2-Butanone, 3-bromo- → HCID 57437185, compound

HRID 560293Notes

Reaction equation

HRID 560293 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8](=[S:12])[NH:9][C:10]=1[CH3:11])=[O:5])[CH3:2].Br[CH:14]([CH3:18])[C:15](=O)[CH3:16].O=P(Cl)(Cl)Cl>CCO>[CH2:1]([O:3][C:4]([C:6]1[N:7]2[C:8]([S:12][C:14]([CH3:18])=[C:15]2[CH3:16])=[N:9][C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

5

Reactant 3

HCID 131422-Butanone, 3-bromo-HCID 24813Phosphorus oxychlorideHCID 3824588MLS002639316

Product 1

HCID 57437185HCID 57437185, compound

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 5-methyl-2-thioxo-2,3-dihydro-1H-imidazole-4-carboxylic acid ethyl ester (10.7 mmol) and 3-bromo-2-butanone (10.7 mmol) in EtOH (16 mL) is heated at reflux for 3 h. The solvents are removed in vacuo and POCl3 (161 mmol) is added. The mixture is stirred at reflux for 3 h, concentrated in vacuo and diluted with chloroform. Ice water is added and the mixture is neutralized by addition of Na2CO3. The layers are separated and the aq. layer is extracted with chloroform. The combined organic layers are dried over Na2SO4 and concentrated in vacuo to give a mixture of two regioisomers which are separated by FC (heptane/EtOAc 9/1 to EtOAc). 2,3,6-trimethyl-imidazo[2,1-b]thiazole-5-carboxylic acid ethyl ester is obtained as minor isomer. LC-MS: tR=0.84 min; [M+H]+=239.0.

Workup

  1. temperatureis heated
  2. temperatureat reflux for 3 h
  3. additionis added
  4. temperatureat reflux for 3 h
  5. concentrationconcentrated in vacuo
  6. additiondiluted with chloroform
  7. additionIce water is added
  8. additionthe mixture is neutralized by addition of Na2CO3
  9. customThe layers are separated
  10. extractionthe aq. layer is extracted with chloroform
  11. dry with materialThe combined organic layers are dried over Na2SO4
  12. concentrationconcentrated in vacuo
  13. customto give
  14. additiona mixture of two regioisomers which
  15. customare separated by FC (heptane/EtOAc 9/1 to EtOAc)

Sources & evidence

ORD record
ord-54c7899328bb4cb59dac35082035426e
Source dataset
uspto-grants-2011_11
Patent number
US08063099B2

Reaction notes

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