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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 243336Generated: October 30, 2026

Hydrochloric Acid → 5-Chloro-1H-pyrazolo(4,3-d)pyrimidine

https://huagongshe.com/reaction/243336

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
ReactantHCID 59797350HCID 59797350—
SolventTetrahydrofuranHCID 8028—
Product5-Chloro-1H-pyrazolo(4,3-d)pyrimidineHCID 5979694747.8%

Reaction Steps

Hydrochloric acid (70 mL, 8%) was added dropwise to a solution of 1-[5-chloro-1H-pyrazolo[4,3-d]pyrimidin-1-yl]ethan-1-one (7 g, 33.83 mmol, 1.00 equiv, 95%) in tetrahydrofuran (70 mL) at 50° C. The resulting solution was refluxed for 30 min and then extracted with 2×100 mL of ethyl acetate. The organic layers were combined, dried over anhydrous sodium sulfate and concentrated under vacuum to give 2.5 g (45%) of 5-chloro-1H-pyrazolo[4,3-d]pyrimidine as a white solid.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08653089B2
Source datasetuspto-grants-2014_02
ORD IDord-64f3d0304fd8400d87ba03b2ba0b13f8
Source noteuspto-grants-2014_02