Abstract: Microbial infection is one of the major concerns for human health in the modern era. Condition is further worsening due to the development of resistance by the microbe against the available drugs. This problem can be overcome by synthesizing novel antimicrobial agents. Isatin is a promising moiety possessing antimicrobial activity. A number of isatin derivatives are present in the market for the treatment of microbial infection. In this review, we have tried to summarize isatin derivatives as antimicrobials, including numerous potent isatin analogs. The reported literature related to the development and application of isatin derivatives have been collected from electronic data bases like Science Direct, Google Scholar, and PubMed by using key words like “design, synthesis and evaluation”, “isatin derivatives,” and “indoldione analogues” and related combinations. It was identified that isatin derivatives play an essential role in drug discovery and development. In recent years, isatin and its derivatives have shown promising antibacterial and antiviral properties. This review aims to provide an overview of the current research on isatin potential applications. Studies have shown that isatin derivatives can effectively fight against various types of microorganisms, such as gram-negative and gram-positive bacteria. They also exhibit lower toxicity and better efficacy than standard antimicrobial agents. Moreover, isatin-based products have the potential to address the rising issue of antimicrobial resistance. The current work attempts to review such innovations, which may lead to the creation of novel therapeutic agents. More research is required to confirm their safety and effectiveness in clinical practice.

Abstract: Thymol is a naturally occurring monoterpenoid phenol, and its derivatives may emerge as eco-friendly materials for the development of chemosensing probes. To prepare a non-toxic chemosensing probe based on thymol moiety for the detection of metal ions. A chemosensor (TPC) based on thymol was afforded by the reaction of thymol and piperidine in methanol. The structure elucidation of TPC was carried out with UV-Vis, 1H-NMR, 13C-NMR, and FT-IR analysis. The chemosensing properties of the synthesized probe were determined with UVvisible spectroscopy, and further, it was exploited for the determination of the concentration of Cu2+ and Pb2+ ions in spiked tap water samples. The toxicity studies of the chemosensing probe were conducted against the plant growth-promoting rhizobacteria (PGPR), i.e., Rhizobium sp., Pseudomonas sp., and Azospirillum sp. The absorption spectrum of TPC showed a band at 277 nm. The presence of Cu2+ and Pb2+ ions induced an increase in the absorption intensity at 277 nm by 2-fold and 1.5-fold, respectively. The binding constant for both TPC-Cu2+ and TPC-Pb2+ was calculated as 1.55 × 105 M-1 and 1.47 × 105 M-1, respectively. The respective limit of detection (LOD) and limit of quantification (LOQ) for Cu2+ were 623.64 × 10-6 mol L-1 and 1889.85 × 10-6 mol L-1. For Pb2+ ions, LOD and LOQ were calculated as 676.70 × 10-6 mol L-1 and 2050.60 × 10-6 mol L-1, respectively. In spiked tap water samples, percent recovery was observed in the range of 80.1 to 81.0 % and 80.1 to 81.9 % for Cu2+ and Pb2+ ions, respectively. Toxicity studies of the synthesized probe inferred that TPC was non-toxic against the tested PGPR at all the tested concentrations. In this work, we have synthesized a thymolbased chemosensor, which has been evaluated as a non-toxic sensor for Pb2+ and Cu2+ ions. background: Owing to important biological and environmental effects of metal ions, it has become obligatory to monitor these in our surroundings. Chemosensors are molecular probes which can detect the specific analytes in the presence of multiple analytes in various media. Thymol is a naturally occurring monoterpenoid phenol having good coordination sites which can be utilized for affording chemosensors via derivatization to compounds like mannich bases, esters, imine derivatives etc. These naturally occurring non-toxic compounds and their derivatives may emerge as eco-friendly materials for development of chemosensing probes . By realizing the importance of biocompatible phenol thymol in the field of sensors, it was anticipated that the chemosensors based on thymol moiety may emerge as non-toxic probes for the detection of metal ions. objective: To synthesize thymol based chemosensor for detection of metal ions. result: The absorption spectrum of TPC showed a band at 277 nm. The presence of Cu2+ and Pb2+ ions induced increase in the absorption intensity at 277 nm by 2-fold and 1.5- fold, respectively. Although, no alteration was observed in the UV-Visible spectra with the addition of other metal ions. The binding constant for both TPC-Cu2+ and TPC-Pb2+ was calculated as 1.55 × 105 M-1 and 1.47 × 105 M-1, respectively. The deduced LOD and LOQ for Cu2+ was 623.64 µM and 1889.85 µM, respectively. For Pb2+ ions, LOD and LOQ was calculated as 676.70 µM and 2050.60 µM, respectively. The binding stoichiometry was estimated as 1:1 by Job’s plot method of continuous variation for both TPC-Cu2+ and TPC-Pb2+ complex. TPC was found reusable up to two cycles. The toxicity study inferred that TPC was non-toxic against all tested PGPR species at all the tested concentrations.

Abstract: The first synthesis of 2-bromogentisyl alcohol, a halogenated compound cytotoxicity to breast cancer cell line, was achieved in four steps. Key steps include (i) formylation of aromatic compound, (ii) bromination, (iii) demethylation and (iv) reduction. Compound 3 was prepared from 4- methoxyphenol (2) in 92% yield in the presence of MgCl2 and Et3N, then intermediate 4 was obtained by bromination of 3 in 78% yield. Subsequently, the direct demethylation of 4 with BBr3 afforded the intermediate 5 in 72% yield. Finally, title compound 1 was prepared by the reduction of 5 using NaBH4 in 87% yield. The overall yield is 45% from 4-methoxyphenol. This method is simple and the reaction conditions are mild.

Abstract: In this present investigation, efficient and general protocols for the synthesis of a series of imidazoles 4(a-p) derivatives have been developed by cyclocondensation of aromatic aldehydes, benzil and ammonium acetate in the existence of efficient [EMIm][BH3CN] ionic liquid catalyst under microwave condition in good to excellent yields (91-97%). The structures of the synthesized compounds have been confirmed by IR and NMR spectra. The significant features of this protocol are an uncomplicated workup process, rate enhancement with high yields, and efficient catalysts. It was concluded that [EMIm][BH3CN] is the finest catalyst under MW heating conditions.

Abstract: Anilinopyrimidines have a wide range of biological activities, including antibacterial, antifungal, and anticancer effects. They have a wide range of uses and opportunities due to their varied experimental preparation and study activities. This creates a lot of interest, experiments and analytical analyses are still being conducted to understand their medicinal chemistry better. According to their effects, which can include antifungal and antibacterial, anticancer or antitumor, and other properties, anilinopyrimidines are categorized in this review. In conclusion, it is critical to base the design of new anilinopyrimidine derivatives and the creation of novel synthesis methodologies on the most recent information discovered through recent research. This review intends to shed light on advancements in the synthetic and biological activity of analogs of anilinopyrimidines.

Abstract: The development of efficient and eco-friendly synthetic processes or techniques for the synthesis of heterocyclic compounds is increasing enormously. Here, an environmentally friendly ionic liquid is used as an efficient catalyst for the synthesis of biologically important dihydropyrano [3,2- c] chromenes. This is because ionic liquids play an important role in green chemistry due to their distinctive properties, easy handling, non-toxicity, increased reaction selectivity, and low solubility. This review focuses on dihydropyrano [3,2-c] chromenes synthesis due to their great importance as natural products, pharmaceuticals, and bioactive molecules. The review summarizes the application of ionic liquids as an effective catalyst for the multicomponent synthesis of dihydropyrano [3,2-c] chromene derivatives by using aromatic aldehydes, 4-hydroxycoumarin, and malononitrile in a green chemical manner.

Abstract: During the process optimization of Lisdexamfetamine dimesylate, two process impurities were observed. Methods: These impurities remained a concern for commercialization and were isolated, on characterization, were found to be H-Lys-ε-Lys-d-amphetamine and other being its regio- isomer H-Lys-α-Lysd- amphetamine. The main target of this study was to synthesize reference compounds for HPLC analysis of these impurities produced in Lisdexamfetamine. Result: To the best of our knowledge, these impurities are not commercially available and no synthetic methods have been reported. Both of these potential impurities were synthesized, and their structures were established by various spectral techniques. Conclusion: Furthermore, herein we also report the synthesis of two process impurities Boc- Lys(Boc)-ε-Lys(α-Boc)-O-Nitrophenol and Boc-Lys(Boc)-α-Lys(ε-Boc)-O-Nitrophenol and their fate for the formation of impurities H-Lys-ε-Lys-d-amphetamine and H-Lys-α-Lys-d-amphetamine.

Abstract: Conductive clay–polymer nanocomposites were prepared via the in situ polymerization of aminoacetophenone and/or aniline monomers (at initial “aminoacetophenone:aniline”) in the presence of polyhydroxy iron cation–modified montmorillonite (MMT-PIC). Fourier transform infrared spectroscopy analysis demonstrated the characteristic bands of the MMT-PIC polymers/copolymers. The morphological properties analyzed and imaged through X-ray diffraction and scanning electron microscopy, respectively, displayed an increasing interlayer distance with the mass loading of PIC and poly(aminoacetophenone-co-aniline) (poly(AAP-co-ANI)), affording intercalated nanocomposites. Energy-dispersive X-ray spectroscopy measurements revealed that the clay experienced a cation exchange of sodium by the PIC, and poly(AAP-co-ANI) was present in large amounts on the nanocomposite surface. The electrical conductivity of the obtained nanocomposites was 5.760 × 10−5 S⋅cm−1. Moreover, the electrochemical behavior of the polymers extracted from the nanocomposites was studied via cyclic voltammetry; the redox processes indicated that the polymerization into activated carbon produced electroactive polymers.

Abstract: A simple and efficient synthesis of pyrrolo[1,2-a]pyrazine using Schiff base formation, intramolecular cyclization (or N-alkylation), and Pictet–Spengler type reaction (hetero-aromatisation) has been developed. In this chemistry, metal-free, cost and time-effective processes have been highlighted to afford the complex nitrogenous scaffold using simple starting materials.

Abstract: Amphiphilic tri-arm star-shaped copolymers, poly(ethylene oxide)-b-poly(ε-caprolactone) PEO3-b-PCL3, with different poly (ε-caprolactone) (PCL) molecular weights were successfully synthesized by ring-opening polymerization (ROP). Firstly, the tri-arm star-shaped PEO3 was prepared by ROP of trimethylolpropane and ethylene oxide (EO). The ring-opening polymerization (ROP) of ε- caprolactone (CL) was initiated using the tri-arm star-shaped PEO3 with the hydroxyl group as macroinitiator and Sn(Oct)2 as a catalyst. Amphiphilic tri-arm star-shaped copolymers PEO3-b-PCL3 were obtained. By changing the ratio of monomer and macroinitiator, a series of PEO3-b-PCL3 were prepared with a well-defined structure, molecular weight control, and narrow molecular weight distribution. The expected intermediates and final products were confirmed by 1H NMR and Gel Permeation Chromatography (GPC) analyses. In addition, the sizes and morphologies of the obtained micelles with different PCL segment lengths were investigated with dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. It was found that the self-assembly morphologies were spherical micelle in aqueous solution.