Sulfuric Acid → 4-Amino-1-methyl-5-methylaminopyrazole

HRID 1376889Notes

Reaction equation

HRID 1376889 reaction equation
Br[C:2]1[C:6]([N+:7]([O-])=O)=[C:5]([NH:10][CH3:11])[N:4]([CH3:12])[N:3]=1.S(=O)(=O)(O)O>O>[NH2:7][C:6]1[CH:2]=[N:3][N:4]([CH3:12])[C:5]=1[NH:10][CH3:11]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 229186403-Bromo-1-methyl-5-methylamino-4-nitropyrazole

Product 1

HCID 186927564-Amino-1-methyl-5-methylaminopyrazoleYield 137.7%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

0.5 g (2.13 mmoles) of 3-bromo-1-methyl-5-methylamino-4-nitropyrazole are hydrogenated in a solution of 220 mg (2.13 mmoles) sulfuric acid in 20 ml water for 14 hours after adding the catalyst as described in method (2). After filtering the catalyst, the filtrate is reduced until dry and the residue is recrystallized from ethanol. 370 mg (78 percent of theory) of 4-amino-1-methyl-5-methylaminopyrazole hydrosulfate are obtained in the form of colorless crystals with a melting point of 185° to 188° C.

Workup

  1. additionafter adding the catalyst
  2. filtrationAfter filtering the catalyst
  3. customuntil dry
  4. customthe residue is recrystallized from ethanol

Sources & evidence

ORD record
ord-4887a720c9b04feb9bb6099fe2063b4b
Source dataset
uspto-grants-1997_09
Patent number
US05663366

Reaction notes

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