Imidazole → 3-(5-Nitro-1h-benzoimidazol-2-ylsulfanyl)-2-oxo-propionic acid ethyl ester

HRID 895701Notes

Reaction equation

HRID 895701 reaction equation
[SH:1][C:2]1[NH:3][C:4]2[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[CH:8]=[CH:7][C:5]=2[N:6]=1.Br[CH2:15][C:16](=[O:22])[C:17]([O:19][CH2:20][CH3:21])=[O:18].N1C=CN=C1>CO.CC(C)=O>[CH2:20]([O:19][C:17](=[O:18])[C:16](=[O:22])[CH2:15][S:1][C:2]1[NH:6][C:5]2[CH:7]=[CH:8][C:9]([N+:11]([O-:13])=[O:12])=[CH:10][C:4]=2[N:3]=1)[CH3:21]

Participants

6

Reactant 3

HCID 795ImidazoleHCID 66144Ethyl bromopyruvateHCID 178526473HCID 178526473, compound

Product 1

HCID 1784731223-(5-Nitro-1h-benzoimidazol-2-ylsulfanyl)-2-oxo-propionic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 887MethanolSolvent

Conditions

Temperature
20 °C

Procedure

To a solution of 2-mercapto-5-nitrobenzimidazole (195 mg, 1.0 mmol) and ethyl 3-bromopyruvate (0.150 mL, 1.19 mmol) in methanol (2.5 mL) and acetone (2 mL) was added imidazole (68 mg, 1.0 mmol). The resulted solution was shaken at 20° C. for 4 hour. After the removal of solvents under vacuum, the residue was triturated with ethyl ether. The ether phase was discarded. The residue was treated with sodium bicarbonate aqueous solution and ethyl ether. The ether phase was washed successively with sodium bicarbonate aqueous solution, water, and dried over magnesium sulfate. Evaporation to dryness under vacuum gave 200 mg (65% of yield) of the expected product, 3-(5-nitro-1H-benzoimidazol-2-ylsulfanyl)-2-oxo-propionic acid ethyl ester. Proton NMR showed the product was sufficiently pure to be used without further purification. 1H-NMR (D3COD, 300 MHz) δ (ppm): 8.35 and 8.08 (2 br. s, 1H), 8.12 (d, J=8.7 Hz, 1H), 7.50 and 7.28 (2 br. s, 1H), 4.42 (q, J=7.1 Hz, 2H), 4.41 (br. s, 1H), 4.06 (br. s, 1H), 1.30 (t, J=7.1 Hz, 3H). MS (ESI) m/z: 310 (M+1, 100).

Workup

  1. customAfter the removal of solvents under vacuum
  2. customthe residue was triturated with ethyl ether
  3. additionThe residue was treated with sodium bicarbonate aqueous solution and ethyl ether
  4. washThe ether phase was washed successively with sodium bicarbonate aqueous solution, water
  5. dry with materialdried over magnesium sulfate
  6. customEvaporation to dryness under vacuum
  7. customgave

Sources & evidence

ORD record
ord-5fb55a96c7264c3a82fee9dfc0c2511c
Source dataset
uspto-grants-2005_07
Patent number
US06916850B2

Reaction notes

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