Dimethylformamide → 4-[(Dimethylamino)methylidene]-1H-2-benzopyran-1,3(4H)-dione

HRID 1635912Notes

Reaction equation

HRID 1635912 reaction equation
[O-]S([O-])(=O)=O.[Ca+2].O=P(Cl)(Cl)Cl.[C:12]([OH:24])(=[O:23])[CH2:13][C:14]1[C:15](=[CH:19][CH:20]=[CH:21][CH:22]=1)[C:16]([OH:18])=O.[CH3:25][N:26]([CH:28]=O)[CH3:27]>>[CH3:25][N:26]([CH:28]=[C:13]1[C:14]2[CH:22]=[CH:21][CH:20]=[CH:19][C:15]=2[C:16](=[O:18])[O:24][C:12]1=[O:23])[CH3:27]

Participants

5

Reactant 4

HCID 6228Dimethylformamide3×HCID 24497Calcium SulfateHCID 24813Phosphorus oxychlorideHCID 66643Homophthalic acid

Product 1

HCID 714436174-[(Dimethylamino)methylidene]-1H-2-benzopyran-1,3(4H)-dione

Procedure

100 ml of anhydrous DMF in a 1 liter round-bottomed, three necked flask (fitted with a drying tube containing drierite, and a 125 ml dropping funnel) is cooled in an ice-salt bath, and 31 ml of POCl3 is subsequently added over a period of half an hour while stirring the DMF. The 125 ml dropping funnel is replaced with a 150 ml dropping funnel, and a solution of 54 g of homopthalic acid in 100 ml of DMF is added to the flask over a period of one hour at <10° C. The reaction mixture is then stirred at room temperature until a yellow paste was formed, and then poured into ice water. The solid is collected by filtration, washed with water and dried to give 54 g of the title compound as a yellow solid, m.p. 137-40° C.

Workup

  1. temperatureis cooled in an ice-salt bath
  2. customwas formed
  3. filtrationThe solid is collected by filtration
  4. washwashed with water
  5. customdried

Sources & evidence

ORD record
ord-fd680d6d1d004875a406fb81a9a05482
Source dataset
uspto-grants-2003_01
Patent number
US06511987B1

Reaction notes

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