4-Pyridinecarbothioamide → 2-(4-Pyridyl)-thiazole-5-acetic acid ethyl ester

HRID 848580Notes

Reaction equation

HRID 848580 reaction equation
[N:1]1[CH:6]=[CH:5][C:4]([C:7](=[S:9])[NH2:8])=[CH:3][CH:2]=1.[CH2:10]([O:12][C:13](=[O:19])[CH2:14][CH:15](Br)[CH:16]=O)[CH3:11]>C(O)C>[CH2:10]([O:12][C:13](=[O:19])[CH2:14][C:15]1[S:9][C:7]([C:4]2[CH:5]=[CH:6][N:1]=[CH:2][CH:3]=2)=[N:8][CH:16]=1)[CH3:11]

Participants

4

Reactant 2

HCID 27237884-PyridinecarbothioamideHCID 15576269Ethyl 3-bromo-4-oxobutanoate

Product 1

HCID 543385082-(4-Pyridyl)-thiazole-5-acetic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Pyridine-4-thioamide (1.38 g, 0.01 mole) and 3-bromo-4-oxobutyric acid ethyl ester (3.1 g., 0.015 mole) in ethanol (50 ml) are heated at reflux for six hours. After cooling the solvent is evaporated and the residue is neutralized with sodium bicarbonate solution and then extracted with chloroform (300 ml.). The chloroform solution is washed with water, dried with (MgSO4) and evaporated to yield crude 2-(4-pyridyl)-thiazole-5-acetic acid ethyl ester. Purification is carried out by dissolving in acetone and adding petroleum ether to induce crystallization. When this ester intermediate is treated with methanol solution saturated with ammonia gas (25 ml./g. of ester) for 3 days at room temperature 2-(4-pyridyl)thiazol-5-ylacetamide is obtained after partial evaporation of the methanol. Purification is carried out by recrystallization from ethanol. When the amide is treated according to the procedure in Example 1, there is obtained 3-hydroxy-4-[2-(4-pyridyl)thiazol-5-yl]-3-pyrroline-2,5-dione.

Workup

  1. temperatureat reflux for six hours
  2. temperatureAfter cooling the solvent
  3. customis evaporated
  4. extractionextracted with chloroform (300 ml.)
  5. washThe chloroform solution is washed with water
  6. dry with materialdried with (MgSO4)
  7. customevaporated

Sources & evidence

ORD record
ord-29141791bd484e6299003ae9033d5ef2
Source dataset
uspto-grants-1981_10
Patent number
US04296237

Reaction notes

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