m-Chloroperbenzoic acid → 4-chloro-2-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide
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]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
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.