7-Chloro-1H-pyrazolo[4,3-d]pyriMidine

7-Chloro-1H-pyrazolo[4,3-d]pyrimidine is a versatile core scaffold in the discovery of protein kinase inhibitors, where it serves as a hinge‑binding motif analogous to pyrrolo[2,3‑d]pyrimidine but with a distinct hydrogen‑bond pattern. The chlorine of 7-Chloro-1H-pyrazolo[4,3-d]pyrimidine is readily displaced with amines, alkoxides, or boronic acids to generate 7‑substituted‑1H‑pyrazolo[4,3‑d]pyrimidines in a single step. Numerous patent applications feature 7-Chloro-1H-pyrazolo[4,3-d]pyrimidine as a key intermediate in the preparation of JAK, CDK, and PI3K inhibitors, as well as antiviral agents. Because 7-Chloro-1H-pyrazolo[4,3-d]pyrimidine is a crystalline solid, it can be accurately weighed and handled without special precautions, facilitating both high‑throughput parallel synthesis and pilot‑scale campaigns.

Product Parameters

Quality Assurance at Cosperpharm

Each batch undergoes:

● Gas chromatography (GC) – purity ≥97.0%

● Non‑aqueous titration – purity ≥97.0%

● Refractive index – confirmatory analysis

● ¹H NMR – structural verification

● Appearance – colorless to light yellow to light orange clear liquid

A comprehensive COA, MSDS (with full GHS information), and certificate of origin accompany every shipment.

Storage Conditions

Store 7-Chloro-1H-pyrazolo[4,3-d]pyrimidine at room temperature (15–25 °C) or 2–8 °C in a tightly closed container, protected from light and moisture. The compound is stable under these conditions for at least 36 months.

Application Scenarios

1.JAK Inhibitor Core

Used as the central heterocycle in selective JAK2 and JAK3 inhibitors for autoimmune diseases.

2.CDK Inhibitor Programs

Serves as the hinge‑binding motif for cyclin‑dependent kinase inhibitors in oncology.

3.Antiviral Agent Discovery

Incorporated into nucleoside analogs targeting viral polymerases of HCV and RSV.

4.High‑Throughput Library Production

The chlorine is displaced in parallel with diverse amines to create a focused kinase inhibitor library.

5.Chemical Biology Probes

Functionalized with linkers for affinity chromatography or PROTAC development.

Contact Us

If this pyrazolo‑pyrimidine scaffold aligns with your current kinase or antiviral program, reach out to Cosperpharm’s heterocycle product manager — we can arrange a virtual meeting to discuss your specifications and provide a comprehensive technical proposal.