6-Bromo-7-Fluoroisoquinoline: Handling & Use Protocol

6-Bromo-7-fluoroisoquinoline is a halogenated bicyclic heteroaromatic building block widely employed in transition-metal-catalyzed cross-coupling reactions and as a versatile intermediate in the synthesis of pharmaceutically relevant compounds.

CAS Number

Not confirmed in source material — see review flags

Molecular Formula

C₉H₅BrFN

Molecular Weight

226.05 g/mol

Key Functional Handles

C–Br (position 6) for cross-coupling; C–F (position 7) for SNAr or directed metalation

Storage Condition

Store in a cool, dry place away from light; confirm exact conditions on CoA

Primary Applications

Suzuki–Miyaura, Buchwald–Hartwig, and Negishi coupling reactions; medicinal chemistry intermediate

Materials and Safety Precautions

Before beginning any procedure with 6-Bromo-7-fluoroisoquinoline (SKU B173061), consult the Safety Data Sheet (SDS) provided by Aladdin Scientific. As a halogenated aromatic heterocycle, this compound should be handled with appropriate personal protective equipment (PPE), including nitrile gloves, safety goggles, and a lab coat. All weighing and dissolution steps should be performed inside a well-ventilated fume hood.

Required materials:

• 6-Bromo-7-fluoroisoquinoline (B173061)
• Analytical balance (0.1 mg resolution recommended)
• Amber glass vials or screw-cap vials for stock solutions
• Anhydrous solvents as appropriate (e.g., DMF, DMSO, THF, or DCM)
• Inert gas line (nitrogen or argon) for moisture-sensitive applications
• Appropriate PPE (gloves, goggles, lab coat)

Note: Verify the exact hazard classification on the current SDS before use. Flag any discrepancies with Aladdin Scientific technical support.

Dissolution and Stock Solution Preparation

6-Bromo-7-fluoroisoquinoline is a solid at room temperature. It is soluble in common organic solvents including DMSO, DMF, THF, and dichloromethane. Aqueous solubility is limited; avoid water-only systems unless solubilizing agents are employed.

Step-by-step stock solution preparation:

1. Allow the sealed vial to equilibrate to room temperature (approximately 15–20 minutes) before opening to minimize condensation onto the solid.
2. Tare an appropriate vial on an analytical balance inside the fume hood.
3. Transfer the required mass of 6-Bromo-7-fluoroisoquinoline using a clean spatula. Record the exact mass.
4. Add anhydrous solvent (e.g., anhydrous DMSO for biological assays, or anhydrous THF for organometallic reactions) to achieve the desired concentration. A stock concentration of 0.1–0.5 M is typical for synthetic applications.
5. Cap the vial immediately and vortex or gently swirl until the solid is fully dissolved. Mild warming (≤40 °C water bath) may assist dissolution if necessary.
6. Label the vial with compound name, SKU (B173061), concentration, solvent, preparation date, and operator initials.
7. Store stock solutions in amber vials under inert atmosphere at –20 °C if not used immediately. Verify stability on the CoA.

Review flag: Specific solubility values (mg/mL) are not confirmed in the source material and should be verified experimentally or from the CoA.

Application in Cross-Coupling Reactions

The C–Br bond at position 6 of 6-Bromo-7-fluoroisoquinoline is the primary site for transition-metal-catalyzed cross-coupling reactions, while the C–F bond at position 7 offers orthogonal reactivity for nucleophilic aromatic substitution (SNAr) or directed ortho-metalation strategies. This dual-handle functionality makes the compound a versatile intermediate in medicinal chemistry and materials science.

General procedure for Suzuki–Miyaura coupling (illustrative):

1. Charge a flame-dried Schlenk flask or round-bottom flask with 6-Bromo-7-fluoroisoquinoline (1.0 equiv), the desired aryl- or heteroarylboronic acid or ester (1.1–1.5 equiv), and a palladium catalyst (e.g., Pd(PPh₃)₄ or Pd(dppf)Cl₂, 2–5 mol%).
2. Add an appropriate base (e.g., K₂CO₃ or Cs₂CO₃, 2–3 equiv) and a suitable solvent system (e.g., dioxane/water 4:1 or DMF/water).
3. Degas the mixture by three freeze-pump-thaw cycles or by sparging with inert gas for 15 minutes.
4. Stir the reaction under inert atmosphere at 80–100 °C for 12–18 hours, or until TLC/HPLC analysis confirms consumption of starting material.
5. Cool to room temperature, dilute with ethyl acetate, wash with water and brine, dry over Na₂SO₄, filter, and concentrate under reduced pressure.
6. Purify the product by silica gel column chromatography or preparative HPLC as appropriate.

Note: Reaction conditions are illustrative and should be optimized for each specific substrate pair. Exact catalyst loadings, temperatures, and times are subject to review; see review flags.

Quality Control and Analytical Verification

Upon receipt of 6-Bromo-7-fluoroisoquinoline (B173061), verify compound identity and purity using the Certificate of Analysis (CoA) supplied by Aladdin Scientific. The following analytical methods are recommended for routine quality confirmation:

• ¹H NMR spectroscopy: Confirm the aromatic proton pattern characteristic of a 6,7-disubstituted isoquinoline. Expect signals consistent with three aromatic protons and the isoquinoline C1–H and C3–H resonances.
• ¹⁹F NMR spectroscopy: A single fluorine resonance in the aromatic region (typically –110 to –120 ppm relative to CFCl₃) confirms the presence and environment of the ring fluorine.
• HPLC purity: Assess purity by reverse-phase HPLC (C18 column, UV detection at 254 nm). Aladdin Scientific's CoA will specify the minimum purity grade; typical research-grade material is ≥97% by HPLC.
• Mass spectrometry: Confirm molecular ion consistent with C₉H₅BrFN (MW 226.05); expect characteristic bromine isotope pattern (M and M+2, approximately 1:1 ratio).
• Melting point: Measure and compare against the CoA value as an additional identity check.

Review flag: Exact NMR chemical shift values and melting point are not available in the source material; reference values should be taken from the CoA or a validated spectral database.

Storage, Stability, and Disposal

Storage: Store 6-Bromo-7-fluoroisoquinoline in a tightly sealed container in a cool, dry, and well-ventilated location, protected from light and moisture. Refer to the CoA for specific temperature recommendations. Under recommended storage conditions, the compound is expected to be stable for an extended period; however, periodically re-verify purity by HPLC or NMR if long-term storage is required.

Stability considerations: Halogenated isoquinolines are generally stable under ambient conditions when properly sealed, but prolonged exposure to moisture, heat, or strong light may lead to gradual degradation. Protect stock solutions from repeated freeze-thaw cycles by aliquoting prior to storage.

Waste disposal: Dispose of all waste containing 6-Bromo-7-fluoroisoquinoline in accordance with local, institutional, and national regulations for halogenated organic waste. Do not dispose of via drain or general waste. Consult your institution's Environmental Health and Safety (EHS) office for guidance on proper disposal routes, including incineration at a licensed facility.

Review flag: Specific shelf-life data and degradation kinetics are not available in the source material; consult the CoA or contact Aladdin Scientific technical support for confirmed stability data.

Frequently asked questions

What solvents are recommended for dissolving 6-Bromo-7-fluoroisoquinoline?

6-Bromo-7-fluoroisoquinoline dissolves readily in polar aprotic solvents such as DMSO, DMF, and THF, as well as in chlorinated solvents like dichloromethane. Aqueous solubility is low, so water-only systems should be avoided unless a co-solvent or solubilizing agent is used. Always use anhydrous solvents for moisture-sensitive reactions.

Which positions of 6-Bromo-7-fluoroisoquinoline are most reactive in cross-coupling reactions?

The C–Br bond at position 6 is the primary site for palladium-catalyzed cross-coupling reactions such as Suzuki–Miyaura, Negishi, and Buchwald–Hartwig couplings, due to the greater oxidative addition reactivity of C–Br versus C–F bonds. The C–F bond at position 7 can be selectively engaged in nucleophilic aromatic substitution (SNAr) reactions under appropriate nucleophile and base conditions, providing orthogonal functionalization opportunities.

How should I store 6-Bromo-7-fluoroisoquinoline to maintain its purity?

Store the compound in a tightly sealed container, away from light and moisture, in a cool and dry location. For long-term storage, an inert atmosphere (nitrogen or argon) is advisable. If preparing stock solutions, aliquot them to avoid repeated freeze-thaw cycles and store at –20 °C. Always consult the Aladdin Scientific CoA for the specific recommended storage conditions for lot B173061.

Is 6-Bromo-7-fluoroisoquinoline suitable for use in medicinal chemistry programs?

Yes, 6-Bromo-7-fluoroisoquinoline is a recognized building block in medicinal chemistry due to the isoquinoline scaffold's prevalence in bioactive molecules and approved drugs. The halogen substituents allow for late-stage diversification through cross-coupling and SNAr chemistry, enabling the efficient construction of compound libraries. Researchers should confirm purity and identity via the CoA before use in biological assays.

References

1. Aladdin Scientific. Certificate of Analysis for 6-Bromo-7-fluoroisoquinoline, SKU B173061. Shanghai: Aladdin Scientific.
2. Joule, J. A.; Mills, K. Heterocyclic Chemistry, 5th ed. Wiley-Blackwell: Oxford, 2010. (General reference for isoquinoline chemistry)
3. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.