Thiourea → Ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate

HRID 2412722Notes

Reaction equation

HRID 2412722 reaction equation
[OH:1][N:2]=[C:3]([C:9]([CH2:11]Br)=O)[C:4]([O:6][CH2:7][CH3:8])=[O:5].[NH2:13][C:14]([NH2:16])=[S:15]>C(O)C>[OH:1][N:2]=[C:3]([C:9]1[N:13]=[C:14]([NH2:16])[S:15][CH:11]=1)[C:4]([O:6][CH2:7][CH3:8])=[O:5]

Participants

4

Reactant 2

HCID 2723790ThioureaHCID 178472904HCID 178472904, compound

Product 1

HCID 6738988Ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
60 °C

Procedure

A mixture of ethyl 2-hydroxyimino-4-bromoacetoacetate (a mixture of syn and anti isomers) (2.4 g) and thiourea (0.76 g) in ethanol (15 ml) was stirred for 1 hour at 60° C. Ethanol was distilled off under reduced pressure and water was added to the residue. The resultant mixture was adjusted to pH 1.0 and washed with ethyl acetate. The aqueous layer was adjusted to pH 4.5 with triethylamine and extracted with ethyl acetate. The extract was washed with water and a saturated sodium chloride aqueous solution and dried over magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was subjected to column chromatography on silica gel using a mixture of ethyl acetate and benzene (1:3) as developing solvent. The eluates containing syn isomer were collected and concentrated to give ethyl 2-hydroxyimino-2-(2-amino-1,3-thiazol-4-yl)acetate (syn isomer) (0.3 g).

Workup

  1. distillationEthanol was distilled off under reduced pressure and water
  2. additionwas added to the residue
  3. washwashed with ethyl acetate
  4. extractionextracted with ethyl acetate
  5. washThe extract was washed with water
  6. dry with materiala saturated sodium chloride aqueous solution and dried over magnesium sulfate
  7. distillationThe solvent was distilled off under reduced pressure
  8. additiona mixture of ethyl acetate and benzene (1:3)
  9. additionThe eluates containing syn isomer
  10. customwere collected
  11. concentrationconcentrated

Sources & evidence

ORD record
ord-f598e7396c184a49bcfc7106c82b414a
Source dataset
uspto-grants-1985_01
Patent number
US04493833

Reaction notes

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