Current Organic Synthesis - Volume 20, Issue 4, 2023

This paper describes indigo chemistry and its brief scientific history beginning with the first characterization and chemical synthesis of indigo via various precursors such as isatin, cinnamic acid, 2-nitrobenzaldehyde, anthranilic acid, N-phenylglycine, aniline, and indole. Furthermore, alternative methods such as eco-friendly microbial synthesis of indigo using a variety of enzymes are reported: Cytochrome P450 monooxygenases, flavin-containing monooxygenases, and unspecific peroxygenases. Subsequently, the application of indigo in the denim industry, reduction methods (chemical, electrochemical, enzymatic and catalytic) and dyeing methods (all parameters in dyeing, ring dye) are discussed. In addition, the main reason for the use of indigo in the denim industry is briefly explained.

Background: In this paper, a novel catalyst is synthesized and characterized by immobilizing copper onto imidazopyridine-modified superparamagnetic iron oxide nanoparticles (SPION). Methods: The catalyst is characterized by several methods, including TEM, SEM, ICP, DLS, and VSM. The catalytic activity of the catalyst is evaluated in the synthesis of thiosolfunamide. The synthesized catalyst showed very good activity in the mentioned reaction and performance for synthesizing the desired products in high isolated yields. Results: For the synthesis of the products, sequential transformations enable the facile synthesis of complex target molecules from simple building blocks in a single preparative step. Conclusion: The reaction can be performed with a high yield using water and ethanol as the reaction green solvent using terminal alkynes and sulfonyl azides as starting materials. The reusability of the catalyst was tested, and the results proved high reusability of the catalyst.

Heterocyclic compounds are a class of compounds that is deeply intertwined with biological processes and is found in about 90% of commercially available medicines. They serve a critical function in medicinal chemistry and are focused in the field of medication development for their intensive research due to their broad variety of biological effects because of their intriguing molecular architecture, such as indoles are good candidates for drug development. It is a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered pyrrole ring with several pharmacophores that yield a library of different lead compounds. Human cancer cells have been demonstrated to be inhibited by indoles in the development of new anticancer medicines. This is the first comprehensive review to focus on current methodologies for incorporating indole moiety, with their mechanistic targets as anticancer drugs, in order to shed light on the logical development of indole-based anticancer treatment options with high efficacy. This compiled data may serve as a benchmark for modifying existing ligands in order to design novel potent molecules through excellent yield synthesis techniques.

Fatty acids derived from oils and fats of different plant and animal resources are considered one of the most valuable renewable precursors of the synthetic chemical and pharmaceutical industries. On the other hand, heterocyclic compounds are well known nowadays by their constitution of many commercialized drugs due to their unique biological activities. Combination between fatty acids and heterocyclic compounds has made important advances in the construction of valuable biologically relevant molecules in pharmaceutical industry. This review casts light on the synthetic pathways for construction of the fatty acid-heterocycle hybrid up to date in a simple classification and arranged manner.

Background: Benzimidazoles have a wide range of synthetic applications in medicinal chemistry and biological activities like anti-tumor/anti-proliferative activities etc. Moreover, different heterocyclic moieties attached to the benzimidazole ring improved anticancer activities. Methods: All the chemicals were purchased from Aldrich Chemical Company, are of AR grade and used as received. Microanalytical data (C, H, and N) were analyzed on a Carlo Erba model 1108 analyzer. Melting points were measured by the Kofler apparatus and were uncorrected. Spectroscopic data were obtained using the following instruments: Fourier transform infrared spectra (KBr discs, 4000-400 cm^-1) by Shimadzu IR-408 Perkin Elmer 1800 instrument; ¹H NMR and ¹³C NMR spectra by JEOL Resonance Inc. Tokyo, Japan, JNM-ECZ400S/L1 using DMSO-d6 as a solvent containing TMS as the internal standard. Chemical shifts (δ) are reported in parts per million (ppm), and coupling constants (J) are reported in Hertz (Hz). Results: We chose sulfosalicylic acid as a promoter for forming benzimidazole-acrylonitrile derivatives, which is an eco-friendly reaction, and we applied a series of synthesized compounds 3a-g in nematicidal activity. The results indicate that the concentrations of all treatments significantly kill M. incognita. Conclusion: This model reaction procedure provides a better method for preparing benzimidazoleacrylonitrile, which is superior to other methods. This protocol simplifies handling model reactions with mild reaction conditions, a short time period, a simple set-up, a fast reaction rate, and so on.

Objective: Vanillin/Vitamin B1 (Thiamine) supported Fe3O4@Sio2 nanoparticles (Fe3O4 @SP@VT) were synthesized and thoroughly analyzed, and were used for the green and efficient synthesis of chromenes using the multicomponent reaction of aldehyde, malononitrile and 4-hydroxy coumarin, as well as the multicomponent reaction of aldehyde, α-naphthol or β–naphthol and 4-hydroxy coumarin. Methods: The reaction was performed under grinding conditions, and at the end of the reaction, the catalyst was separated in the presence of a strong magnet and can be recovered 10 times. Results: The advantages of this method are high purity of products, short times, higher yield, easy separation and cheap raw materials. Conclusion: We have developed Fe3O4@SP@VT catalyzed multicomponent synthesis of aminobenzochromenes using the reaction of benzaldehyde, malononitrile and naphthol and multicomponent synthesis of benzopyranochromenes using benzaldehyde, 4-hydroxycoumarin and β-naphthol under grind technique.

Objective: Misoprostol is a synthetic prostaglandin that is related structurally to naturally occurring prostaglandin (PG), and it has been acknowledged as an effective inhibitor of gastric acid secretion when administered intravenously. Methods: In the present study, the novel application of 1,8-Diazabicyclo[5.4.0]undec-7-ene, a cyclic unsaturated amine [DBU] for the conversion of A-type Misoprostol (A-MP) to B-type Misoprostol (B-MP) via intramolecular isomerization. Results: The intramolecular isomerization process was successfully applied for the separation of enantio-pure isomers with no impurities using DBU. Conclusion: The chemical structures of A-MP and B-MP were confirmed using spectral analyses of 1H-NMR, 13C-NMR and Mass spectroscopy.