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

HRID 1073905Notes

Reaction equation

HRID 1073905 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]([CH:8]2[C:13]3[CH:14]=[C:15]([C:18]#[N:19])[CH:16]=[CH:17][C:12]=3[O:11][C:10]([CH3:21])([CH3:20])[CH2:9]2)[CH:3]=1.ClC1C=CC=C(C(OO)=[O:30])C=1>ClCCl>[Cl:1][C:2]1[CH:7]=[CH:6][N+:5]([O-:30])=[C:4]([CH:8]2[C:13]3[CH:14]=[C:15]([C:18]#[N:19])[CH:16]=[CH:17][C:12]=3[O:11][C:10]([CH3:21])([CH3:20])[CH2:9]2)[CH:3]=1

Participants

4

Reactant 2

HCID 70297m-Chloroperbenzoic acidHCID 198956254-(4-chloro-2-pyridyl)-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile

Product 1

HCID 536365624-chloro-2-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxideYield 24%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

79 mg of 4-(4-chloro-2-pyridyl)-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile were dissolved in 10 ml of dichloromethane and 70 mg of m-chloroperbenzoic acid were added. The mixture was stirred at room temperature for 3 days, then washed in succession with sodium bisulphite solution, sodium bicarbonate solution and water, dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using 1% (v/v) methanol/ethyl acetate for the elution to give, after trituration with diethyl ether, a solid which was recrystallized from ethyl acetate/petroleum ether. There being obtained 20 mg of 4-chloro-2-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide of melting point 173°-174° C.

Workup

  1. washwashed in succession with sodium bisulphite solution, sodium bicarbonate solution and water
  2. dry with materialdried over sodium sulphate
  3. customevaporated
  4. customThe residue was chromatographed on silica gel using 1% (v/v) methanol/ethyl acetate for the elution
  5. customto give
  6. customafter trituration with diethyl ether, a solid which was recrystallized from ethyl acetate/petroleum ether

Sources & evidence

ORD record
ord-9e14bf268c6b46469a7333497b700884
Source dataset
uspto-grants-1990_11
Patent number
US04971982

Reaction notes

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