Phosphorus oxychloride → 6-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carbonitrile

HRID 461825Notes

Reaction equation

HRID 461825 reaction equation
P(Cl)(Cl)(Cl)=O.[Cl:6][C:7]1[C:8]([CH3:22])=[CH:9][C:10]2[O:15][C:14]([C:16]([NH2:18])=O)=[CH:13][C:12](=[O:19])[C:11]=2[C:20]=1[CH3:21]>CN(C)C=O>[Cl:6][C:7]1[C:8]([CH3:22])=[CH:9][C:10]2[O:15][C:14]([C:16]#[N:18])=[CH:13][C:12](=[O:19])[C:11]=2[C:20]=1[CH3:21]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 213925996-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carboxamide

Product 1

HCID 213926006-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carbonitrile

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To 400 parts of N,N-dimethylformamide was slowly added 21 parts of phosphorus oxychloride with stirring and ice cooling. Then in small quantities 33.9 parts of 6-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carboxamide was added to the solution. After the addition was completed the reaction mixture was stirred at room temperature for 18 hours. The dark solution which resulted was poured into 1500 parts of ice/water. The precipitated solid was filtered off and crystallised from ethanol to give 30.5 parts of 6-chloro-5,7-dimethyl-4-oxo-4H-1-benzopyran-2-carbonitrile, melting point 142°-143° C.

Workup

  1. additionAfter the addition
  2. stirringwas stirred at room temperature for 18 hours
  3. customThe dark solution which resulted
  4. filtrationThe precipitated solid was filtered off
  5. customcrystallised from ethanol

Sources & evidence

ORD record
ord-a4ea7d7ad5ad4002a55740dbe18a56e8
Source dataset
uspto-grants-1977_12
Patent number
US04064256

Reaction notes

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