Ethyl bromopyruvate → 3-(2-Nitro-phenyl)-imidazo[2,1-b]thiazole-6-carboxylic acid ethyl ester

HRID 1667008

Reaction equation

HRID 1667008 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[C:10]1[N:11]=[C:12]([NH2:15])[S:13][CH:14]=1)([O-:3])=[O:2].Br[CH2:17][C:18](=O)[C:19]([O:21][CH2:22][CH3:23])=[O:20]>C(C(C)=O)C>[CH2:22]([O:21][C:19]([C:18]1[N:15]=[C:12]2[N:11]([CH:17]=1)[C:10]([C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=1[N+:1]([O-:3])=[O:2])=[CH:14][S:13]2)=[O:20])[CH3:23]

Participants

4

Reactant 2

HCID 66144Ethyl bromopyruvate2×HCID 5957794-(2-Nitrophenyl)thiazole-2-amine

Product 1

HCID 596802093-(2-Nitro-phenyl)-imidazo[2,1-b]thiazole-6-carboxylic acid ethyl esterYield 52.5%

Reagents, catalysts & solvents 1

HCID 6569Methyl Ethyl KetoneSolvent

Procedure

4-(2-Nitro-phenyl)-thiazol-2-ylamine (1.60 g, 7.2 mmol) was mixed with 50 mL of methyl ethyl ketone along 0.90 mL of ethyl bromopyruvate (7.2 mmol) and stirred under reflux for 24 hours. Another equivalent of ethyl bromopyruvate (0.90 mL, 7.2 mmol) was added and the reaction mixture was stirred under reflux for another 8 hours. The reaction mixture was cooled to room temperature and concentrated under reduced pressure. The resulting residue was purified by chromatography (Isco, gradient elution, CH2Cl2 to 95% CH2Cl2, 5% MeOH) to afford 1.2 g of 3-(2-nitro-phenyl)-imidazo[2,1-b]thiazole-6-carboxylic acid ethyl ester (52% yield).

Workup

  1. temperatureunder reflux for 24 hours
  2. stirringthe reaction mixture was stirred
  3. temperatureunder reflux for another 8 hours
  4. concentrationconcentrated under reduced pressure
  5. customThe resulting residue was purified by chromatography (Isco, gradient elution, CH2Cl2 to 95% CH2Cl2, 5% MeOH)

Sources & evidence

ORD record
ord-c896240064c74f03abb48a8a0d0aa40f
Source dataset
uspto-grants-2011_10
Patent number
US08044198B2

Linked notes

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