Diethyl Ether → 2-(2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide

HRID 892525Notes

Reaction equation

HRID 892525 reaction equation
[CH3:1][C:2]1([CH3:18])[CH:7]=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][N:9]=2)[C:5]2[CH:14]=[CH:15][CH:16]=[CH:17][C:4]=2[O:3]1.ClC1C=CC=C(C(OO)=[O:27])C=1.C(OCC)C>ClCCl>[CH3:1][C:2]1([CH3:18])[CH:7]=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][N+:9]=2[O-:27])[C:5]2[CH:14]=[CH:15][CH:16]=[CH:17][C:4]=2[O:3]1

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 70297m-Chloroperbenzoic acidHCID 187551522,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran

Product 1

HCID 543388622-(2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxideYield 2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1.61 g of 2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran were dissolved in 10 ml of dichloromethane at room temperature and 2.0 g of m-chloroperbenzoic acid were added. After 1 hour the mixture was washed with sodium bisulphite solution, sodium bicarbonate solution and water. The organic phase was dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using ethyl acetate/ethanol/formic acid (40:4:1) for the elution. The product was obtained as an oil which solidified upon trituration with diethyl ether. Recrystallization from toluene gave 0.034 g of 2-(2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide of melting point 148°-150° C.

Workup

  1. washAfter 1 hour the mixture was washed with sodium bisulphite solution, sodium bicarbonate solution and water
  2. dry with materialThe organic phase was dried over sodium sulphate
  3. customevaporated
  4. customThe residue was chromatographed on silica gel
  5. washfor the elution
  6. customThe product was obtained as an oil which
  7. customRecrystallization from toluene

Sources & evidence

ORD record
ord-235420d3a7c04dd78001db429abb5b28
Source dataset
uspto-grants-1992_06
Patent number
US05118694

Reaction notes

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