Phosphorus oxychloride → 2,2-dimethyl-4-chloro-6-cyano-2H-1,3-benzoxazine

HRID 326579Notes

Reaction equation

HRID 326579 reaction equation
P(Cl)(Cl)([Cl:3])=O.[C:6]([C:8]1[CH:9]=[CH:10][C:11]2[O:16][C:15]([CH3:18])([CH3:17])[NH:14][C:13](=O)[C:12]=2[CH:20]=1)#[N:7]>CN(C)C=O>[Cl:3][C:13]1[C:12]2[CH:20]=[C:8]([C:6]#[N:7])[CH:9]=[CH:10][C:11]=2[O:16][C:15]([CH3:18])([CH3:17])[N:14]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 108219722,2-dimethyl-6-cyano-3,4-dihydro-2H-1,3-benzoxazin-4-one

Product 1

HCID 147215882,2-dimethyl-4-chloro-6-cyano-2H-1,3-benzoxazine

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Phosphorous oxychloride (0.5 ml) was added with ice-cooling to dimethylformamide (10 ml) and the mixture was stirred for 10 minutes. To the mixture was added 6-cyano-2,2-dimethyl-3,4-dihydro-2H-1,3-benzoxazin-4-one (1.0 g), and the mixture was stirred with ice-cooling for 1 hour and then at room temperature for 2 hours. The mixture was extracted with addition of ethyl acetate and ice water. The ethyl acetate layer was successively washed with an aqueous sodium bicarbonate solution and saturated saline, dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure. Hexane was added to the residue and 4-chloro-6-cyano-2,2-dimethyl-2H-1,3-benzoxazine (0.41 g, mp. 124°-126° C.) was obtained by crystallization therefrom.

Workup

  1. stirringthe mixture was stirred with ice-
  2. temperaturecooling for 1 hour
  3. waitat room temperature for 2 hours
  4. extractionThe mixture was extracted with addition of ethyl acetate and ice water
  5. washThe ethyl acetate layer was successively washed with an aqueous sodium bicarbonate solution and saturated saline
  6. dry with materialdried over anhydrous magnesium sulfate
  7. distillationThe solvent was distilled off under reduced pressure
  8. additionHexane was added to the residue

Sources & evidence

ORD record
ord-59f07b0f946f4f9e8d5e7ab10ad12c4b
Source dataset
uspto-grants-1993_12
Patent number
US05270308

Reaction notes

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