6-Amino-5-Bromoquinoxaline: A Versatile Building Block for Medicinal Chemistry
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6-Amino-5-Bromoquinoxaline: A Versatile Building Block for Medicinal Chemistry
Quinoxaline derivatives have been well-established as a promising class of compounds with diverse pharmacological activities, including anticancer, antimicrobial, antiviral, anti-inflammatory, and antiparasitic effects. Among them, 6-aminoquinoxalines are of particular interest due to their ability to form hydrogen bonds and participate in π-π interactions with various biological targets, such as kinases, receptors, and enzymes. The introduction of a bromine atom at the 5-position of 6-aminoquinoxaline can further enhance its potency and selectivity, as well as improve its solubility and bioavailability. In this article, we will discuss the synthesis, properties, and applications of 6-amino-5-bromoquinoxaline (CAS: 50358-63-9), a valuable building block for medicinal chemistry.
Synthesis
6-Amino-5-bromoquinoxaline can be prepared by several methods, such as the reaction of 6-nitro-5-bromoquinoxaline with tin and hydrochloric acid, followed by reduction with iron powder and hydrochloric acid. Alternatively, the bromination of 6-aminoquinoxaline with N-bromosuccinimide (NBS) or bromine in acetic acid can yield 6-amino-5-bromoquinoxaline in moderate to good yields. The purity and quality of the product can be further improved by recrystallization from solvents such as ethanol, methanol, or acetone.
Properties
6-Amino-5-bromoquinoxaline is a yellow to orange crystalline powder with a melting point of 232-235°C. It is sparingly soluble in water but soluble in most organic solvents such as dimethyl sulfoxide (DMSO), acetonitrile, and dichloromethane. The compound has a molecular weight of 232.03 g/mol and a molecular formula of C8H6BrN3.
Applications
6-Amino-5-bromoquinoxaline has been used as a versatile building block for the synthesis of various biologically active compounds. For example, it can serve as a precursor for the preparation of kinase inhibitors, such as 6-amino-4-(4-phenoxyphenylamino)-5-bromoquinoxaline, which has potent activity against epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor (PDGFR). Similarly, 6-amino-5-bromoquinoxaline can be converted into 6-amino-4-(3-chloro-4-fluorophenylamino)-5-bromoquinoxaline, which exhibits high selectivity for c-Met kinase and inhibits tumor growth in vivo.
In addition, 6-amino-5-bromoquinoxaline can be used as a starting material for the synthesis of antimalarial drugs, such as 6-(4-fluorophenyl)-5-bromo-2-methyl-1,2,4-triazolo[1,5-a]quinoxaline, which has potent activity against chloroquine-resistant strains of Plasmodium falciparum. Moreover, 6-amino-5-bromoquinoxaline can be employed for the preparation of fluorescent dyes and imaging agents, such as 6-amino-5-bromoquinoxaline-2,3-dione, which exhibits bright green fluorescence and can be used for labeling proteins and nucleic acids.
Conclusion
In summary, 6-amino-5-bromoquinoxaline is a valuable building block for medicinal chemistry, offering a wide range of possibilities for the synthesis of biologically active compounds. Its unique structural features, such as the presence of an amino and a bromine group, make it a versatile and potent tool for drug discovery and development. Ningbo Inno Pharmchem Co., Ltd. is a reliable manufacturer and supplier of 6-amino-5-bromoquinoxaline, ensuring high quality and competitive prices for customers worldwide.
