Hydrochloric Acid → Ethyl 3-aminopyridazine-4-carboxylate

HRID 2217966Notes

Reaction equation

HRID 2217966 reaction equation
[NH2:1][C:2]1[N:3]=[N:4][CH:5]=[CH:6][C:7]=1[C:8]([OH:10])=[O:9].Cl.[C:12]1(C)C=CC(S(Cl)(=O)=O)=C[CH:13]=1>C(O)C>[CH2:12]([O:9][C:8]([C:7]1[CH:6]=[CH:5][N:4]=[N:3][C:2]=1[NH2:1])=[O:10])[CH3:13]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 73974-Toluenesulfonyl chlorideHCID 64052513-Amino-4-pyridazinecarboxylic acid

Product 1

HCID 68940790Ethyl 3-aminopyridazine-4-carboxylateYield 1,163.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

3-Aminopyridazine-4-carboxylic acid (1.68 g, prepared as in JOC, (1985), 50, 346) was refluxed in ethanol (170 ml) with concentrated hydrochloric acid (2 ml) and p-toluene-sulphonyl chloride (0.1 g) for 55 hours. The solvent was evaporated and ice water added to the residue, which was then neutralised with solid sodium bicarbonate. The mixture was extracted with chloroform, insoluble material filtered, the organic extract dried over magnesium sulphate and evaporated to give 3-aminopyridazine-4-carboxylic acid ethyl ester (1.02 g) as a white solid.

Workup

  1. customThe solvent was evaporated
  2. additionice water added to the residue, which
  3. extractionThe mixture was extracted with chloroform, insoluble material
  4. filtrationfiltered
  5. extractionthe organic extract
  6. dry with materialdried over magnesium sulphate
  7. customevaporated

Sources & evidence

ORD record
ord-5002fe2692d8471cab97158222e24642
Source dataset
uspto-grants-2008_08
Patent number
US07410967B2

Reaction notes

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