Efficient synthesis of tetrasubstituted imidazoles using Bi(III)Br.
Journal name: World Journal of Pharmaceutical Research
Original article title: Simple and efficient protocol for the synthesis of 1, 2, 4, 5-tetrasubstituted imidazoles promoted by bismuth (iii) bromide
The WJPR includes peer-reviewed publications such as scientific research papers, reports, review articles, company news, thesis reports and case studies in areas of Biology, Pharmaceutical industries and Chemical technology while incorporating ancient fields of knowledge such combining Ayurveda with scientific data.
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Venkata Reddy H., Rajendraprasad K. J., Shekar H. S. and Manjula Krishnappa
World Journal of Pharmaceutical Research:
(An ISO 9001:2015 Certified International Journal)
Full text available for: Simple and efficient protocol for the synthesis of 1, 2, 4, 5-tetrasubstituted imidazoles promoted by bismuth (iii) bromide
Source type: An International Peer Reviewed Journal for Pharmaceutical and Medical and Scientific Research
Copyright (license): WJPR: All rights reserved
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Summary of article contents:
Introduction
The synthesis of 1,2,4,5-tetrasubstituted imidazoles has garnered significant interest due to their extensive biological and pharmaceutical properties. These compounds serve as essential substructures in a wide range of active pharmaceutical ingredients, encompassing antiallergic, analgesic, antifungal, antibacterial, and anti-inflammatory agents. The exploration of efficient and environmentally friendly synthetic methodologies is pivotal for advancing the development of these biologically important molecules. This research presents a novel protocol employing Bismuth (III) bromide as a promoter for the synthesis of these imidazole derivatives using easily accessible reactants and conditions that minimize toxicity and environmental impact.
Efficient Synthesis Using Bismuth (III) Bromide
One of the critical advancements of this work is the introduction of Bismuth (III) bromide (BiBr3) as a catalyst for synthesizing 1,2,4,5-tetrasubstituted imidazoles via a four-component reaction. This reaction involves the condensation of 1,2-diketones with aryl aldehydes, aryl amines, and ammonium acetate in an ethanolic medium at 80°C. The use of BiBr3 allows for a high yield of products within a relatively short reaction time of 30 minutes to 3.5 hours, making this method both time-efficient and practical. The study highlights how BiBr3's low toxicity and effectiveness as a catalyst make it a favorable choice compared to other examples in the literature that utilize more costly or hazardous reagents.
Optimization of Reaction Conditions
The optimization of reaction conditions is fundamental to enhancing yield and efficiency in synthesis. Initial trials without a catalyst failed to yield desired compounds, emphasizing the necessity of appropriate catalytic conditions. Subsequent experiments demonstrated that varying the concentration of BiBr3 and the solvent significantly affected yield outcomes. For instance, a 5 mol % of BiBr3 in ethanol achieved an 84% yield, while reactions conducted in methanol and acetonitrile showed lesser yields, indicating ethanol's superior role in this reaction scheme. These findings underline the importance of solvent selection and catalyst optimization in facilitating improved synthesis protocols.
Characterization and Yield Assessment
Characterization of the synthesized compounds was performed through various analytical techniques, including IR spectroscopy, NMR spectroscopy, and LC-MS. This comprehensive analysis ensured that the products were accurately identified and confirmed their efficacy. The study reports that the resulting imidazole derivatives exhibited good to excellent yields across multiple substrate variations, thus establishing the broad applicability of the protocol. The research provides a table of synthesized compounds along with their respective yields, affirmatively showing the reproducibility and efficiency of the reaction conditions.
Conclusion
In summary, this research successfully reports a simple and efficient protocol for synthesizing 1,2,4,5-tetrasubstituted imidazoles using Bismuth (III) bromide as a catalyst. The method not only yields products with high efficiency but also adheres to principles of green chemistry by employing low-toxicity reagents and a relatively straightforward work-up procedure. The demonstrated capabilities of this synthetic approach contribute valuable insights to the field of medicinal chemistry and encourage further exploration of bismuth compounds in organic synthesis. The findings pave the way for developing new therapeutic candidates and highlight the potential for environmentally friendly practices in chemical synthesis.
FAQ section (important questions/answers):
What is the main objective of the study conducted by Manjula et al.?
The study aimed to develop a simple and efficient protocol for synthesizing 1,2,4,5-tetrasubstituted imidazoles using Bismuth (III) bromide as a promoter, optimizing reaction conditions and improving yield.
What are the main components used in the synthesis of imidazoles?
The synthesis involves a four-component reaction using 1,2-diketones, aryl aldehydes, aryl amines, and ammonium acetate in the presence of Bismuth (III) bromide catalyst and ethanol as the solvent.
What advantages does BiBr3 provide in the synthetic process?
Bismuth (III) bromide offers several advantages as a catalyst, including low toxicity, good stability, and effectiveness in organic reactions, leading to high yields in a reduced reaction time.
How were the reactions monitored during the synthesis process?
The reactions were monitored using Thin Layer Chromatography (TLC) with a solvent mixture of petroleum ether and ethyl acetate to track the formation of the desired compounds.
What were the results of optimizing catalyst amounts in the study?
The study observed that using 5 mol% BiBr3 at 80°C for 3.5 hours yielded an 84% yield of the desired products, demonstrating the protocol's efficiency in varying conditions.
What was concluded about the new synthesis protocol developed by the authors?
The authors concluded that the developed protocol offers good to excellent yields, simple work-up procedures, and utilizes an environmentally friendly and inexpensive catalyst, making it advantageous for synthesizing imidazoles.
Glossary definitions and references:
Scientific and Ayurvedic Glossary list for “Efficient synthesis of tetrasubstituted imidazoles using Bi(III)Br.”. This list explains important keywords that occur in this article and links it to the glossary for a better understanding of that concept in the context of Ayurveda and other topics.
1) Table:
In academic and research contexts, a table organizes data succinctly for comparison and presentation. The use of tables, like Table I and II in the document, allows readers to easily visualize results, optimization conditions, and product yields during the synthesis of compounds. Tables enhance clarity and facilitate understanding by summarizing key information.
2) India:
India is a country in South Asia known for its rich diversity in culture, language, and scientific advancements. The research conducted in India, particularly at Bharathiar University and Visveswarapura Institute of Pharmaceutical Sciences, reflects the nation's growing contribution to global scientific developments, especially in the field of pharmaceuticals and organic synthesis.
3) Tamilnadu (Tamil-nadu):
Tamilnadu is a state in southern India renowned for its contributions to education, culture, and industries. It houses Bharathiar University, which plays a crucial role in scientific research, fostering innovation in various fields including chemistry and pharmaceuticals. The state's infrastructure supports academic pursuits that lead to advancements in health and medicine.
4) Toxicity:
In the context of chemistry and pharmaceuticals, toxicity refers to the degree to which a substance can harm living organisms. The synthesis protocol discussed emphasizes the low toxicity of Bismuth (III) bromide compared to other compounds, underlining the importance of using less toxic catalysts in minimizing environmental and health risks in drug development.
5) Science (Scientific):
Science is the systematic study of the natural world through observation and experimentation. The research presented focuses on synthesizing imidazoles, showcasing the application of scientific principles in developing new compounds. Scientific inquiry drives pharmaceutical advancements, contributing to improved treatments and understanding of biological interactions.
6) Pharmacological:
Pharmacological refers to the study of drug action and the effects of drugs on biological systems. The document discusses pharmacologically active compounds, specifically imidazoles, highlighting their relevance in drug development for conditions like antibacterial infections and inflammation, thus illustrating the role of pharmaceutical chemistry in healthcare.
7) Transformation (Transform, Transforming):
In chemistry, transformation describes the process of changing one chemical substance into another. The synthesis of 1,2,4,5-tetrasubstituted imidazoles involves various transformations mediated by Bismuth (III) bromide. Understanding these transformations is vital for developing efficient synthetic methods and improving yield in pharmaceutical applications.
8) Antibiotic (Antibacterial):
Antibacterial agents are substances that inhibit bacterial growth or kill bacteria. The document underscores the importance of imidazole derivatives, which possess antibacterial properties, in designing new therapeutic agents. The synthesis of such compounds is critical in combating bacterial infections, thereby contributing significantly to public health.
9) Tuberculosis:
Tuberculosis (TB) is a serious infectious disease typically affecting the lungs, caused by the bacterium Mycobacterium tuberculosis. The research highlights the potential of synthesized imidazole derivatives as therapeutic candidates against TB, reflecting the ongoing need for new treatments in the fight against this global health issue.
10) Purification:
Purification refers to the process of isolating a substance from impurities or other components. In the synthesis protocol, purification steps using column chromatography are crucial for obtaining pure compounds. This is essential in pharmaceuticals to ensure efficacy and safety of the final products.
11) Discussion:
The discussion section in academic articles serves to interpret results and contextualize findings within existing literature. In this research, the discussion highlights the efficiency of the synthesis method for imidazoles and compares it with existing methods, facilitating deeper understanding and advancement in the field of organic synthesis.
12) Venkata (Vemkata):
Venkata Reddy H. is a contributor to the research paper and affiliated with Bharathiar University. The mention of his name emphasizes collaboration in academic research, highlighting the roles individuals play in collective scientific inquiry leading to advancements in fields such as pharmaceutical chemistry.
13) Methane:
Methane is a simple hydrocarbon and a primary component of natural gas. While not directly addressed in the synthesis of imidazoles, its mention in varying solvent conditions (such as dichloromethane) emphasizes the significance of choosing appropriate solvents in chemical reactions, affecting yields and purity.
14) Purity:
Purity indicates the absence of impurities in a substance, crucial for the effectiveness of pharmaceutical compounds. The emphasis on product purity in the synthesis of imidazoles reflects quality standards necessary for developing safe and effective drugs. High purity is critical in ensuring consistent biological activity.
15) Medium:
In chemistry, the term medium refers to the solvent or environment in which reactions occur. The document specifies ethanol as the reaction medium for synthesizing imidazoles. The choice of medium influences reaction conditions, yields, and the overall efficacy of the synthesis process.
16) Water:
Water, as a solvent, plays a pivotal role in various chemical reactions and is often involved in purification processes post-synthesis. Its mention underscores the importance of considering environmental and health impacts during chemical processes, aligning with modern sustainable practices in organic synthesis.
17) Field:
The term 'field' refers to a specific domain of study or research. In this context, the field of pharmaceutical chemistry encompasses the synthesis and development of new compounds, highlighting the importance of interdisciplinary approaches that integrate biology, chemistry, and pharmacology to address healthcare challenges.
18) Kina:
Kina might refer to a typo; perhaps intended as 'Kinas,' which relates to kinases—enzymes that regulate various cellular processes. The mention of their inhibitors in the discussion of imidazole derivatives connects the research to broader therapeutic applications, especially in targeting diseases influenced by kinase activity.
19) Drug:
In pharmacology, a drug is a chemical substance used to diagnose, cure, treat, or prevent disease. The synthesized imidazole derivatives are potential candidates for new drugs, emphasizing the significance of ongoing research in identifying and developing compounds that have therapeutic effects on various medical conditions.
Other Science Concepts:
Discover the significance of concepts within the article: ‘Efficient synthesis of tetrasubstituted imidazoles using Bi(III)Br.’. Further sources in the context of Science might help you critically compare this page with similair documents: