Hydrochloric Acid → Pyrazole-1-carboxamidine monohydrochloride

HRID 2188268Notes

Reaction equation

HRID 2188268 reaction equation
[NH:1]1[CH:5]=[CH:4][CH:3]=[N:2]1.[N:6]#[C:7][NH2:8].[ClH:9]>C(COC)OC>[ClH:9].[N:1]1([C:7]([NH2:8])=[NH:6])[CH:5]=[CH:4][CH:3]=[N:2]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 1048PyrazoleHCID 9864Cyanamide

Product 1

HCID 2734672Pyrazole-1-carboxamidine monohydrochloride

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Procedure

In a 500 ml four-necked flask fitted with gas inlet tube and gas outlet tube, internal thermometer and reflux condenser with in each case two safety wash bottles connected upstream and downstream, 34.1 g (0.5 mol.) of pyrazole and 21.0 g (0.5 mol.) of cyanamide are dissolved in 330 ml of dimethoxyethane. At 80° C., dry hydrogen chloride gas is introduced into the reaction solution at a rate of about 15 l/h for about 50 minutes. The solution is then allowed to cool and the precipitated solid is removed by filtration. The product obtained is dried under reduced pressure (100 mbar, 80° C.) to give 1H-pyrazole-1-carboxamidine hydrochloride in the form of a colorless, finely crystalline solid. Yield: 70.6 g (96%), melting point: 160 to 168° C. (literature: 165 to 166° C.) 13C-NMR (DMSO-d6) δ 152.3, 146.0, 131.5, 111.9.

Workup

  1. customIn a 500 ml four-necked flask fitted with gas inlet tube and gas outlet tube
  2. temperatureinternal thermometer and reflux condenser with in each case two safety
  3. washwash bottles
  4. temperatureto cool
  5. customthe precipitated solid is removed by filtration
  6. customThe product obtained
  7. customis dried under reduced pressure (100 mbar, 80° C.)

Sources & evidence

ORD record
ord-264e7240b7f64caf8da43127b6a2ab64
Source dataset
uspto-grants-2002_06
Patent number
US06410745B1

Reaction notes

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