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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 326988Generated: October 25, 2026

Piperazine → Thieno[2,3-b]pyridin-3-amine

https://huagongshe.com/reaction/326988

Reaction equation

Participants

RoleNameHCIDCharge
ReactantPiperazineHCID 4837—
ReactantN-methyl-2-pyrrolidoneHCID 13387—
ReactantMethyl 3-aminothieno(2,3-b)pyridine-2-carboxylateHCID 2820896—
SolventWaterHCID 962—
ProductThieno[2,3-b]pyridin-3-amineHCID 28992386%

Reaction Conditions

Temperature145 °C

Reaction Steps

A mixture of 3-aminothieno[2,3-b]pyridine-2-carboxylic acid methyl ester (8.00 g), piperazine (6.70 g), and N-methyl-2-pyrrolidinone (80 ml) was heated to 145° C. for 3 hr, under a nitrogen atmosphere. The solution was allowed to cool, diluted with water (400 ml), and extracted with ethyl acetate. The combined extracts were washed with water and brine dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated to give 4.94 g (86.0%) of residual thieno[2,3-b]pyridine-3-amine.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS05272148
Source datasetuspto-grants-1993_12
ORD IDord-5d479739d7d443faab94979cf3a2641f
Source noteuspto-grants-1993_12