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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2188190Generated: October 29, 2026

Hydrochloric Acid → ethyl 1-methyl-1H-pyrazole-4-carboxylate

https://huagongshe.com/reaction/2188190

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
ReactantWaterHCID 962—
ReactantTert-Butyl nitriteHCID 10906—
ReactantEthyl 5-amino-1-methyl-1H-pyrazole-4-carboxylateHCID 271299—
SolventDimethylformamideHCID 6228—
Productethyl 1-methyl-1H-pyrazole-4-carboxylateHCID 1111626591.4%

Reaction Conditions

Temperature30 °C

Reaction Steps

To a solution of 90% t-butyl nitrite (50 mL, 0.37 mol) in 200 mL DMF was added in portions ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate (39 g, 0.23 mol), maintaining the temperature at around 30° C. After the addition, the resulting mixture was warmed to 50° C. and stirred at that temperature for 0.5 h. The mixture was poured into 100 mL conc HCl and 40 mL water and extracted with CH2Cl2. The organic solution was washed with water, brine, dried and concentrated. Vacuum distillation of the residue gave 32.4 g of ethyl 1-methyl-1H-pyrazole-4-carboxylate as a clear liquid. b.p. 65-80° C. at 0.1 torr.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS06410558B1
Source datasetuspto-grants-2002_06
ORD IDord-a15eaf762e3a45138fbb8ff9adc4922e
Source noteuspto-grants-2002_06