Ethyl 3-ethoxy-3-iminopropionate hydrochloride → Ethyl 2-[5-(2-thienyl)benzimidazol-2-yl]acetate

HRID 2377834Notes

Reaction equation

HRID 2377834 reaction equation
[N+:1]([C:4]1[CH:9]=[C:8]([C:10]2[S:11][CH:12]=[CH:13][CH:14]=2)[CH:7]=[CH:6][C:5]=1[NH2:15])([O-])=O.Cl.C(O[C:20](=N)[CH2:21][C:22]([O:24][CH2:25][CH3:26])=[O:23])C>CCO.[Pd]>[S:11]1[CH:12]=[CH:13][CH:14]=[C:10]1[C:8]1[CH:7]=[CH:6][C:5]2[N:15]=[C:20]([CH2:21][C:22]([O:24][CH2:25][CH3:26])=[O:23])[NH:1][C:4]=2[CH:9]=1

Participants

5

Reactant 2

HCID 75345Ethyl 3-ethoxy-3-iminopropionate hydrochlorideHCID 226648312-Nitro-4-(thiophen-2-yl)aniline

Product 1

HCID 22664640Ethyl 2-[5-(2-thienyl)benzimidazol-2-yl]acetate

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

2-Nitro-4-(2-thienyl)phenylamine (1.0 equivalent) and 10% Pd/C (0.1 equivalents) were suspended in anhydrous EtOH at room temperature. The reaction flask was evacuated and subsequently filled with H2. The resulting mixture was allowed to stir under a hydrogen atmosphere for 3 hours. Ethyl 3-ethoxy-3-iminopropanoate hydrochloride (2.0 equivalents) was then added and the resulting mixture was heated at reflux for 12 hours. After this time, the solution was filtered through a plug of Celite, concentrated, dissolved in 50 mL of 2 N HCl and washed with CH2Cl2. The aqueous layer was brought to pH 12 with concentrated NH4OH(aq) and extracted with CH2Cl2. The combined organic layers were dried with MgSO4 and concentrated to yield a brown oil which was purified by silica gel chromatography (5:95 MeOH:CH2Cl2) to provide a yellow solid. LC/MS m/z 287.1 (MH+), Rt 1.98 minutes.

Workup

  1. customThe reaction flask was evacuated
  2. additionsubsequently filled with H2
  3. temperaturethe resulting mixture was heated
  4. temperatureat reflux for 12 hours
  5. filtrationAfter this time, the solution was filtered through a plug of Celite
  6. concentrationconcentrated
  7. dissolutiondissolved in 50 mL of 2 N HCl
  8. washwashed with CH2Cl2
  9. extractionextracted with CH2Cl2
  10. dry with materialThe combined organic layers were dried with MgSO4
  11. concentrationconcentrated
  12. customto yield a brown oil which
  13. customwas purified by silica gel chromatography (5:95 MeOH:CH2Cl2)
  14. customto provide a yellow solid

Sources & evidence

ORD record
ord-b5adfc26c63e414792cc1450518937d6
Source dataset
uspto-grants-2008_12
Patent number
US07470709B2

Reaction notes

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