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

HRID 1393741Notes

Reaction equation

HRID 1393741 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-d1b28eb68f994a47811234cdf0c59546
Source dataset
uspto-grants-2008_03
Patent number
US07345178B2

Reaction notes

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