Xylochemical Synthesis and Biological Evaluation of Shancigusin C and Bletistrin G

The biological activities of shancigusin C (1) and bletistrin G (2), natural products isolated from orchids, are reported along with their first total syntheses. The total synthesis of shancigusin C (1) was conducted by employing the Perkin reaction to forge the central stilbene core, whereas the synthesis of bletistrin G (2) was achieved by the Wittig olefination followed by several regioselective aromatic substitution reactions. Both syntheses were completed by applying only renewable starting materials according to the principles of xylochemistry. The cytotoxic properties of shancigusin C (1) and bletistrin G (2) against tumor cells suggest suitability as a starting point for further structural variation.

Synthesis, Characterization, and Applications of Coumarin Derivatives: A Short Review

Coumarin and its derivatives represent one of the most active curriculums of compound possessing a broad spectrum of biological activity along with other applications such as insecticide and fragrance. There are various methodologies developed for the synthesis of coumarins. Classical routes to coumarins include Pechmann condensation, Knoevenagel condensation, Perkin reaction, and Wittig condensation reactions. Researchers have carried out adjustments and improvements to increase the efficacy and overcome the limitations from the classical route. In this review outline, coumarin derivatives were characterized by using FTIR and Hydrogen NMR spectroscopy. This review paper focuses on various synthesis and characterization techniques to analyze coumarin derivatives and their potential application in various fields.

A Review on Synthesis and Pharmacological Activity of Coumarins and Their Analogs

Background: Coumarins were reported to possess antimicrobial, antiinflammatory, antiplasmodial, antimalarial, and enzyme inhibitory properties. Furthermore, coumarins are a type of vitamin K antagonists. Coumarins had been first organized through perkin reaction; besides Knoevenagel condensation was mentioned as a critical synthetic approach for the synthesis of 3-substituted coumarins. Moreover, Pechmann, Reformatasky and Witting reactions were stated for the preparation of coumarins. Methods: We undertook a structured search of the method of preparation, the chemical reactivity and biological properties that are associated with coumarins and their analogous. Results: Coumarins display a wide range of Src Kinase and cholinesterase inhibitor activities and application of coumarins as antidiabetic, antipsychotic and antiproliferative agents has been addressed. Other properties of coumarins such as their role in antitumor, anticancer, and as antioxidants have also been reviewed. Conclusion: This review concluded that coumarin ring was mixed with other rings, a synergistic effect for each of the ring in their biological activities was obtained, such compounds were exploited to improve various important molecules which provide scaffolds for drug improvement. These compounds were used to broaden a special molecule that gives scaffolds for drug improvement.

Synthesis of Cinnamic Acid Based on Perkin Reaction Using Sonochemical Method and Its Potential as Photoprotective Agent

<p>Cinnamic acid plays a vital role in the synthesis of other important compounds and as a precursor for the synthesis of commercial cinnamon esters used in perfumery, cosmetics, and pharmaceutical industries. The aim of this research is to synthesize cinnamic acid using sonochemical methods. Cinnamic acid was synthesized using Perkin reaction by reacting 0.05 mole of benzaldehyde with 0.073 mole of acetic acid anhydride and 0.03 mole of sodium acetate as a catalyst in the Erlenmeyer flask and then the mixture was put in a sonicator for 60 minutes at 70 ^oC. The synthesized compound was tested organoleptic properties, and the melting point was measured. The chemical structure was elucidated using FT-IR, H-NMR, and ¹³C-NMR. The photoprotective activity was examined from its antioxidant and SPF values. The synthesized compound was found in the form of a shiny white fine crystal which had distinctive odor with a yield of 4.98% and the melting point was found at 133^oC. In the structure elucidation using FT-IR (the aromatic ring absorption at the wave number 1580 cm^-1 -1600 cm^-1. The wave number 1625 cm^-1is an aromatic conjugated alkene group, while wave number 1689.4 cm^-1is a carbonyl group. The wave number 2500 cm^-1– 3250 cm^-1is an OH carboxylic acid group) , H-NMR (7.410 (<em>m</em>, 5H, Ar-H); 7.425(<em>t</em>, 1H); 7.572 (<em>d</em>, 1H); 8.057 (d, 1H,C=CH) and ¹³C-NMR (129.309 ppm; 130.998 ppm; 134.58 ppm; 170.017 ppm) showed that when compared with the standard compound as the reference, the synthesized compound was confirmed to be cinnamic acid. The antioxidant activity test showed that at the concentration of 20 ppm the synthesized compound was able to reduce free radicals by 46.69%. This finding showed that the synthesized compound had antioxidant activity.</p>

A carboxyfunctionalized (24)-1,6-pyrenophane-tetraene by glyoxylic Perkin condensation

Without employing high dilution conditions, the fourfold 2+2 Perkin reaction of 1,6-pyrenylene-diglyoxylic acid with its reduction product 1,6-pyrenylene-diacetic acid yields the corresponding tetrameric conjugated macrocycle in 25% overall yield after in-situ esterification. The macrocycle adopts a square fourfold symmetry in the crystal, with near-vertical pyrene walls that alternatingly tilt upwards and downwards.

Crystal structure of methyl (E)-4-[2-(8-hydroxyquinolin-2-yl)vinyl]benzoate

The title compound, C19H15NO3, was synthesized by a Perkin reaction of 2-methyl-8-hydroxyquinoline and 4-formyl-2-methylbenzoate in acetic anhydride under a nitrogen atmosphere. The molecule has anEconformation about the C=C bond, and the quinoline ring system and the benzene ring are inclined to one another by 29.22 (7)°. There is an intramolecular O—H...N hydrogen bond in the 8-hydroxyquinoline moiety. In the crystal, molecules are linked by pairs of O—H...O hydrogen bonds, forming inversion dimers with anR22(28) ring motif. The dimers are linked by C—H...O hydrogen bonds and C—H...π interactions, forming sheets parallel to plane (10-1).