5-Chloro-3-iodoquinoline 1416801-73-4 98% off-white to light yellow crystalline powder pharmaceutical intermediate

1. Product Overview

5-Chloro-3-iodoquinoline (CAS 1416801-73-4) is a dihalogenated quinoline derivative bearing a chlorine atom at the 5-position and an iodine atom at the 3-position of the quinoline nucleus. Also referred to as Quinoline, 5-chloro-3-iodo-, it serves as a highly versatile electrophilic building block in medicinal chemistry and heterocyclic synthesis. The compound typically appears as an off-white to light yellow crystalline powder or solid at room temperature, widely used for constructing quinoline-based active pharmaceutical ingredients (APIs), kinase inhibitors, antimalarial agents, and anti-infectives. Its key value lies in regioselective reactivity: the C3–iodo is exceptionally active in Pd-catalyzed cross-couplings (Suzuki, Sonogashira, Buchwald–Hartwig, Negishi), while the C5–chloro is more stable but available for secondary SNAr or retained as a metabolically stabilizing halo substituent in final drug scaffolds.

2. Key Features and Advantages

• Orthogonal halogen reactivity: C3–I undergoes facile cross-coupling under mild Pd catalysis; C5–Cl remains intact for sequential late-stage diversification or retention as a bioisostere.

• Quinoline core is a privileged pharmacophore in drug discovery (antimalarials like chloroquine analogs, kinase inhibitors, antibacterials, CNS agents), enabling rapid SAR via C3 arylation/alkynylation/amination.

• High purity grade (≥98%) ensures clean conversion in multi-step pharmaceutical workflows with minimal dihalogen impurity crossover.

• Stable solid form at RT under dry conditions, facilitating accurate weighing, handling, and QC by HPLC, NMR (characteristic aromatic/iodo signals), and LC-MS.

• Compatible with standard protecting-group strategies (quinoline N-oxidation/reduction) and orthogonal iodo vs. chloro reactivity in high-throughput library synthesis.

3. Main Applications

• Pharmaceutical intermediate for quinoline-based drug candidates, especially antimalarial, kinase inhibitor, antiviral, and antibacterial R&D where 3,5-disubstituted quinolines are key pharmacophores.

• Building block for 3-arylated/alkynylated-5-chloroquinolines via Suzuki, Sonogashira, and Stille couplings at C3–I, followed by optional displacement of C5–Cl via SNAr.

• Intermediate in CRO/CDMO custom synthesis and academic research for quinoline library generation, C–H activation studies, and Miyaura borylation to 3-boronic esters then Suzuki sequences.

• Precursor to 5-chloroquinolin-3-ylboronic acids/esters (via Pd-catalyzed borylation) and further to diversified 3,5-disubstituted quinolines relevant to agrochemical and material programs.

• Used in fragment-based drug design to introduce a 5-chloro-3-iodoquinoline handle for Pd-catalyzed linkage to aromatic/aliphatic fragments via cross-coupling at C3.

4. Technical Specifications

5. Storage and Handling

Store in a cool, dry place at 2–8 °C in a tightly sealed, light-protected container under desiccated conditions; sealed dry at room temperature is also acceptable for short-to-medium term. For long-term storage, keep at –20 °C under an inert atmosphere (nitrogen or argon) to minimize moisture uptake and slow halogen hydrolysis or iodide sensitivity to light/air. The aryl iodide is stable under neutral conditions but should be protected from strong nucleophiles, bases, and prolonged UV exposure which may promote dehalogenation or hydrolysis. Handle in a well-ventilated area with standard PPE (lab coat, nitrile gloves, safety glasses). Reseal promptly after use. Under recommended dry, refrigerated conditions, shelf life is typically 24 months.

6. Safety Overview

Intended for research and synthetic use only; not for direct human or veterinary therapeutic administration. May cause irritation to eyes, skin, and respiratory tract upon contact or dust inhalation (typical GHS07 profile: H302/H315/H319/H335). Halogenated iodinated quinolines can be mildly irritating to mucous membranes and contain iodine which may pose additional sensitization risk; handle as a fine organic powder with standard laboratory precautions. Prevent dust generation. In case of skin contact, wash thoroughly with soap and water; for eye contact, rinse cautiously with plenty of water for several minutes and seek medical advice if irritation persists. Avoid contact with strong bases, nucleophiles, or metals unless intentionally performing a reaction. Dispose according to local regulations for halogenated heterocyclic organic laboratory chemicals (iodinated compounds require special halogen-waste handling). Always consult the latest SDS from the supplier before use.