Hydrogen Peroxide → Ethyl 1,2,3,4-tetrahydropyrido[1,2-a]benzimidazole-7-carboxylate

HRID 1498895Notes

Reaction equation

HRID 1498895 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][C:12]=1[N:13]1[CH2:18][CH2:17][CH2:16][CH2:15][CH2:14]1)[C:5]([O:7][CH2:8][CH3:9])=[O:6].OO.C(=O)(O)[O-].[Na+]>C(O)=O>[CH2:18]1[N:13]2[C:12]3[CH:11]=[CH:10][C:4]([C:5]([O:7][CH2:8][CH3:9])=[O:6])=[CH:3][C:2]=3[N:1]=[C:14]2[CH2:15][CH2:16][CH2:17]1

Participants

5

Reactant 3

HCID 784Hydrogen PeroxideHCID 516892Sodium BicarbonateHCID 2818633Ethyl 3-amino-4-(1-piperidinyl)benzoate

Product 1

HCID 12493647Ethyl 1,2,3,4-tetrahydropyrido[1,2-a]benzimidazole-7-carboxylateYield 74.3%

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Procedure

Ethyl 3-amino-4-piperidin-1-ylbenzoate (5.38 g, 21.7 mmol) prepared in the Step 3-1-2 was dissolved in formic acid (90%, 40 ml). Hydrogen peroxide solution (20 ml) was added to the solution, and the mixture was heated under reflux for 40 minutes. After being allowed to cool, the mixture was neutralized with a saturated sodium bicarbonate solution and a 25% ammonia water and subjected to extraction with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and then concentrated. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1) to give the title compound (3.94 g, 74%) as a light-brown powder.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 40 minutes
  3. temperatureto cool
  4. extractiona 25% ammonia water and subjected to extraction with ethyl acetate
  5. dry with materialThe extract was dried over anhydrous magnesium sulfate
  6. concentrationconcentrated
  7. customThe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1)

Sources & evidence

ORD record
ord-3b7cd68e63b946f9821a33e07de30038
Source dataset
uspto-grants-2015_12
Patent number
US09200008B2

Reaction notes

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