2,2-Dimethyl-4-(1-oxidopyridin-1-ium-2-yl)-3,4-dihydrochromene-6-carbonitrile → 2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile

HRID 892519Notes

Reaction equation

HRID 892519 reaction equation
[C:1]([C:3]1[CH:4]=[CH:5][C:6]2[O:11][C:10]([CH3:13])([CH3:12])[CH2:9][CH:8]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][N+:15]=3[O-])[C:7]=2[CH:21]=1)#[N:2]>C(OC(=O)C)(=O)C>[CH3:12][C:10]1([CH3:13])[CH:9]=[C:8]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=2)[C:7]2[CH:21]=[C:3]([C:1]#[N:2])[CH:4]=[CH:5][C:6]=2[O:11]1

Participants

3

Reactant 1

HCID 63363852,2-Dimethyl-4-(1-oxidopyridin-1-ium-2-yl)-3,4-dihydrochromene-6-carbonitrile

Product 1

HCID 156813282,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrileYield 69.1%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

280 mg of 2-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide were heated at 120° C. in 3 ml of acetic anhydride for 24 hours. After cooling the mixture was evaporated and the residue was partitioned between ethyl acetate and aqueous sodium bicarbonate solution. The organic phase was dried over sodium sulphate and evaporated. The residue was recrystallized from cyclohexane to give 181 mg of 2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile which was used without further purification.

Workup

  1. temperatureAfter cooling the mixture
  2. customwas evaporated
  3. customthe residue was partitioned between ethyl acetate and aqueous sodium bicarbonate solution
  4. dry with materialThe organic phase was dried over sodium sulphate
  5. customevaporated
  6. customThe residue was recrystallized from cyclohexane

Sources & evidence

ORD record
ord-a5851f4629aa4332a856258c8b812325
Source dataset
uspto-grants-1992_06
Patent number
US05118694

Reaction notes

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