Triethylamine → 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran

HRID 35667Notes

Reaction equation

HRID 35667 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][CH2:8][C:7](=[O:11])[C:6]=2[CH:12]=1.CO[CH:15](OC)[N:16]([CH3:18])[CH3:17].C(N(CC)CC)C>C1C=CC=CC=1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][C:8](=[CH:15][N:16]([CH3:18])[CH3:17])[C:7](=[O:11])[C:6]=2[CH:12]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 78373Dimethylformamide dimethyl acetalHCID 952736-Chlorochroman-4-one

Product 1

HCID 44211356-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyranYield 63.8%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A solution of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran (3.285 g), N,N-dimethylformamide dimethyl acetal (8.568 g), and triethylamine (2.727 g) in benzene (36 ml) was refluxed with stirring for 1 hour and then about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour. To the residue was added benzene (36 ml) and the solvent was distilled again. The residue was dissolved in a mixture of chloroform and ethyl acetate, treated with activated charcoal, and evaporated in vacuo. The residual solid was washed with a mixture of diethyl ether and ethyl acetate to give 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (2.73 g).

Workup

  1. distillationabout three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour
  2. additionTo the residue was added benzene (36 ml)
  3. distillationthe solvent was distilled again
  4. dissolutionThe residue was dissolved in a mixture of chloroform and ethyl acetate
  5. additiontreated with activated charcoal
  6. customevaporated in vacuo
  7. washThe residual solid was washed with a mixture of diethyl ether and ethyl acetate

Sources & evidence

ORD record
ord-9bc50362b475408bb4ffb2ac0b607a43
Source dataset
uspto-grants-1988_08
Patent number
US04767780

Reaction notes

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