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

HRID 892543Notes

Reaction equation

HRID 892543 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-9c9e465a7ccd4ad5ba7872076a5bb3b8
Source dataset
uspto-grants-1992_06
Patent number
US05118694

Reaction notes

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