Chemical Identity and Structural Features

6-Bromo-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one (Aladdin SKU: B728612) is a bicyclic heteroaromatic compound in which a pyridine ring is fused with a partially saturated 1,4-oxazin-2-one ring at the [2,3-b] bond junction. The molecule thus incorporates two nitrogen atoms and one ring oxygen within its bicyclic framework, alongside a lactam (cyclic amide) carbonyl group at the 2-position of the oxazinone ring.

The bromine substituent at the 6-position of the pyridine ring constitutes a strategically placed electrophilic handle. Aryl bromides of this type are well-established partners in transition-metal-catalysed cross-coupling chemistry, enabling C–C and C–heteroatom bond formations under mild conditions. The secondary amine (NH) at the 1-position provides an additional site for diversification via alkylation, acylation, or sulfonylation. Together, these features make the compound a multifunctional scaffold for library synthesis.

The fused pyridooxazinone core is bioisosterically related to quinoxalinone and benzoxazinone systems that appear in bioactive natural products and pharmaceutical candidates, suggesting potential relevance to target engagement in drug discovery programmes.

Physicochemical Properties and Handling

As a bicyclic lactam containing both an aryl bromide and a ring NH, 6-Bromo-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one is expected to be a solid at room temperature with moderate polarity, reflecting the balance between the aromatic/hydrophobic pyridine ring and the polar amide and ether functionalities. Exact melting point, solubility data, and molecular weight should be confirmed from the certificate of analysis (CoA) supplied with each batch.

For routine laboratory handling, the compound should be stored in a cool, dry environment away from light, moisture, and strong oxidising agents. The NH group can participate in hydrogen bonding and may influence solubility in common organic solvents such as DMSO, DMF, and acetonitrile. Stock solutions prepared in DMSO are typically stable when stored at –20 °C under inert atmosphere; repeated freeze–thaw cycles should be minimised.

Standard laboratory personal protective equipment (gloves, safety glasses, and lab coat) should be worn when handling this reagent. Consult the Safety Data Sheet (SDS) prior to use for specific hazard classifications and first-aid measures relevant to the supplied batch.

Synthetic Applications and Cross-Coupling Chemistry

The aryl C–Br bond at the 6-position is the primary synthetic handle on this scaffold. It participates readily in a broad range of palladium- and nickel-catalysed transformations that are standard practice in modern medicinal chemistry:

• Suzuki–Miyaura coupling: Reaction with aryl- or heteroarylboronic acids under Pd catalysis installs biaryl or heteroaryl substituents at C-6, enabling rapid exploration of π-stacking interactions with biological targets.
• Buchwald–Hartwig amination: Coupling with primary or secondary amines under Pd/ligand catalysis converts the aryl bromide to an aryl amine, expanding access to amino-substituted pyridooxazinone analogues relevant to kinase inhibitor design.
• Negishi and Kumada coupling: Organozinc and Grignard reagents can be employed to introduce alkyl or aryl groups with complementary selectivity profiles.
• Miyaura borylation: Treatment with bis(pinacolato)diboron (B2pin2) under Pd catalysis converts the bromide to a pinacol boronate ester, which can serve as a coupling partner in its own right.

Beyond C–Br reactivity, the lactam NH offers opportunities for N-functionalisation. Base-mediated N-alkylation with alkyl halides, or N-acylation with acyl chlorides, diversifies the amide nitrogen and can modulate pharmacokinetic properties such as membrane permeability and metabolic stability in analogue series.

Relevance to Drug Discovery and Medicinal Chemistry

Bicyclic nitrogen-and-oxygen-containing heterocycles occupy a privileged position in drug discovery. The pyrido[2,3-b][1,4]oxazin-2-one core shares structural and electronic features with scaffolds found in approved pharmaceuticals targeting kinases, GPCRs, and ion channels, where the pyridine nitrogen can act as a hydrogen-bond acceptor and the lactam carbonyl can engage complementary donor residues in a binding site.

The bromine atom at C-6 not only facilitates synthetic elaboration but can itself participate in halogen bonding with protein residues (e.g., carbonyl oxygens, backbone amides), a non-covalent interaction increasingly exploited in fragment-based drug design and lead optimisation.

Researchers engaged in target-class campaigns—particularly those focused on kinase inhibitors, PDE inhibitors, or GPCR modulators—may find 6-Bromo-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one a useful entry point for structure–activity relationship (SAR) exploration. Its compact size and the presence of multiple diversification vectors make it suitable for fragment screening as well as as a core in larger lead compounds.

Ordering, Purity, and Quality Assurance

Aladdin Scientific supplies 6-Bromo-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one under SKU B728612. Each lot is accompanied by a Certificate of Analysis (CoA) documenting purity by HPLC or other orthogonal analytical techniques, structural confirmation by NMR and/or MS, and physical characterisation data including appearance and melting point where applicable.

Researchers requiring specific purity grades or custom pack sizes are encouraged to contact Aladdin Scientific's technical sales team. For large-scale procurement or custom synthesis inquiries, please reference SKU B728612 in all communications to ensure efficient order processing.

Proper storage conditions (typically sealed, cool, and dry) should be maintained upon receipt to preserve reagent integrity. The recommended shelf life and any special storage requirements will be stated on the CoA and product label supplied with each shipment.