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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2043575Generated: November 2, 2026

p-Toluenesulfonic acid → 6-Bromo-2-methylpyrazolo[1,5-a]pyrimidine

https://huagongshe.com/reaction/2043575

Reaction equation

Participants

RoleNameHCIDCharge
Reactantp-Toluenesulfonic acidHCID 6101—
Reactant2-BromopropanedialHCID 74945—
ReactantHCID 178418690HCID 178418690—
SolventEthanolHCID 702—
Product6-Bromo-2-methylpyrazolo[1,5-a]pyrimidineHCID 1598004130%

Reaction Conditions

Temperature80 °C

Reaction Steps

To a solution of 3-methyl-1H-pyrazol-5-amine a12 (64.8 mmol, 1 eq, 6.3 g) in EtOH (100 ml), in the presence of PTSA, is added bromomalonaldehyde x9 (64.8 mmol, 1 eq, 9.79 g). The mixture is heated at 80° C. for 12 hours. The solvent is evaporated under reduce pressure and the residue purified by chromatography on silicagel (hexane/AcOEt: 93/7 (v/v)). 6-bromo-2-methylpyrazolo[1,5-a]pyrimidine x14 is obtained as a white solid (4.04 g).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08586623B2
Source datasetuspto-grants-2013_11
ORD IDord-5cb45cd7af4947b8a97328c09c487cc9
Source noteuspto-grants-2013_11