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

HRID 2183567Notes

Reaction equation

HRID 2183567 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

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-3fe32a13d8124c90a03ecee674e9063c
Source dataset
uspto-grants-2005_05
Patent number
US06900218B2

Reaction notes

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