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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 908891Generated: November 1, 2026

Hydrochloric Acid → tert-butyl 3-amino-1H-thieno[2,3-c]pyrazole-5-carboxylate

https://huagongshe.com/reaction/908891

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
ReactantTert-butyl 4-cyano-5-hydrazinothiophene-2-carboxylateHCID 11622817—
SolventMethanolHCID 887—
SolventEthyl AcetateHCID 8857—
Producttert-butyl 3-amino-1H-thieno[2,3-c]pyrazole-5-carboxylateHCID 17845063689.5%

Reaction Steps

A mixture of tert-butyl 4-cyano-5-hydrazinothiophene-2-carboxylate (1.0 g, 4.2 mmol) and hydrochloric acid (0.7 mL of 37% solution) in methyl alcohol (15 mL) was stirred at room temperature for 14 hours. The reaction mixture was diluted with ethyl acetate (50 mL) and washed with an aqueous solution of sodium bicarbonate. Organic layer was separated, dried over anhydrous sodium sulfate, and evaporated to give 0.9 g of the title compound.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08017643B2
Source datasetuspto-grants-2011_09
ORD IDord-fad4e1ba06d540e5b42d7e4cceb87736
Source noteuspto-grants-2011_09