Sulfuric Acid → 5-Amino-1-(o-tolyl)-1H-pyrazole-4-carboxamide

HRID 237887Notes

Reaction equation

HRID 237887 reaction equation
S(=O)(=O)(O)O.[NH2:6][C:7]1[N:11]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=2[CH3:18])[N:10]=[CH:9][C:8]=1[C:19]#[N:20].[OH-:21].[Na+]>>[NH2:6][C:7]1[N:11]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=2[CH3:18])[N:10]=[CH:9][C:8]=1[C:19]([NH2:20])=[O:21]

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 12150557HCID 12150557, compound

Product 1

HCID 119839075-Amino-1-(o-tolyl)-1H-pyrazole-4-carboxamide

Conditions

Temperature
40 °C

Procedure

300 ml of 96% strength sulphuric acid are cautiously added to 40.0 g (201.8 mmol) of 5-amino-1-(2-methylphenyl)-1H-pyrazole-4-carbonitrile (Example 8A) while cooling in ice. The mixture is then heated to 40° C. and stirred for 2 hours at this temperature. After cooling, it is poured into 2 l of ice-water and cautiously neutralized with 50% strength sodium hydroxide solution. After extraction with ethyl acetate three times (2 l each time) the combined organic phases are washed with saturated sodium chloride solution and dried over sodium sulphate, and the solvent is distilled off under reduced pressure. 36.0 g (82% of theory) of product (purity>90%) are obtained and are employed without further purification in subsequent reactions.

Workup

  1. temperaturewhile cooling in ice
  2. temperatureAfter cooling
  3. extractionAfter extraction with ethyl acetate three times (2 l each time) the combined organic phases
  4. washare washed with saturated sodium chloride solution
  5. dry with materialdried over sodium sulphate
  6. distillationthe solvent is distilled off under reduced pressure
  7. custom36.0 g (82% of theory) of product (purity>90%) are obtained
  8. customare employed without further purification in subsequent reactions

Sources & evidence

ORD record
ord-c5a5f06693f2492d8ec54671766d47fd
Source dataset
uspto-grants-2014_02
Patent number
US08642605B2

Reaction notes

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