4-Chloro-1H-pyrrolo[2,3-b]pyridine TCI C2470

TCI C2470 4-Chloro-1H-pyrrolo[2,3-b]pyridine is a heterocyclic building block widely known as a 7-azaindole derivative, meaning an indole framework in which one of the carbon atoms of the benzene ring has been replaced by nitrogen. In this particular compound, a chlorine atom occupies the four position and serves as the principal site of reaction. The azaindole scaffold is highly valued in medicinal chemistry because it combines a pyrrole nitrogen that acts as a hydrogen bond donor with a pyridine nitrogen that acts as an acceptor, allowing it to mimic binding patterns frequently encountered in the nucleotide binding regions of target proteins.

The reason this material is so frequently selected lies in the directed reactivity of the four position. The chlorine atom sits on an electron poor pyridine ring, so it can be displaced through nucleophilic aromatic substitution or exploited in palladium catalysed cross coupling reactions such as Suzuki, Stille and Sonogashira couplings, as well as Buchwald-Hartwig amination. The pyrrole nitrogen can first be masked with a common protecting group so that the reaction proceeds cleanly, then deprotected at the final stage. The three position of the pyrrole ring remains available for halogenation or acylation, so the scaffold permits functionalisation at several distinct points.

In Indonesian laboratories this building block is typically encountered in synthetic organic and medicinal chemistry groups at universities and research institutes, as well as in contract research settings preparing kinase-directed compound libraries. It is normally used at small scale on the bench, weighed out for multi-step sequences in which the chlorinated position is elaborated first and the pyrrole nitrogen is unmasked afterwards. Groups working on heterocyclic methodology also use it as a reference substrate when developing coupling conditions.

• Palladium catalysed cross coupling research, because the chlorine at the four position participates directly in Suzuki, Stille and Sonogashira reactions to install aryl, vinyl or alkynyl groups.
• Buchwald-Hartwig amination studies, where the same four position chlorine is converted into a carbon-nitrogen bond, giving access to aminated azaindoles under palladium catalysis.
• Nucleophilic aromatic substitution work, since the electron poor pyridine ring activates the chlorine toward displacement by a range of nucleophiles without requiring a metal catalyst.
• Medicinal chemistry scaffold construction, because the pyrrole nitrogen donor and pyridine nitrogen acceptor together mimic binding patterns found in nucleotide binding regions of target proteins.
• Multi-point functionalisation sequences, as the three position of the pyrrole ring stays open for halogenation or acylation after the four position has already been elaborated.

• Chemical name: 4-Chloro-1H-pyrrolo[2,3-b]pyridine

Store the container tightly closed in a cool, dry and well ventilated place, away from direct sunlight, heat sources and incompatible materials, and follow any specific storage temperature stated on the manufacturer label. Keep the material in its original supplier container or in a clean, chemically compatible and clearly labelled alternative, and close it promptly after each weighing to limit exposure to moisture and air. Handle in a fume hood using a laboratory coat, chemical resistant gloves and safety glasses. Avoid generating dust, avoid contact with skin and eyes, and wash hands thoroughly after handling. Consult the safety data sheet before first use and dispose of residues and contaminated materials through the approved chemical waste route.

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