m-Chloroperbenzoic acid → 2-[3,4-dihydro-2,2-dimethyl-6-(4-nitrobenzoyl)-2H-1-benzopyran-4-yl]pyridine N-oxide

HRID 892535Notes

Reaction equation

HRID 892535 reaction equation
[CH3:1][C:2]1([CH3:29])[CH2:7][CH:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][N:9]=2)[C:5]2[CH:14]=[C:15]([C:18](=[O:28])[C:19]3[CH:24]=[CH:23][C:22]([N+:25]([O-:27])=[O:26])=[CH:21][CH:20]=3)[CH:16]=[CH:17][C:4]=2[O:3]1.ClC1C=CC=C(C(OO)=[O:38])C=1>ClCCl>[CH3:1][C:2]1([CH3:29])[CH2:7][CH:6]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][N+:9]=2[O-:38])[C:5]2[CH:14]=[C:15]([C:18](=[O:28])[C:19]3[CH:24]=[CH:23][C:22]([N+:25]([O-:27])=[O:26])=[CH:21][CH:20]=3)[CH:16]=[CH:17][C:4]=2[O:3]1

Participants

4

Reactant 2

HCID 70297m-Chloroperbenzoic acidHCID 198956403,4-dihydro-2,2-dimethyl-6-(4-nitrobenzoyl)-4-(2-pyridyl)-2H-1-benzopyran

Product 1

HCID 542245832-[3,4-dihydro-2,2-dimethyl-6-(4-nitrobenzoyl)-2H-1-benzopyran-4-yl]pyridine N-oxideYield 35.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

134 mg of 3,4-dihydro-2,2-dimethyl-6-(4-nitrobenzoyl)-4-(2-pyridyl)-2H-1-benzopyran were dissolved in 15 ml of dichloromethane and 72 mg of m-chloroperbenzoic acid were added. The mixture was stirred at room temperature overnight. After washing in succession with sodium bisulphite solution and sodium bicarbonate solution the organic phase was dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using ethyl acetate/methanol (4:1) for the elution. The residue was recrystallized from isopropanol to give 50 mg of 2-[3,4-dihydro-2,2-dimethyl-6-(4-nitrobenzoyl)-2H-1-benzopyran-4-yl]pyridine N-oxide of melting point 209°-211° C.

Workup

  1. washAfter washing in succession with sodium bisulphite solution and sodium bicarbonate solution the organic phase
  2. dry with materialwas dried over sodium sulphate
  3. customevaporated
  4. customThe residue was chromatographed on silica gel
  5. washfor the elution
  6. customThe residue was recrystallized from isopropanol

Sources & evidence

ORD record
ord-bc94df84ffa44586a9d61ceb1c1e2dff
Source dataset
uspto-grants-1992_06
Patent number
US05118694

Reaction notes

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