N-bromobutanimide → Ethyl 5-bromo-2-methylthiazole-4-carboxylate

HRID 383944

Reaction equation

HRID 383944 reaction equation
[CH3:1][C:2]1[S:3][CH:4]=[C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:6]=1.C1C(=O)N([Br:19])C(=O)C1.C([O-])(O)=O.[Na+]>CC#N>[Br:19][C:4]1[S:3][C:2]([CH3:1])=[N:6][C:5]=1[C:7]([O:9][CH2:10][CH3:11])=[O:8]

Participants

5

Reactant 3

HCID 67184N-bromobutanimide2×HCID 293353Ethyl 2-methyl-1,3-thiazole-4-carboxylateHCID 516892Sodium Bicarbonate

Product 1

HCID 59291239Ethyl 5-bromo-2-methylthiazole-4-carboxylateYield 40.1%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of ethyl 2-methyl-1,3-thiazole-4-carboxylate (14.53 g) in MeCN (150 mL) was added NBS (22.66 g), followed by heating under reflux for 3 hours. To the reaction mixture was added NBS (7.55 g), followed by heating under reflux for 2 hours. Under ice-cooling, to the reaction mixture was added a saturated aqueous NaHCO3 solution, followed by stirring for 5 minutes, and then extraction with EtOAc. The organic layer was dried over MgSO4 and then concentrated under reduced pressure. The residue obtained was purified by silica gel column chromatography (hexane:EtOAc=from 100:0 to 60:40) to obtain ethyl 5-bromo-2-methyl-1,3-thiazole-4-carboxylate (8.52 g) as a yellow solid.

Workup

  1. temperatureby heating
  2. temperatureunder reflux for 3 hours
  3. temperatureby heating
  4. temperatureunder reflux for 2 hours
  5. temperatureUnder ice-cooling, to the reaction mixture
  6. extractionextraction with EtOAc
  7. dry with materialThe organic layer was dried over MgSO4
  8. concentrationconcentrated under reduced pressure
  9. customThe residue obtained
  10. customwas purified by silica gel column chromatography (hexane:EtOAc=from 100:0 to 60:40)

Sources & evidence

ORD record
ord-a8c009059a5f495dae254bba06320339
Source dataset
uspto-grants-2013_02
Patent number
US08367696B2

Linked notes

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