Similar stabilization of the first nuclei formed was observed to be responsible for the possibility of both forms to coexist. The large differences observed between the polymorphs were not significantly reflected in the types and contributio...

Polymorphism in a Rotaxane Molecule: Intra- and Intermolecular Understanding

Crystallization Mechanisms Applied to Understand the Crystal Formation of Rotaxanes

A systematic investigation to assess the degree of similarity between polymorphs was carried out. A similarity indices (IX) approach was applied in ten series of polymorphs with different characteristics and number of molecules in the asymmetric unit. Geometric (ID), contact area (IC), and stabilization energy (IG) parameters were used. It was possible to situate each comparison in different regions of similarity within the polymorphism phenomenon and determine the boundaries between quasi-isostructural polymorphs and polymorphs of low similarity. The multiparameter IDCG index was used as a robust tool to determine the total similarity within the polymorphism phenomenon. The highest contribution of the stabilization energy parameter (45%) toward the final value of similarity (IDCG) was observed, followed by the contact area index (32%). The geometric index contributed approximately 23% to the final value of IDCG. This information reinforces the importance of the contact area and stabilization energy in assessing the degree of similarity between crystalline structures. A new descriptor (IQ) based on the comparison of the energetic contribution of intermolecular interaction types present in each crystal structure is presented. IQ can be a versatile tool and applicable even for systems that do not share any similarity.

https://pubs.acs.org/doi/pdf/10.1021/acsomega.8b03660

Manfredo Hoerner

Papers

Haloacetylated enol ethers: 12 [18]. Regiospecific synthesis and structural determination of stable 5-hydroxy-1H-pyrazolines

Trifluoromethyl-containing pyrazolinyl ( p -tolyl) sulfones: The synthesis and structure of promising antimicrobial agents

Polymorphism in a Rotaxane Molecule: Intra- and Intermolecular Understanding

Crystallization Mechanisms Applied to Understand the Crystal Formation of Rotaxanes

Supramolecular Similarity in Polymorphs: Use of Similarity Indices (IX)