Phosphorus oxychloride → 4H-1-Benzopyran-2-carbonitrile, 7-methyl-4-oxo-

HRID 1090774Notes

Reaction equation

HRID 1090774 reaction equation
P(Cl)(Cl)(Cl)=O.[C:6]([C:9]1[O:10][C:11]2[CH:19]=[C:18]([CH3:20])[CH:17]=[CH:16][C:12]=2[C:13](=[O:15])[CH:14]=1)(=O)[NH2:7]>CN(C)C=O>[C:6]([C:9]1[O:10][C:11]2[CH:19]=[C:18]([CH3:20])[CH:17]=[CH:16][C:12]=2[C:13](=[O:15])[CH:14]=1)#[N:7]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 2146214H-1-Benzopyran-2-carboxamide, 7-methyl-4-oxo-

Product 1

HCID 2146224H-1-Benzopyran-2-carbonitrile, 7-methyl-4-oxo-Yield 70.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

26.41g (17.22 mmoles) of phosphorus oxychloride is added to 100 ml dimethylformamide at 0° C. and stirred at 0° C. for 15 minutes at room temperature for 30 minutes. 7.0g (34.45 mmoles) 2-carbamyl-7-methyl-4-oxo-4H-1-benzopyran is added and the mixture stirred at room temperature overnight, then poured into ice water and is allowed to stand for 1 hour at room temperature. The resulting precipitate is filtered off, redissolved in ethyl acetate, decolorized with carbon, filtered and the filtrate concentrated in vacuo to give 4.5g of 2-cyano-7-methyl-4-oxo-4H-1-benzopyran as a crystalline solid having an m.p. of 155°-56° C.

Workup

  1. stirringthe mixture stirred at room temperature overnight
  2. waitto stand for 1 hour at room temperature
  3. filtrationThe resulting precipitate is filtered off
  4. dissolutionredissolved in ethyl acetate
  5. filtrationfiltered
  6. concentrationthe filtrate concentrated in vacuo

Sources & evidence

ORD record
ord-e17da578e49247ec87208fdcf698878a
Source dataset
uspto-grants-1992_01
Patent number
US05082849

Reaction notes

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